Polishing pad and method of manufacturing semiconductor device

Abstract

The present application relates to a kind of polishing pad and the manufacturing method of semiconductor device.The polishing pad, by the structure design of subdivision in thickness direction, can provide the physical property in line with various polishing purposes for various polishing objects, and in the aspect of abandonment after use, unlike existing polishing pad, renewable material or recyclable material is applied in at least part of structure, so as to ensure environmental protection.Specifically, the polishing pad includes polishing layer;The polishing layer includes: polishing variable layer, with polishing surface, and polishing invariable layer, is arranged in the opposite side of the polishing surface of the polishing variable layer;The polishing invariable layer includes the solidified product of first composition containing first urethane-based prepolymer, the first urethane-based prepolymer can be the reaction product of first alcohol component and first isocyanate component, and the first alcohol component includes the first polyol with hydroxyl value of 200mgKOH / g to 900mgKOH / g.

Description

TECHNICAL FIELD

[0001] The present invention relates to a polishing pad for a polishing process and a method of manufacturing a semiconductor device using the pad. BACKGROUND

[0002] A chemical mechanical planarization (CMP) or chemical mechanical polishing (CMP) process can be used for various purposes in various technical fields. The CMP process is performed on a predetermined polished surface of a polishing object, and can be used for planarizing the polished surface, removing agglomerated substances, solving lattice damage, removing scratches and contamination sources, and the like.

[0003] CMP process techniques for semiconductor processes can be classified according to the polishing object film quality or the shape of the polished surface. For example, they can be classified as single silicon or polysilicon according to the polishing object film quality, and as various oxide film or metal film CMP processes for tungsten (W), copper (Cu), aluminum (Al), ruthenium (Ru), tantalum (Ta), and the like according to the type of impurities. Also, they can be classified as a process for improving the roughness of a substrate surface, a process for planarizing a step difference caused by a multilayer circuit wiring, and a device separation process for selectively forming a circuit wiring after polishing, according to the shape of the polished surface.

[0004] The CMP process can be applied several times during the manufacturing process of a semiconductor device. The semiconductor device includes a plurality of layers, and each layer includes a complex and fine circuit pattern. Also, in recent semiconductor devices, the size of a single chip is reduced, and the pattern of each layer is evolving toward a more complex and fine direction. Therefore, the purpose of the CMP process during the manufacturing process of a semiconductor device has been expanded to include not only planarization of a circuit wiring, but also separation of the circuit wiring and improvement of the wiring surface, and as a result, more precise and reliable CMP performance is being required.

[0005] Such a polishing pad for a CMP process, which is a process member for processing a polished surface to a desired level by friction, can be considered as one of the most important factors in the uniformity of the thickness of the polished object after polishing, the flatness of the polished surface, the polishing quality, and the like. SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In one embodiment of the present application, a polishing pad is provided, which is designed to provide physical properties in accordance with various polishing purposes for various polishing targets by being subdivided in the thickness direction, and in which polishing performance does not decrease over time based on appropriate variability in structural changes during the polishing process. In addition, in the aspect of disposal of the polishing pad after use, unlike conventional polishing pads, the purpose of environmental protection is achieved by applying a renewable material or a recyclable material to at least a portion of the structure.

[0008] In another embodiment of the present application, a method of manufacturing a semiconductor device is provided, which applies the polishing pad to ensure the diversity of polished surfaces of a semiconductor substrate, and to ensure excellent polishing flatness and the lowest degree of defect occurrence while ensuring appropriate polishing rates for each polished surface, thereby achieving improved results in terms of process productivity and economics.

[0009] Means for solving the problem

[0010] In one embodiment of the present application, a polishing pad is provided, which includes a polishing layer; the polishing layer includes a polishing variable layer having a polishing surface, and a polishing invariable layer disposed on the side opposite to the polishing surface of the polishing variable layer; the polishing invariable layer includes a cured product of a first composition containing a first urethane-based prepolymer, the first urethane-based prepolymer being a reaction product of a first alcohol component and a first isocyanate component, the first alcohol component including a first polyol having a hydroxyl number (OH-Value) of 200 mgKOH / g to 900 mgKOH / g.

[0011] The interface between the polishing variable layer and the polishing invariable layer can be a separable interface.

[0012] The polishing variable layer and the polishing invariable layer can each include at least one layer.

[0013] The isocyanate group (-NCO) content of the first composition can be 8% by weight to 20% by weight.

[0014] The first composition further includes a first curing agent, and the first curing agent can include a compound containing one reaction group selected from the group consisting of an amino group, a hydroxyl group, and combinations thereof.

[0015] The first curing agent includes a compound containing a hydroxyl group (-OH) as the reaction group, and the compound containing the hydroxyl group can have a hydroxyl number of greater than 600 mgKOH / g and 900 mgKOH / g or less.

[0016] The polishing variable layer includes a cured product of a second composition including a second urethane-based prepolymer, which can be a reaction product of a second alcohol component and a second isocyanate component, the second alcohol component including a second polyol having a hydroxyl value of 50 mgKOH / g or more and less than 200 mgKOH / g.

[0017] The second composition further includes a second curing agent, which can include a compound including a reaction group selected from the group consisting of an amino group (-NH2), a hydroxyl group, and combinations thereof.

[0018] The second curing agent includes a compound including an amino group as the reaction group, and a molar ratio of isocyanate groups in the second composition to amino groups in the second curing agent can be 1:0.80 to 1:1.20.

[0019] The content of isocyanate groups in the second composition can be 5% by weight to 11% by weight.

[0020] In another embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, including the steps of: providing a polishing pad on a flat plate, the polishing pad including a polishing layer having a polishing surface, and disposing a polished surface of a polishing object in contact with the polishing surface, and then polishing the polishing object under a pressurized condition while rotating the polishing pad and the polishing object relative to each other; the polishing layer including: a polishing variable layer including the polishing surface, and a polishing invariable layer disposed on a side opposite the polishing surface of the polishing variable layer; the polishing invariable layer including a cured product of a first composition including a first urethane-based prepolymer, which is a reaction product of a first alcohol component and a first isocyanate component, the first alcohol component including a first polyol having a hydroxyl value of 200 mgKOH / g to 900 mgKOH / g.

[0021] The polished surface of the polishing object can be pressurized to the polishing surface of the polishing layer at a load of 0.01 psi to 20 psi.

[0022] Effects of the Invention

[0023] The polishing pad can provide physical properties that conform to various polishing purposes for various polishing objects through a structure design that is subdivided in the thickness direction, and in terms of structural changes during a polishing process, the polishing performance does not decrease for a long time based on appropriate variability. In addition, in terms of disposal after use of the polishing pad, unlike existing polishing pads, environmental protection can be ensured by applying a renewable material or a recyclable material to at least a portion of the structure.

[0024] The semiconductor device manufacturing method, the application of the polishing pad, can ensure the diversity of the polished surface of the semiconductor substrate, and can ensure excellent polishing flatness and the lowest defect occurrence while ensuring the appropriate polishing rate for each polished surface, and can lead to improved results in process productivity and economy. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A cross section of the polishing layer of an embodiment is schematically shown.

[0026] Figure 2 A change in the first surface in a polishing process of an embodiment is schematically shown.

[0027] Figure 3 A cross section of the polishing pad of an embodiment is schematically shown.

[0028] Figure 4 A schematic view of a semiconductor device manufacturing method of an embodiment is schematically shown.

[0029] 110: Polishing pad

[0030] 10: Polishing layer

[0031] 101: Polishing variable layer

[0032] 102: Polishing invariable layer

[0033] 11: First surface

[0034] 12: Second surface

[0035] 13: Separable interface

[0036] 14: Groove

[0037] 20: Buffer layer

[0038] 30: First adhesive layer

[0039] 40: Second adhesive layer

[0040] w1: Width of groove

[0041] p1: Pitch of groove

[0042] d1: Depth of groove

[0043] D1: Thickness of polishing variable layer

[0044] 15: Pore

[0045] 120: Flat plate

[0046] 130: Polishing object

[0047] 140: nozzle

[0048] 150: polishing slurry

[0049] 160: polishing head

[0050] 170: dresser DETAILED DESCRIPTION

[0051] Advantages, features, and methods of implementing the present application will become more apparent from the following detailed description of implementations or embodiments. However, the present application is not limited to the implementations or embodiments disclosed below, but can be implemented in various forms. The implementations or embodiments described below are merely to make the present application more complete and to provide those skilled in the art to which the present application pertains with the scope of the present application, and the scope of the present application is defined by the scope of claims.

[0052] In the drawings, a thickness of a part is exaggerated for the sake of clarity in expressing layers or regions in the drawings as necessary. Also, in the drawings, thicknesses of some layers and regions are exaggerated for the convenience of explanation. Throughout the specification, the same reference numerals denote the same constituent elements.

[0053] In the present specification, when a part of a layer, film, region, plate, or the like is referred to as being "on" or "above" another part, this includes not only a case where the part is directly on or above the other part, but also a case where there is still another part therebetween. In contrast, when a part is referred to as being directly on or above another part, it means that there is no other part therebetween. Meanwhile, when a part of a layer, film, region, plate, or the like is referred to as being "under" or "below" another part, this includes not only a case where the part is directly under or below the other part, but also a case where there is still another part therebetween. In contrast, when a part is referred to as being directly under or below another part, it means that there is no other part therebetween.

[0054] In the description of numerical ranges in the present specification, the meaning of "to or above" is interpreted as including the number itself or a case of being greater than it. For example, "two or more" means a case of two or greater than two. In addition, the description of "X to Y" in a numerical range is interpreted as a range including X or Y. For example, "25 to 50" means a numerical range including 25 and 50.

[0055] In the present specification, with respect to structures labeled with "first" or "second" and the like, the parent structures including them are different from each other, and in order to distinguish them, the structures are labeled and described, but this description method itself should not be interpreted as including components or different compositions different from each other.

[0056] Hereinafter, implementations of the present application will be described in detail.

[0057] In one embodiment, there is provided a polishing pad including a polishing layer; the polishing layer includes a polishing variable layer having a polishing surface, and a polishing invariable layer provided on the side opposite to the polishing surface of the polishing variable layer; the polishing invariable layer includes a cured product of a first composition containing a first urethane-based prepolymer, the first urethane-based prepolymer being a reaction product of a first alcohol component and a first isocyanate component, the first alcohol component containing a first polyol having a hydroxyl value of 200 mgKOH / g to 900 mgKOH / g.

[0058] Figure 1 A cross section in the thickness direction of the polishing layer 10 of one embodiment is schematically shown. Hereinafter, a "polishing surface" and a "first surface" can be used as terms for indicating the same structure.

[0059] With reference to Figure 1 The polishing layer 10 can include a polishing variable layer 101 having a polishing surface 11. In addition, the polishing layer 10 can include a polishing invariable layer 102 provided on the side opposite to the polishing surface 11. The interface between the polishing variable layer 101 and the polishing invariable layer 102 can be a separable interface. The polishing variable layer 101 and the polishing invariable layer 102 can each include at least one layer.

[0060] On the other hand, the polishing layer 10 can include a first surface 11 and a second surface 12 as the opposite surface of the first surface 11. In addition, the polishing layer 10 can include at least one separable interface 13 between the first surface 11 and the second surface 12. In this specification, the "separable interface" refers to an interface capable of substantially dividing two layers adjacent to the separable interface into a discontinuous structure rather than a continuous structure. As one example, the separable interface can correspond to an attachment surface or the like as an interface that is detached or separated under a prescribed external force.

[0061] The polishing layer 10 can include at least one polishing variable layer 101 as a region from the first surface 11 to the detachable interface 13, and at least one polishing invariable layer 102 as a region from the detachable interface 13 to the second surface 12. In the present specification, the "polishing variable layer" refers to a region in which physical characteristics such as structure, shape, and / or chemical characteristics such as composition are changed in a polishing process using the polishing pad, and the "polishing invariable layer" refers to a region in which physical and / or chemical characteristics are not substantially changed in a polishing process using the polishing pad. The meaning of "not substantially changed" can be interpreted to include not only a case in which physical and / or chemical characteristics are not changed at all, but also a case in which physical and / or chemical characteristics can be slightly changed due to polishing in a pressurized and humidified environment, but the level of change is so slight compared to the polishing variable layer that it can be considered as not substantially changed.

[0062] Figure 1 The case in which one detachable interface 13 is formed is schematically shown, but the polishing layer 10 can include at least two detachable interfaces 13 between the first surface 11 and the second surface 12 as needed. In this case, the polishing variable layer 101 or the polishing invariable layer 102 can each include a plurality of layers.

[0063] The polishing layer 10 can be designed to include at least one polishing variable layer 101 and at least one polishing invariable layer 102, and as a result of the properties of the organic interaction of the respective layers stacked in the thickness direction in the above-described manner, the polishing performance calculated from the polishing surface 11 can be finely and accurately controlled according to the purpose.

[0064] In an embodiment, the polishing variable layer 101 can account for about 30% to about 60% by volume of the entire volume of the polishing layer 10, for example, can account for about 40% to about 60% by volume, for example, can account for about 45% to about 55% by volume. When the volume of the polishing variable layer 101 in the entire volume of the polishing layer 10 satisfies the above-described range, it can be advantageous to achieve the process life of the polishing pad to the purpose level while ensuring the above-described technical advantages achieved by the polishing variable layer 101 and the polishing invariable layer 102.

[0065] The polishing pad can be used in polishing processes for various purposes. For example, the polishing pad can be applied to a manufacturing process of a semiconductor device. Recently, the degree of integration of semiconductor devices has been increasingly required, and the structure thereof has been increasingly complicated in a three-dimensional form. To meet such a requirement, fine process control needs to be implemented in the manufacturing process of the semiconductor device. The semiconductor device includes thin films of various materials and various shapes, and thus a polishing process that finely adjusts process conditions according to the materials and shapes of the respective thin films is required. The polishing pad, as one of such fine process control factors, can also cause significant differences in polishing results of the semiconductor device due to fine differences in the structure, material, and shape of the polishing pad.

[0066] The polishing invariant layer 102, as described above, is a region whose physical and / or chemical characteristics do not substantially change in a polishing process, does not directly affect the polished surface of a polishing object, but can function as a structure that directly or indirectly affects the final polishing performance by supporting the overall structure of the polishing pad to an appropriate level in terms of physical / mechanical properties such as structural support performance, elasticity, elongation, and tensile strength.

[0067] In this regard, the polishing invariant layer 102 includes a cured product of a first composition including a first urethane-based prepolymer, and technical advantages thereof can be maximized by using, as the first urethane-based prepolymer, a reaction product of a first isocyanate component and a first alcohol component including a first polyol having a hydroxyl value of 200 mgKOH / g to 900 mgKOH / g.

[0068] In the first urethane-based prepolymer, the "prepolymer" refers to a polymer having a relatively low molecular weight, which is interrupted in an intermediate stage for the purpose of facilitating molding in terms of polymerization degree when a cured product is prepared. The prepolymer itself can be finally molded into a cured product through an additional curing process such as heating and / or pressurization, or mixed with and reacted with an additional compound such as a different kind of monomer or a different kind of prepolymer to be finally molded into a cured product.

[0069] In the present specification, the "polyol" refers to a compound including at least two hydroxyl groups per molecule. In an implementation example, the polyol compound can include a diol compound including two hydroxyl groups, i.e., a diol or a glycol, or a triol compound including three hydroxyl groups, i.e., a triol compound.

[0070] In an embodiment, the first polyol can be a recycled polyol. Specifically, the first polyol can be a polyol derived from a polishing pad waste. More specifically, the first polyol can be a polyol derived from a hydrolysis product of the polishing pad waste. The "polishing pad waste" can refer to a polishing pad that is discarded after use in a polishing process; or a by-product that is discarded during a polishing pad manufacturing process. Generally, a polishing pad is used as a semi-permanent process component, and is one of the components that needs to be replaced after a predetermined time of use in a polishing process, because its physical structure and / or chemical properties are no longer suitable for polishing. Also, since a polishing pad is required to provide a polishing surface that meets the polishing purpose, in most cases, only a portion that ensures the quality stability of a polishing object is used during the manufacturing process of the polishing pad, and the remaining portion is discarded as a by-product. As described above, in the case where a used polishing pad or a polishing pad by-product discarded during a manufacturing process contains a thermosetting polyurethane, the polishing pad or the polishing pad by-product is not substantially recyclable, and thus is becoming a major factor in environmental pollution. Further, as the demand for semiconductors has recently increased, the amount of polishing pads and polishing pad by-products discarded after being used in semiconductor processes and the like has continuously increased, and thus the environmental pollution problem is gradually deepening. Accordingly, when a recycled polyol derived from the polishing pad waste is applied as a structure of the polishing invariant layer 102, the technical purpose described above can be achieved while achieving the advantage of an environmentally friendly effect.

[0071] In the first polyol, the hydroxyl value can be about 200 mgKOH / g to about 900 mgKOH / g, for example, about 300 mgKOH / g to about 900 mgKOH / g, for example, about 300 mgKOH / g to about 800 mgKOH / g, for example, about 300 mgKOH / g to about 750 mgKOH / g, for example, about 450 mgKOH / g to about 650 mgKOH / g. In the case where a polyol having the hydroxyl value is used as the first polyol, when used together with the polishing variable layer, the physical and / or mechanical properties of the polishing invariant layer derived from the first polyol can be advantageous in achieving polishing performance. Also, it can be more advantageous to obtain the first polyol as a recycled polyol by processing from the polishing pad waste. That is, in the case where the first polyol is a recycled polyol derived from a hydrolysis (Glycolysis) product of the polishing pad waste, the recycled polyol can be made into an alcohol compound having at least two terminal hydroxyl groups by decomposing a polymer chain constituting the polishing pad in a predetermined unit, and the first polyol obtained in this way can more easily satisfy the hydroxyl value.

[0072] The first polyol can have a weight average molecular weight (Mw) of about 100 g / mol to about 1200 g / mol, for example, about 100 g / mol to about 1000 g / mol, for example, about 100 g / mol to about 950 g / mol, for example, about 100 g / mol to about 800 g / mol, for example, about 100 g / mol to about 750 g / mol, for example, about 100 g / mol to about 700 g / mol, for example, about 100 g / mol to about 650 g / mol, for example, about 150 g / mol to about 600 g / mol. When the first polyol has a backbone structure corresponding to the molecular weight, the first alcohol component and the first isocyanate component react with each other, thereby a generally homogeneous polyurethane material can be formed, and as described above, it can be more advantageous to obtain the first polyol as a recycled polyol from the polishing pad waste through processing.

[0073] In an implementation, the first alcohol component can include an additional polyol compound in addition to the first polyol. The additional polyol compound, for example, can include one selected from the group consisting of a polyether polyol, a polyester polyol, a polycarbonate polyol, an acryl polyol, and combinations thereof.

[0074] Specifically, the additional polyol compound, for example, can include one selected from the group consisting of a polytetramethylene ether glycol (PTMG), a polypropylene ether glycol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol (DEG), dipropylene glycol (DPG), tripropylene glycol, polypropylene glycol, polypropylene triol, and combinations thereof.

[0075] The first isocyanate component can be one selected from the group consisting of an aromatic diisocyanate, an aliphatic diisocyanate, a cycloaliphatic diisocyanate, and combinations thereof. For example, the first isocyanate component can include an aromatic diisocyanate.

[0076] The first isocyanate component may, for example, include one selected from the group consisting of 2,4-toluenediisocyanate (2,4-TDI), 2,6-toluenediisocyanate (2,6-TDI), naphthalene-1,5-diisocyanate, p-phenylenediisocyanate, tolylene diisocyanate, 4,4'-diphenylmethanediisocyanate, hexamethylenediisocyanate, dicyclohexylmethanediisocyanate, 4,4'-dicyclohexylmethanediisocyanate (H 12 MDI), isophoronediisocyanate, and combinations thereof.

[0077] In an embodiment, the first isocyanate component includes an aromatic diisocyanate. The aromatic diisocyanate may, for example, include 2,4-toluenediisocyanate (2,4-TDI), may, for example, include 2,4-toluenediisocyanate (2,4-TDI) and 2,6-toluenediisocyanate (2,6-TDI).

[0078] In an embodiment, the first polyol may be about 10 parts by weight to about 30 parts by weight, for example, about 15 parts by weight to about 20 parts by weight, relative to 100 parts by weight of the total weight of the first isocyanate component. When the first polyol is used in the above range of relative content ratio relative to the first isocyanate component, the properties of the polished invariable layer derived from the first urethane-based prepolymer can be more advantageous to improve the polishing performance to the desired level.

[0079] The content of isocyanate groups (NCO%) in the first isocyanate component can be about 30% by weight to about 65% by weight, for example, can be about 35% by weight to about 60% by weight, for example, can be about 40% by weight to about 55% by weight, for example, can be about 40% by weight to about 50% by weight. The "content of isocyanate groups (NCO%)" of the first isocyanate component refers to the percentage of the weight of isocyanate groups (-NCO) that are present in the form of free reactive groups without having reacted in the corresponding component. When the NCO% of the first isocyanate component satisfies the above range, optimal reactivity with the first polyol can be achieved. More specifically, when the hydroxyl value and / or the weight average molecular weight satisfy the above ranges, respectively, advantages in reactivity with the first polyol can be achieved.

[0080] The content of isocyanate groups (NCO%) in the first composition can be about 8% by weight to 20% by weight, for example, can be about 8% by weight to about 18% by weight, for example, can be about 8% by weight to about 15% by weight, for example, can be about 9% by weight to about 15% by weight, for example, can be about 10% by weight to about 15% by weight, for example, can be greater than about 10% by weight and about 15% by weight or less. The "content of isocyanate groups (NCO%)" in the first composition refers to the percentage of the weight of isocyanate groups (-NCO) that are present in the form of free reactive groups without having reacted in the composition. The NCO% of the first composition can be calculated based on the total weight of the first composition excluding the first curing agent and the first blowing agent described later. When the NCO% of the first composition satisfies the above range, the polishing invariable layer prepared by curing the first composition can have an optimal crosslinked structure, as a result of which the polishing invariable layer laminated with the polishing variable layer can be more advantageous in providing excellent polishing performance through the first surface 11 in the overall structure.

[0081] The first composition can further include a first curing agent. The first curing agent chemically reacts with the first urethane-based prepolymer to form an appropriate crosslinked structure, thereby imparting appropriate mechanical properties to the polishing invariable layer, and can function to improve the lamination compatibility of the polishing invariable layer and the polishing variable layer.

[0082] In an embodiment, the first curing agent can include a compound including one reactive group selected from the group consisting of an amino group, a hydroxyl group, and combinations thereof. The "reactive group" refers to a terminal group that directly participates in a chemical reaction when the first curing agent reacts with a different kind of compound such as the first urethane-based prepolymer. That is, the first curing agent, for example, can include a compound including an amino group as a reactive group in one molecule, or a compound including a hydroxyl group as a reactive group in one molecule, or a compound including both an amino group and a hydroxyl group as reactive groups in one molecule.

[0083] For example, the first curing agent can include one selected from the group consisting of 4,4'-methylenebis(2-chloroaniline) (MOCA), diethyltoluenediamine (DETDA), diaminodiphenylmethane, dimethylthio-toluene diamine (DMTDA), propanediol bis p-aminobenzoate, Methylene bis-methylanthranilate, diaminodiphenylsulfone, m-xylylenediamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, bis(4-amino-3-chlorophenyl)methane, triethanolamine, tripropanolamine, triisopropanolamine, and combinations thereof.

[0084] For example, the first curing agent can include a compound including a hydroxyl group as the reactive group. In this case, the hydroxyl value of the compound can be greater than about 600 mgKOH / g and less than about 900 mgKOH / g, for example, can be about 650 mgKOH / g to about 850 mgKOH / g, for example, can be about 700 mgKOH / g to about 800 mgKOH / g. In the case of using a compound having the hydroxyl value as the first curing agent, the chemical structure reactivity upon reaction with the first urethane-based prepolymer derived from the first polyol having a hydroxyl value within the above range can be improved, as a result of which the cured structure as a whole can be advantageous in imparting improved mechanical properties to the polishing resist layer.

[0085] In an embodiment, in the case where the first curing agent includes a compound including a hydroxyl group as the reactive group, the molar ratio (NCO:OH) of the isocyanate group (-NCO) present as a free reactive group in the first composition and the hydroxyl group (-OH) derived from the first curing agent can be about 1:2 to about 2:1, for example, can be about 1:1.5 to about 1.5:1, for example, can be about 1:1.2 to about 1.2:1. When the first curing agent satisfying the molar ratio is used, the crosslinking structure between the first urethane-based prepolymer and the first curing agent can be more advantageous in improving the mechanical properties of the polishing resist layer.

[0086] The content of the first curing agent in the first composition as a whole can be about 15 wt% to about 30 wt%, for example, can be about 18 wt% to about 27 wt%, for example, can be about 19 wt% to about 26 wt%, for example, can be about 20 wt% to about 26 wt%. When the first curing agent is used in the content, the crosslinking structure between the first urethane-based prepolymer and the first curing agent can be more advantageous in improving the mechanical properties of the polishing resist layer.

[0087] The first composition can further include a first blowing agent as needed. The first blowing agent can function to adjust the density and elasticity by imparting a cell structure to the polishing resist layer. The first blowing agent, for example, can include one selected from the group consisting of a solid blowing agent, a gas blowing agent, a liquid blowing agent, and combinations thereof.

[0088] In the case where the first composition further includes the first blowing agent, the content of the first blowing agent can be about 0.1 parts by weight to about 10 parts by weight, for example, about 0.1 parts by weight to about 5 parts by weight, with respect to 100 parts by weight of the first composition as a whole.

[0089] The polishing variable layer 101 can include a cured product of a second composition including a second urethane-based prepolymer. In the second urethane-based prepolymer, the "prepolymer" refers to a high molecule having a relatively low molecular weight in which the degree of polymerization is interrupted in an intermediate stage for the purpose of facilitating molding at the time of producing a cured product. The prepolymer itself can be finally molded into a cured product by an additional curing process such as heating and / or pressurization, or mixed with and reacted with an additional compound such as a different kind of monomer or a different kind of prepolymer, and finally molded into a cured product.

[0090] In an embodiment, the second urethane-based prepolymer can be a reaction product of a second alcohol component and a second isocyanate component, the second alcohol component including a second polyol having a hydroxyl value of about 50 mgKOH / g or more and less than about 200 mgKOH / g. The second alcohol component and the second isocyanate component can each include the same compound or a different compound as the first alcohol component and the first isocyanate component, respectively.

[0091] In an embodiment, the second isocyanate component can be one selected from the group consisting of an aromatic diisocyanate, an aliphatic diisocyanate, a cycloaliphatic diisocyanate, and combinations thereof. For example, the second isocyanate component can include an aromatic diisocyanate. For example, the second isocyanate component can include an aromatic diisocyanate and a cycloaliphatic diisocyanate.

[0092] The second isocyanate component, for example, can include one selected from the group consisting of 2,4-toluenediisocyanate (2,4-TDI), 2,6-toluenediisocyanate (2,6-TDI), naphthalene-1,5-diisocyanate, p-phenylenediisocyanate, tolylene diisocyanate, 4,4'-diphenylmethanediisocyanate, hexamethylenediisocyanate, dicyclohexylmethanediisocyanate, 4,4'-dicyclohexylmethanediisocyanate (H 12one of the group consisting of 4,4'-diphenylmethane diisocyanate (MDI), isophorone diisocyanate, and combinations thereof.

[0093] The second alcohol component can include a second polyol having a hydroxyl value of about 50 mgKOH / g or more and less than about 200 mgKOH / g. In the second polyol, "polyol" refers to a compound including at least two hydroxyl groups per molecule. When the first composition for preparing the polishing invariable layer includes a first polyol having a hydroxyl value satisfying the above range as the first alcohol component, and the second composition for preparing the polishing variable layer includes the second polyol having a hydroxyl value of about 50 mgKOH / g or more and less than about 200 mgKOH / g as the second alcohol component, the physical properties of each of the polishing variable layer and the polishing invariable layer are combined with each other, so that the characteristics in the thickness direction of the polishing layer as a whole can be more advantageous in terms of ensuring polishing performance.

[0094] The second polyol can have a hydroxyl value of about 50 mgKOH / g or more and less than about 200 mgKOH / g, for example, about 80 mgKOH / g or more and less than about 200 mgKOH / g, for example, about 100 mgKOH / g to about 190 mgKOH / g, for example, about 100 mgKOH / g to about 180 mgKOH / g, for example, about 105 mgKOH / g to about 140 mgKOH / g, for example, about 105 mgKOH / g to about 130 mgKOH / g. In the case of using a polyol having the hydroxyl value as the second polyol, the physical and / or mechanical properties of the polishing variable layer prepared from the second polyol can be more advantageous in terms of polishing performance when used together with the polishing invariable layer.

[0095] The second polyol can have a weight average molecular weight (Mw) of about 100 g / mol to about 3000 g / mol, for example, about 100 g / mol to about 2000 g / mol, for example, about 100 g / mol to about 1800 g / mol, for example, about 300 g / mol to about 1800 g / mol. When the second polyol has a main chain structure corresponding to the molecular weight, the second alcohol component and the second isocyanate component react with each other, so that the hardness and elongation that are advantageous in improving polishing performance can be ensured as a whole.

[0096] In an implementation example, the second alcohol component can include an additional polyol compound in addition to the second polyol.

[0097] The additional polyol compound, for example, can include one selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, acryl polyols, and combinations thereof.

[0098] Specifically, the additional polyol compound, for example, can include one selected from the group consisting of polypropylene ether glycol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol (DEG), dipropylene glycol (DPG), tripropylene glycol, polypropylene glycol, polypropylene triol, and combinations thereof.

[0099] In an embodiment, the weight average molecular weight (Mw) of the additional polyol compound in the second alcohol component can be about 100 g / mol or more and less than about 300 g / mol. In this case, the second alcohol component can form a proper crosslinking structure in the second urethane-based prepolymer, as a result of which the polishing variable layer 101 exhibits proper tensile strength, elongation, and compression characteristics, and thus can be more advantageous in improving the polishing performance through the first surface 11.

[0100] The weight average molecular weight (Mw) of the second urethane-based prepolymer can be about 500 g / mol to about 3000 g / mol, for example, can be about 600 g / mol to about 2000 g / mol, for example, can be about 800 g / mol to about 1000 g / mol. In the case where the second urethane-based prepolymer has a degree of polymerization corresponding to the weight average molecular weight (Mw), the polishing variable layer 101 including a final cured product exhibits proper surface hardness and tensile strength, and thus can be more advantageous in improving the polishing performance through the first surface 11.

[0101] In an embodiment, the second isocyanate component can include an aromatic diisocyanate. The aromatic diisocyanate, for example, can include 2,4-toluene diisocyanate (2,4-TDI), for example, can include 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI). In addition, the second polyol, for example, can include polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

[0102] In another embodiment, the second isocyanate component can include an aromatic diisocyanate and a cycloaliphatic diisocyanate. The aromatic diisocyanate, for example, can include 2,4-toluene diisocyanate (2,4-TDI), for example, can include 2,4-toluene diisocyanate (2,4-TDI) with 2,6-toluene diisocyanate (2,6-TDI). The cycloaliphatic diisocyanate, for example, can include 4,4'-dicyclohexylmethane diisocyanate (H 12 MDI). Additionally, the second polyol, for example, can include polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

[0103] In one embodiment, the total weight of the second alcohol component can be about 100 parts by weight to about 180 parts by weight, for example, can be greater than about 100 parts by weight and about 180 parts by weight or less, for example, can be about 110 parts by weight to about 160 parts by weight, for example, can be about 120 parts by weight to about 150 parts by weight, relative to 100 parts by weight of the total weight of the second isocyanate component.

[0104] In another embodiment, the total weight of the second alcohol component can be greater than about 180 parts by weight and about 250 parts by weight or less, for example, can be about 185 parts by weight to about 250 parts by weight, for example, can be about 190 parts by weight to about 240 parts by weight, relative to 100 parts by weight of the total weight of the second isocyanate component.

[0105] In one embodiment, the second polyol includes polytetramethylene ether glycol (PTMG), and the content of the second polyol can be about 100 parts by weight to about 250 parts by weight, for example, can be greater than about 100 parts by weight and about 250 parts by weight or less, for example, can be about 110 parts by weight to about 220 parts by weight, for example, can be about 110 parts by weight to about 140 parts by weight, relative to 100 parts by weight of the total weight of the second isocyanate component.

[0106] In another embodiment, the second polyol includes polytetramethylene ether glycol (PTMG), and the content of the second polyol can be about 150 parts by weight to about 250 parts by weight, for example, can be about 180 parts by weight to about 230 parts by weight, relative to 100 parts by weight of the total weight of the second isocyanate component.

[0107] In one embodiment, the additional polyol compound of the second alcohol component includes diethylene glycol (DEG), and the content of the diethylene glycol (DEG) can be about 1 part by weight to about 20 parts by weight, for example, can be about 1 part by weight to about 15 parts by weight, relative to 100 parts by weight of the total weight of the second isocyanate component.

[0108] In an embodiment, the second isocyanate component contains the aromatic diisocyanate containing 2,4-TDI and 2,6-TDI, and the content of the 2,6-TDI can be about 1 part by weight to about 40 parts by weight, for example, can be about 1 part by weight to about 30 parts by weight, for example, can be about 3 parts by weight to about 28 parts by weight, for example, can be about 20 parts by weight to about 30 parts by weight, with respect to 100 parts by weight of the 2,4-TDI.

[0109] In another embodiment, the content of the 2,6-TDI can be about 1 part by weight to about 40 parts by weight, for example, can be about 1 part by weight to about 30 parts by weight, for example, can be about 1 part by weight to about 20 parts by weight, for example, can be about 1 part by weight to about 10 parts by weight, with respect to 100 parts by weight of the 2,4-TDI.

[0110] In an embodiment, the second isocyanate component contains the aromatic diisocyanate and the alicyclic diisocyanate, and the content of the alicyclic diisocyanate can be about 5 parts by weight to about 30 parts by weight, for example, can be about 10 parts by weight to about 25 parts by weight, with respect to total 100 parts by weight of the aromatic diisocyanate.

[0111] In the case where the second urethane-based prepolymer satisfies the above component characteristics, the polishing variable layer can ensure physical / mechanical properties for achieving the desired variability. In addition, improved processability in forming additional structures such as grooves on the first surface of the polishing variable layer can be ensured. In addition, in the polishing layer overall structure laminated with the polishing invariable layer, it can be more advantageous to ensure the best uniformity in terms of achieving the subdivision of properties in the thickness direction and the polishing performance.

[0112] The isocyanate group content (NCO%) in the second composition can be about 5% by weight to about 11% by weight, for example, can be about 5% by weight to about 10% by weight, for example, can be about 5% by weight to about 9.5% by weight, for example, can be about 8.0% by weight to about 9.5% by weight. The "isocyanate group content" refers to the percentage of the weight of the isocyanate group (-NCO) that exists in the form of a free reactive group without undergoing a urethane reaction, in the total weight of the second composition. The NCO% of the second composition can be calculated based on the total weight of the second composition excluding the second curing agent and the second blowing agent described later. The isocyanate group content (NCO%) of the second composition can be designed by comprehensively adjusting the kind and content of the monomers used for the preparation of the second urethane-based prepolymer, the process conditions such as the temperature and pressure of the process for the preparation of the second urethane-based prepolymer, and the kind of additives used in the preparation of the second urethane-based prepolymer. In the case where the isocyanate group content satisfies the above range, it is advantageous to ensure the appropriate physical / mechanical properties of the polishing variable layer 101 prepared by curing the second composition, and to apply the polishing variable layer 101 in the state of being laminated with the polishing invariable layer 102, so that it is advantageous to impart excellent polishing performance to a polishing object by the first surface 11.

[0113] In an embodiment, the isocyanate group (-NCO) content in the first composition can be higher than the isocyanate group (-NCO) content in the second composition. That is, the isocyanate group (-NCO) content in the first composition can be higher than the isocyanate group (-NCO) content in the second composition, while the NCO% of the first composition and the NCO% of the second composition each satisfy the above range. For example, the ratio of the NCO% of the first composition to the NCO% of the second composition can be about 1:0.6 to about 1:0.9, for example, can be about 1:0.65 to about 1:0.85, for example, can be about 1:0.70 to about 1:0.80. When the NCO% of each of the first composition and the second composition satisfies the above size relationship, the properties of the laminated structure derived from the polishing invariable layer and the polishing variable layer can be advantageous to optimize the polishing performance of the polishing pad.

[0114] The second composition can further include a second curing agent and a second blowing agent. The second curing agent and the second blowing agent can each include the same compound as the first curing agent and the first blowing agent, or a different compound.

[0115] In an embodiment, the second curing agent can include a compound including one reactive group selected from the group consisting of an amino group, a hydroxyl group, and combinations thereof. The "reactive group" refers to a terminal group directly involved in a chemical reaction when the second curing agent reacts with a different kind of compound such as the second urethane-based prepolymer. That is, the second curing agent can include a compound including only an amino group as a reactive group in one molecule, or can include a compound including only a hydroxyl group as a reactive group in one molecule, or can include a compound including an amino group and a hydroxyl group as reactive groups in one molecule.

[0116] For example, the second curing agent can include one selected from the group consisting of 4,4'-methylenebis(2-chloroaniline) (MOCA), diethyltoluenediamine (DETDA), diaminodiphenylmethane, dimethylthio-toluene diamine (DMTDA), propanediol bis p-aminobenzoate, Methylene bis-methylanthranilate, diaminodiphenylsulfone, m-xylylenediamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, bis(4-amino-3-chlorophenyl)methane, triethanolamine, tripropanolamine, triisopropanolamine, and combinations thereof.

[0117] In one embodiment, the first curing agent can include a compound having a hydroxyl group as a reactive group in a molecule, and the second curing agent can include a compound having an amino group as a reactive group in a molecule. When each of the first and second curing agents is applied in this manner, it is possible to ensure excellent properties of the interface between the polishable variable layer and the polish-invariable layer, and the polishing layer as a laminate of the polishable variable layer and the polish-invariable layer can have more advantageous properties overall for optimizing polishing performance, and it is possible to achieve an environmental effect.

[0118] The content of the second curing agent in the entire second composition can be about 15% by weight to about 30% by weight, for example, can be about 18% by weight to about 27% by weight, for example, can be about 19% by weight to about 26% by weight, for example, can be about 20% by weight to about 26% by weight. When the second curing agent is applied at the content, it is possible to facilitate the polishable variable layer including the cured product of the second composition to ensure mechanical properties suitable for polishing and appropriate variability.

[0119] The molar ratio of isocyanate groups (-NCO) in the second composition to the reactive groups in the second curing agent (NCO: reactive group) can be about 1:0.80 to about 1:1.20, for example, can be about 1:0.90 to about 1:1.10, for example, can be about 1:0.90 to about 1:1.00, for example, can be about 1:0.90 or more and less than about 1:1.00. For example, in the case where the second curing agent includes a compound having an amino group as a reactive group in a molecule, the molar ratio of isocyanate groups (-NCO) in the second composition to the amino groups of the second curing agent (NCO: NH2) can satisfy the above range. When the molar ratio satisfies the above range, it is possible to form an appropriate crosslinked structure by chemically reacting the second urethane-based prepolymer and the second curing agent, as a result of which it is possible to facilitate the polishable variable layer to ensure physical / mechanical properties such as tensile strength and elongation at an appropriate level, thereby transmitting excellent polishing performance to the polished surface of the polishing target through the first surface.

[0120] The polishable variable layer 101 can be a porous structure including a plurality of pores 15. In the plurality of pores 15 located at the uppermost surface of the polishable variable layer 101, at least a portion of the inside thereof is exposed to the outside, and thus it is possible to impart a prescribed surface roughness to the first surface 11. Figure 2 The structural change of the first surface 11 in the polishing process of one embodiment is schematically shown. Specifically, Figure 2 is a schematic view showing the structural change of a portion of the plurality of pores 15 in which the inside thereof is exposed to the outside on the first surface 11 during the polishing process. Referring toFigure 2 The plurality of pores 15 are dispersed throughout the polishing variable layer 101, and thus contribute to the formation of surface roughness even when the uppermost surface is gradually removed during polishing using the first surface 11. However, with respect to the pores 15 that are exposed on the first surface 11, as the polishing process that is performed under a prescribed pressure condition is continued, the portions that correspond to the boundary between the first surface 11 and the pores 15 are pressed by the physical pressure and change in shape, and this phenomenon can affect the change in surface roughness of the first surface 11. At this time, the polishing layer includes the laminated structure of the polishing variable layer 101 and the polishing invariable layer 102, and thus has appropriate physical properties in the thickness direction, and thus can be advantageous in maintaining the surface state of the first surface 11 that is suitable for polishing for a long period of time.

[0121] In one embodiment, the plurality of pores 15 contained in the polishing variable layer 101 can have an average size of about 5 μm to about 50 μm, for example, about 5 μm to about 40 μm, for example, about 10 μm to about 40 μm, for example, about 10 μm to about 35 μm. When the plurality of pores satisfy the size, it can be advantageous for the first polishing variability index according to the following Equation 1 to satisfy the corresponding range, and thus it can be more advantageous for the realization of the polishing performance itself and the realization of uniform performance during the entire life of the polishing variable layer. The average size of the plurality of pores 15 is a two-dimensional value, and the size of the pores that are exposed on the outside of the surface of the polishing variable layer 101 is defined as the number average of the pore diameters measured from projections taken using a scanning electron microscope (SEM) or a transmission electron microscope (TEM) or the like, with the life introduction time point of the polishing variable layer 101 as a reference.

[0122] The second composition can include a second blowing agent. The second blowing agent, as a component for forming the pore structure in the polishing variable layer 101, can include one selected from the group consisting of a solid blowing agent, a gas blowing agent, a liquid blowing agent, and combinations thereof. In one embodiment, the second blowing agent can include a solid blowing agent, a gas blowing agent, or combinations thereof.

[0123] The solid foaming agent can include an expandable particle. The expandable particle, as a particle having a property that can be expanded by heat or pressure, the final size of the air hole can depend on the heat or pressure applied during the process of preparing the polishing variable layer 101, etc. The expandable particle can include a heat expanded particle, an unexpanded particle, or a combination thereof. The heat expanded particle, as a particle that is pre-expanded by heat, refers to a particle that has little or no change in size due to heat or pressure applied during the process of preparing the polishing variable layer. The unexpanded particle, as a particle that is not pre-expanded, refers to a particle that is expanded by heat or pressure applied during the process of preparing the polishing layer and the final size is determined.

[0124] The average particle size of the expandable particle can be about 5 μm to about 200 μm, for example, can be about 20 μm to about 50 μm, for example, can be about 21 μm to about 50 μm, for example, can be about 21 μm to about 40 μm. In the case of the expandable particle being a heat expanded particle, the average particle size refers to the average particle size of the heat expanded particle itself, and in the case of the expandable particle being an unexpanded particle, can refer to the average particle size of the particle after being expanded by heat or pressure.

[0125] The expandable particle can include: a skin of a resin material; and an expansion inducing component present in the inside surrounded by the skin.

[0126] For example, the skin can include a thermoplastic resin, which can be one or more selected from the group consisting of a vinylidene chloride-based copolymer, an acrylonitrile-based copolymer, a methacrylonitrile-based copolymer, and an acrylic copolymer.

[0127] The expansion inducing component can include one selected from the group consisting of a carbon hydride compound, a fluorochloride compound, a tetraalkylsilane compound, and a combination thereof.

[0128] Specifically, the carbon hydride compound can include one selected from the group consisting of ethane, ethylene, propane, propene, n-butane, isobutene, n-butene, isobutene, n-pentane, isopentane, neopentane, n-hexane, heptane, petroleum ether, and a combination thereof.

[0129] The fluorochlorinated compound can include one selected from the group consisting of trichlorofluoromethane (CCl3F), dichlorodifluoromethane (CCl2F2), chlorotrifluoromethane (CClF3), dichlorotetrafluoroethane (CClF2-CClF2), and combinations thereof.

[0130] The tetraalkylsilane compound can include one selected from the group consisting of tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, trimethyl-n-propylsilane, and combinations thereof.

[0131] The solid blowing agent can optionally include inorganic component-treated particles. For example, the solid blowing agent can include expandable particles treated with an inorganic component. In one embodiment, the solid blowing agent can include expandable particles treated with silicon dioxide (SiO2) particles. The inorganic component treatment of the solid blowing agent can prevent agglomeration between the particles. The chemical, electrical, and / or physical properties of the blowing agent surface of the inorganic component-treated solid blowing agent can be different from those of the non-inorganic component-treated solid blowing agent.

[0132] For example, the second blowing agent includes a solid blowing agent, and the amount of the solid blowing agent can be about 0.5 parts by weight to about 10 parts by weight, for example, about 1 part by weight to about 3 parts by weight, for example, about 1.3 parts by weight to about 2.7 parts by weight, for example, about 1.3 parts by weight to about 2.6 parts by weight, based on 100 parts by weight of the second urethane-based prepolymer.

[0133] The gas blowing agent can include an inert gas. The gas blowing agent can be added to serve as a pore-forming element during the reaction of the second urethane-based prepolymer with the second curing agent.

[0134] The kind of the inert gas is not particularly limited, as long as it is a gas that does not participate in the reaction between the second urethane-based prepolymer and the second curing agent. For example, the inert gas can include one selected from the group consisting of nitrogen (N2), argon (Ar), helium (He), and combinations thereof. Specifically, the inert gas can include nitrogen (N2) or argon (Ar).

[0135] In an embodiment, the second blowing agent can be formed of only the solid blowing agent.

[0136] In an embodiment, the solid blowing agent can include expanded particles, which can include the heat-expanded particles. For example, the expanded particles can consist of only the heat- expanded particles. In the case where the expanded particles do not include the unexpanded particles but consist of only the heat-expanded particles, although the variability of the pore structure is slightly decreased, the predictability is increased, thus being advantageous in realizing uniform pore properties in all regions of the polishing variable layer.

[0137] In an embodiment, the heat-expanded particles can be particles having an average particle diameter of about 5 μm to about 200 μm. The average particle diameter of the heat-expanded particles can be about 5 μm to about 100 μm, for example, about 10 μm to about 80 μm, for example, about 20 μm to about 70 μm, for example, about 20 μm to about 50 μm, for example, about 30 μm to about 70 μm, for example, about 25 μm to 45 μm, for example, about 40 μm to about 70 μm, for example, about 40 μm to about 60 μm. The average particle diameter is defined as D50 of the heat-expanded particles.

[0138] In an embodiment, the heat-expanded particles can have a density of about 30 kg / m 3 to about 80 kg / m 3 , for example, about 35 kg / m 3 to about 80 kg / m 3 , for example, about 35 kg / m 3 to about 75 kg / m 3 , for example, about 38 kg / m 3 to about 72 kg / m 3 , for example, about 40 kg / m 3 to about 75 kg / m 3 , for example, about 40 kg / m 3 to about 72 kg / m 3 .

[0139] In other embodiments, the second blowing agent can include a solid blowing agent and a gaseous blowing agent. Matters related to the solid blowing agent are as described above.

[0140] The second blowing agent can include the solid blowing agent and the gaseous blowing agent, and the gaseous blowing agent can include nitrogen.

[0141] The gaseous blowing agent can be injected using a prescribed injection line during mixing of the second urethane-based prepolymer, the solid blowing agent, and the second curing agent. The injection rate of the gaseous blowing agent can be about 0.8 L / min to about 2.0 L / min, for example, about 0.8 L / min to about 1.8 L / min, for example, about 0.8 L / min to about 1.7 L / min, for example, about 1.0 L / min to about 2.0 L / min, for example, about 1.0 L / min to about 1.8 L / min, for example, about 1.0 L / min to about 1.7 L / min.

[0142] The second composition for preparing the polishing variable layer can further include other additives such as a surfactant, a reaction rate adjusting agent, etc. The names of the "surfactant", "reaction rate adjusting agent", etc. are arbitrarily named based on the main role of the corresponding substance, and the function of each corresponding substance is not limited to the name of the substance.

[0143] The surfactant is not particularly limited as long as it is a substance that plays a role in preventing the phenomenon of pores gathering or overlapping, etc. For example, the surfactant can include a silicon-based polymer.

[0144] In the case where the second composition includes the surfactant, the content of the surfactant can be about 0.2 parts by weight to about 2 parts by weight, can be about 0.2 parts by weight to about 1.9 parts by weight, for example, about 0.2 parts by weight to about 1.8 parts by weight, for example, about 0.2 parts by weight to about 1.7 parts by weight, for example, about 0.2 parts by weight to about 1.6 parts by weight, for example, about 0.2 parts by weight to about 1.5 parts by weight, for example, about 0.5 parts by weight to 1.5 parts by weight, with respect to 100 parts by weight of the second urethane-based prepolymer. In the case where the content of the surfactant is within the above range, it is advantageous for pores caused by the gaseous blowing agent to be stably formed and maintained within the curing mold.

[0145] The reaction rate adjusting agent, which functions as an adjusting agent that plays a role in accelerating or delaying a reaction, can use a reaction accelerator, a reaction retarder, or both, according to the purpose.

[0146] The reaction rate adjusting agent can include a reaction accelerator. For example, the reaction accelerator can include one selected from the group consisting of a tertiary amine-based compound, an organic metal-based compound, and a combination thereof.

[0147] Specifically, the reaction rate adjusting agent can include one selected from the group consisting of triethylenediamine, dimethylethanolamine, tetramethylbutanediamine, 2-methyl-triethylenediamine, dimethylcyclohexylamine, triethylamine, triisopropanolamine, 1,4-diazabicyclo(2,2,2)octane, bis(2-methylaminoethyl)ether, trimethylaminoethanolamine, N,N,N,N,N"-pentamethyldiethylenetriamine, dimethylaminoethylamine, dimethylaminopropylamine, benzyldimethylamine, N-ethylmorpholine, N,N-dimethylaminoethylmorpholine, N,N-dimethylcyclohexylamine, 2-methyl-2-azanorbornane, dibutyl tin dilaurate, stannous octoate, dibutyl tin diacetate, dioctyl tin diacetate, dibutyl tin maleate, dibutyl tin diisooctoate, dibutyl tin dithiol, and combinations thereof. In an implementation, the reaction rate adjusting agent can include one selected from the group consisting of benzyldimethylamine, N,N-dimethylcyclohexylamine, triethylamine, and combinations thereof.

[0148] In a case where the second composition includes the reaction rate adjusting agent, the content of the reaction rate adjusting agent can be about 0.05 parts by weight to about 2 parts by weight, for example, about 0.05 parts by weight to about 1.8 parts by weight, for example, about 0.05 parts by weight to about 1.7 parts by weight, for example, about 0.05 parts by weight to about 1.6 parts by weight, for example, about 0.1 parts by weight to about 1.5 parts by weight, for example, about 0.1 parts by weight to about 0.3 parts by weight, for example, about 0.2 parts by weight to about 1.8 parts by weight, for example, about 0.2 parts by weight to about 1.7 parts by weight, for example, about 0.2 parts by weight to about 1.6 parts by weight, for example, about 0.2 parts by weight to about 1.5 parts by weight, for example, about 0.5 parts by weight to about 1 parts by weight, based on 100 parts by weight of the second urethane-based prepolymer. In a case where the reaction rate adjusting agent is used in the above range, it can be advantageous to adjust the curing reaction rate of the second composition so that the polishing variable layer has air pores and hardness of a desired size.

[0149] When the components and contents thereof of the polishing variable layer and the polishing invariant layer each satisfy the cases, the polishing layer of the laminate applying them can achieve a physical property precisely designed in the thickness direction. As a result, it can obtain an effect that the mechanical properties such as elasticity and rigidity of the polishing layer transmitted to the polished surface of a polishing object through the first surface are optimal in terms of polishing performance such as polishing rate, flatness, and defect prevention.

[0150] In an implementation, the first polishing variability index of the polishing variable layer according to the following 1st formula can be about 0.1 to about 11.0.

[0151] Formula 1:

[0152]

[0153] In the Formula 1, Ri is a surface roughness (Ra) of the first surface at a life introduction time point of the polishing variable layer, Rf is a surface roughness (Ra) of the first surface at a life end time point of the polishing variable layer, Ti is an overall thickness of the polishing pad at the life introduction time point of the polishing variable layer, and Tf is an overall thickness of the polishing pad at the life end time point of the polishing variable layer.

[0154] The polishing variable layer 101, as described above, has a prescribed life in providing a target level of polishing performance as a region in which physical and / or chemical properties change in a polishing process in which the polishing pad is applied. The life introduction time point of the polishing variable layer 101 refers to any time point from completion of preparation of the polishing variable layer or the polishing pad to before it is applied to a process. In addition, the life end time point of the polishing variable layer 101 refers to a time point at which the polishing variable layer 101 is unable to achieve polishing performance, and thus the polishing variable layer or the polishing pad as a whole needs to be replaced. For example, the life end time point can be defined as a time point at which a polishing rate of a polished surface of a polishing object changes by 20% with respect to an initial polishing rate within 1 hour after polishing is started. That is, the initial polishing rate is a polishing rate value measured within 1 hour after polishing is started with respect to the polished surface, and the life end time point can be defined as a time point at which a polishing rate with respect to the polished surface exhibits a polishing rate that increases by 20% or decreases by 20% with respect to the initial polishing rate.

[0155] The first polishing variability index takes the surface roughness (Ri, Rf) at each of the life introduction time point and the life end time point of the polishing variable layer 101 and the overall thickness (Ti, Tf) of the polishing pad 110 as constituent elements. The first polishing variability index according to the Formula 1 can serve as an index for indicating variability of the polishing variable layer 101. That is, when the value of the Formula 1 of the polishing variable layer is within the above range, i.e., about 0.1 to about 11.0, the polishing variable layer has variability corresponding thereto, and thus when the polishing variable layer is used as a part of the polishing layer 10, it is able to continuously and uniformly exhibit optimal structural characteristics in polishing efficiency during a life.

[0156] In an embodiment, the first polishing variability index can be about 0.1 to 11.0, for example, about 0.1 to about 9.0, for example, about 0.2 to about 9.0, for example, about 0.2 to about 8.5, for example, about 0.2 to about 8.0, for example, about 0.2 to about 7.5, for example, about 0.5 to about 7.5, for example, about 0.8 to about 7.5, for example, about 0.9 to about 7.5, for example, about 1.0 to about 6.0, for example, about 2.0 to 3.5.

[0157] The Ti, for example, can be about 800 μm to about 5000 μm, for example, about 1000 μm to about 4000 μm, for example, about 1000 μm to 3000 μm, for example, about 1500 μm to about 3000 μm, for example, about 1700 μm to about 2700 μm, for example, about 2000 μm to about 3500 μm, but is not limited thereto.

[0158] The Ri, for example, can be about 5 μm to about 15 μm, for example, about 5 μm to about 12 μm, for example, about 5 μm to 10 μm, but is not limited thereto.

[0159] In an embodiment, in the case where the first polishing variability index satisfies the above range while the Ti and the Ri satisfy the above ranges, respectively, it can be more advantageous in terms of achieving excellent polishing performance based on the structure characteristics of the polishing variability layer 101.

[0160] In an embodiment, the polishing variability layer 101 can include at least one groove 14 having a depth d1 less than or equal to the thickness D1 of the entire polishing variability layer 101 at the first surface 11. The groove 14 can function to adjust the flowability of a polishing liquid or a polishing slurry supplied onto the first surface 11 or to adjust the size of the direct contact area of the first surface 11 and a polished surface of a polishing object in a polishing process using the polishing pad, thereby achieving appropriate physical polishing characteristics.

[0161] For example, the polishing pad 110 can include a plurality of grooves 14 at the first surface 11. In an embodiment, the polishing pad 110 can have a substantially circular planar shape, and the plurality of grooves 14 can have a concentric circular structure disposed at regular intervals from the center to the end of the planar surface of the polishing pad 110. In another embodiment, the plurality of grooves 14 can have a radial structure continuously formed from the center to the end of the planar surface of the polishing pad 110. In still another embodiment, the plurality of grooves 14 can include both a concentric circular groove and a radial groove.

[0162] In the case where the first surface 11 includes at least one groove 14 in the polishing variable layer 101 which is a region from the first surface 11 to the detachable interface 13, a second polishing variability index (Polishing variability index) of the polishing variable layer 101 according to the following Formula 2 can be about 0.1 to about 3.5.

[0163] Formula 2:

[0164]

[0165] In the Formula 2, the Ri is a surface roughness (Ra) of the first surface at a life introduction time point of the polishing variable layer, the Rf is a surface roughness (Ra) of the first surface at a life end time point of the polishing variable layer, the Gi is a depth of the groove at the life introduction time point of the polishing variable layer, and the Gf is a depth of the groove at the life introduction time point of the polishing variable layer.

[0166] The explanation related to the life introduction time point and the life end time point of the polishing variable layer 101 is the same as the explanation above on the first polishing variability index according to the Formula 1. In the case where the second polishing variability index of the polishing variable layer 101 satisfies the above range, the polishing variable layer 101 can provide an optimal structure in terms of fluidity of a polishing liquid or a polishing slurry, and ensure a direct contact area on the first surface provided for a polished surface to be at an appropriate level, thus being able to more favorably ensure a polishing rate within a target range.

[0167] In an embodiment, the second polishing variability index can be about 0.1 to about 3.5, for example, can be about 0.1 to about 3.3, for example, can be about 0.1 to about 3.0, for example, can be about 0.1 to about 2.0, for example, can be about 0.3 to about 1.8, for example, can be about 0.5 to about 1.5, for example, can be about 0.5 to about 1.2, for example, can be about 0.5 to 1.0.

[0168] The Gi, for example, can be about 600 μm to about 900 μm, for example, can be about 650 μm to about 900 μm, for example, can be about 700 μm to about 900 μm, but is not limited thereto.

[0169] In an embodiment, in the case where the second polishing variability index satisfies the above range while the Ri and the Gi respectively satisfy the above range, it can be more favorable in terms of achieving polishing performance based on the structural characteristics of the polishing variable layer 101.

[0170] In an embodiment, the first and second polishing variability indices of the polishing variability layer 101 can satisfy the above ranges at the same time. In the case where the first and second polishing variability indices satisfy the above ranges, respectively, the polishing variability layer 101 as a part of the polishing layer 10 can have a structural feature that is optimal in terms of polishing efficiency, and in particular, can provide a structure that is optimal in terms of fluidity of a polishing liquid or a polishing slurry, and ensure that a direct contact area on the first surface provided for a surface to be polished is at an appropriate level, thus being more advantageous in ensuring a polishing rate within a target range. Further, it can be more advantageous in achieving a prescribed polishing performance during the entire life span to maintain the above advantages.

[0171] In the case where the first surface 11 includes at least one groove 14 having a depth that is less than or equal to the entire thickness of the polishing variability layer 101, the depth variation rate (%) of the groove 14 according to the following Equation 3 can be about 20% to about 100% for the polishing variability layer 101.

[0172] Equation 3:

[0173]

[0174] In Equation 3, Gi is a groove depth at a life introduction time point of the polishing variability layer 101, and Gf is a groove depth at an end-of-life time point of the polishing variability layer 101.

[0175] Matters related to the life introduction time point, the end-of-life time point of the polishing variability layer 101, and Gi and Gf are the same as described above with respect to the second polishing variability index.

[0176] In an embodiment, the groove depth variation rate according to Equation 3 can be about 20% to about 80%, for example, about 30% to 80%, for example, about 40% to about 80%, for example, about 40% to about 70%, for example, about 50% to about 70%.

[0177] Reference Figure 1In the polishing process, the depth dl of the groove 14 changes from the depth (Gi) at the life introduction time point to the depth (Gf) at the life end time point. Specifically, the depth dl of the groove 14 gradually becomes shallower according to the process in which the first surface 11 is removed by polishing performed by bringing the first surface 11 and the polished surface of the polishing object into physical contact with each other. At this time, the value of the third equation using the depth (Gi) of the groove at the life introduction time point and the depth (Gf) of the groove at the life end time point can satisfy the above range only on the basis that the elongation, tensile strength, hardness, and the like of the polishing variable layer 101 are maintained at appropriate levels. Specifically, if the physical properties of the polishing variable layer 101 do not satisfy the appropriate levels, there is a risk that, as the depth dl of the groove gradually becomes shallower, the influence of the change in the flowability of the polishing slurry or the like on the polishing performance becomes greater, thereby causing a sharp decline in the overall polishing performance. When the value of the third equation satisfies the above range, the polishing variable layer 101 of the implementation example can exhibit optimal physical properties corresponding thereto, and on the basis thereof, even in the case where the depth dl of the groove becomes shallower, it is possible to achieve excellent polishing performance throughout the polishing process by minimizing the influence on the polishing performance. In addition, it is possible to obtain the effect of extending the life of the polishing pad as the use time of the polishing variable layer 101 is maximized.

[0178] Referring to Figure 1 In the polishing process, the width wl of the groove 14 can have an influence on the size of the physical contact area of the first surface 11 and the polished surface of the polishing object. Therefore, it is possible to achieve the desired polishing performance by appropriately designing the width wl of the groove 14 according to the kind of the polishing object, the kind of the polishing liquid or the polishing slurry, the intended polishing performance, and the like. For example, the width wl of the groove 14 can be about 0.2 mm to about 1.0 mm, for example, about 0.3 mm to about 0.8 mm, for example, about 0.4 mm to about 0.7 mm, for example, about 0.4 mm to about 0.6 mm.

[0179] When the polishing variable layer 101 includes a plurality of grooves 14 in the first surface 11, it is also possible to help achieve the desired polishing performance by appropriately designing the pitch pl of the groove 14 defined by the interval between the two adjacent grooves 14 in the same context as the width wl of the groove 14. For example, the pitch pl of the groove 14 can be about 1.5 mm to about 5.0 mm, for example, about 1.5 mm to about 4.0 mm, for example, about 1.5 mm to about 3.0 mm.

[0180] Although the width w1 and the pitch p1 of the grooves are structural factors whose values are almost constant during the polishing process, for example, each of the ranges can be a value measured from a time point at which the life of the polishing variable layer 101 is introduced as a reference.

[0181] When the polishing variable layer 101 satisfies at least one of the first polishing variability index, the second polishing variability index, and the third polishing variability index, and the polishing invariable layer 102 is composed of the above-mentioned composition, the polishing layer 10 to which the layered structure is applied can be advantageous in simultaneously ensuring desired polishing performance in terms of polishing rate, polishing flatness, and defect prevention.

[0182] Figure 3 A cross section of the polishing pad 110 of an embodiment is schematically shown. Referring to Figure 3 The polishing pad 110 can further include a cushion layer 20 on a surface of the polishing layer 10. At this time, the second surface 12 of the polishing layer 10 can function as an attachment surface of the cushion layer 20.

[0183] The cushion layer 20 can impart impact absorbability to the polishing pad 110. In view of a semiconductor device manufacturing method to be described later, a polishing process is performed in a case where the first surface 11 as a polishing surface and a polished surface of a semiconductor substrate as a polishing target directly or indirectly contact each other, at this time, a prescribed pressurization condition can be applied according to a polishing purpose. The cushion layer 20 imparts appropriate elastic force in a thickness direction of the polishing pad 110, thereby minimizing occurrence of defects such as scratches on the polished surface in a polishing process performed under the pressurization condition, and can contribute to greatly improving polishing flatness of the polished surface.

[0184] The cushion layer 20 can include a nonwoven fabric or Suede, but is not limited thereto.

[0185] In an embodiment, the cushion layer 20 can include a nonwoven fabric. The "nonwoven fabric" refers to a three-dimensional network structure of un-woven fibers. Specifically, the cushion layer 20 can include a nonwoven fabric and a resin impregnated in the nonwoven fabric.

[0186] The nonwoven fabric, for example, can be a nonwoven fabric including fibers selected from the group consisting of polyester fibers, polyamide fibers, polypropylene fibers, polyethylene fibers, and combinations thereof.

[0187] The resin impregnated in the nonwoven fabric, for example, can include one selected from the group consisting of a polyurethane resin, a polybutadiene resin, a styrene-butadiene copolymer resin, a styrene-butadiene-styrene copolymer resin, an acrylonitrile-butadiene copolymer resin, a styrene-ethylene-butadiene-styrene copolymer resin, a silicone rubber resin, a polyester-based elastomer resin, a polyamide-based elastomer resin, and combinations thereof.

[0188] In an embodiment, the cushion layer 20 can include a nonwoven fabric including fibers of a polyester fiber, wherein a resin including a polyurethane resin is impregnated in the polyester fiber. When a resin and a nonwoven fabric of such a material are applied as the cushion layer 20, the laminated combination of the cushion layer 20 and the polishing layer 10 to which the polishing variable layer 101 and the polishing invariable layer 102 are applied can be more advantageous in achieving a desired polishing performance.

[0189] In an embodiment, the thickness of the cushion layer 20 can be about 0.5 mm to about 2.5 mm, for example, about 0.8 mm to about 2.5 mm, for example, about 1.0 mm to about 2.5 mm, for example, about 1.0 mm to about 2.0 mm, for example, about 1.2 mm to about 1.8 mm.

[0190] Referring to Figure 3 The polishing pad 110 of an embodiment can further include a first adhesive layer 30 for attaching the polishing layer 10 and the cushion layer 20. The first adhesive layer 30, for example, can include a heat sealing adhesive. Specifically, the first adhesive layer 30 can be one selected from the group consisting of a urethane-based adhesive, a silicone-based adhesive, an acrylic-based adhesive, and combinations thereof, but is not limited thereto.

[0191] Referring to Figure 3 The polishing pad 110 can further include a second adhesive layer 40 for attaching a flat plate. The second adhesive layer 40, as an interlayer for attaching the polishing pad 110 and a flat plate of a polishing apparatus, for example, can be derived from a pressure sensitive adhesive (PSA), but is not limited thereto.

[0192] In an embodiment, the polishing pad 110 can have a compression rate of about 0.3% to about 1.8%, for example, about 0.3% to 1.6%, for example, 0.3% to 1.4%, for example, about 0.5% to 1.4%, for example, about 0.7% to about 1.4%, for example, greater than about 0.9% and about 1.2% or less. The polishing pad 110 can achieve the compression rate in the above range by the above-described structure designed to be subdivided in the thickness direction, and can exert a corresponding elastic force to the polished surface through the first surface 11, thereby maximizing the defect prevention performance.

[0193] Hereinafter, a method of manufacturing the polishing pad 110 will be described.

[0194] The polishing pad 110 can be manufactured by a manufacturing method including a step of manufacturing a polishing layer 10 including a first surface 11 as a polishing surface, a second surface 12 as an opposite surface of the first surface 11, and at least one separable interface 13 between the first surface 11 and the second surface 12, wherein the step of manufacturing the polishing layer 10 includes a step of manufacturing at least one polishing variable layer 101 as a region from the first surface 11 to the separable interface 13, a step of manufacturing at least one polishing invariable layer 102 as a region from the separable interface 13 to the second surface 12, and a step of laminating the polishing variable layer 101 and the polishing invariable layer 102 with the separable interface 13 as a lamination interface, wherein the step of manufacturing the polishing invariable layer 102 includes a step of reacting a first isocyanate component and a first alcohol component including a first polyol having a hydroxyl value of 200 mgKOH / g to 900 mgKOH / g, thereby manufacturing a first urethane-based prepolymer, and a step of curing a first composition including the first urethane-based prepolymer.

[0195] Matters related to each of the polishing variable layer 101, the polishing invariable layer 102, and the separable interface 103 are the same as described above with respect to the polishing pad 110. In addition, with respect to each matter related to the first polyol, the first alcohol component, the first isocyanate component, the first urethane-based prepolymer, and the first composition, all matters and technical advantages thereof described above with respect to the polishing pad 110 can be fully applicable to the manufacturing method of the polishing pad.

[0196] The step of laminating the polishing variable layer 101 and the polishing invariable layer 102 can be a step of laminating using double-sided tape. The double-sided tape is not particularly limited as long as it can adhere to each other, and for example, can include one selected from the group consisting of an acrylic adhesive, a urethane adhesive, and a combination thereof. Thereby, the laminated interface of the polishing variable layer 101 and the polishing invariable layer 102 can function as the separable interface 13.

[0197] In an embodiment, the step of preparing the polishing invariable layer 102 can further include a step of preparing the first polyol from a waste of a polishing pad. The first polyol is not particularly limited as long as it satisfies the range of the hydroxyl value, and for example, in a case where the first polyol is derived from the waste of the polishing pad, since the first polyol is derived from the waste of the polishing pad used for the same purpose, it can be easier to achieve a property in accordance with a technical purpose and can achieve a technical effect that contributes to environmental protection. As described above, the "polishing pad waste" can refer to a polishing pad discarded after use in a polishing process or a byproduct discarded during a preparation process of the polishing pad.

[0198] For example, the step of preparing the first polyol from the waste of the polishing pad can include a step of obtaining a pulverized product by pulverizing the waste of the polishing pad, and a step of obtaining the first polyol by hydrolyzing the pulverized product.

[0199] The average particle diameter of the pulverized product can be about 20 μm to about 3.0 mm, for example, about 50 μm to about 2.0 mm, for example, about 100 μm to about 2.0 mm, for example, about 500 μm to about 2.0 mm. When the pulverized product is pulverized to such a size, it can be advantageous to obtain a polyol having a target level of a hydroxyl value and a molecular weight with a high yield in a subsequent hydrolysis process. The average particle diameter of the pulverized product, which is a number average of diameters measured in cross section, can be obtained from a two-dimensional projection of the particles. The method of obtaining the projection is not particularly limited, and for example, a scanning electron microscope (SEM) or a transmission electron microscope (TEM) can be used.

[0200] The step of obtaining the first polyol by hydrolyzing the pulverized material can include the steps of treating the pulverized material with a hydrolysis composition including at least one alcohol; and reacting the pulverized material treated with the hydrolysis composition under temperature conditions of 130°C to 200°C. When the pulverized material is treated under such conditions, the polymer chains constituting the polishing pad waste are decomposed in a prescribed unit, and thus the first polyol having at least two terminal hydroxyl groups and having a desired prescribed hydroxyl value can be prepared.

[0201] In an embodiment, the weight ratio of the pulverized material to the hydrolysis composition can be about 1 : 0.5 to about 1 : 6, for example, about 1 : 0.8 to about 1 : 6, for example, about 1 : 0.8 to about 1 : 5, for example, about 1 : 1 to about 1 : 4, for example, about 1 : 1 to 1 : 3.

[0202] In an embodiment, for the step of reacting the pulverized material treated with the hydrolysis composition under temperature conditions of 130°C to 200°C, the reaction time can be adjusted according to the amount of the pulverized material, but for example, about 1 hour to about 8 hours can be performed.

[0203] The temperature at which the pulverized material treated with the hydrolysis composition is reacted can be, for example, about 130°C to about 200°C, for example, about 140°C to about 200°C, for example, about 150°C to about 200°C, for example, about 160°C to about 200°C, for example, about 160°C to about 190°C.

[0204] In an embodiment, the hydrolysis composition can include diethylene glycol (DEG).

[0205] In an embodiment, the step of obtaining the first polyol can further include a step of adding a catalyst as needed.

[0206] The first polyol having a hydroxyl value of about 200 mgKOH / g to about 900 mgKOH / g can be obtained by processing the polishing pad waste in the above-described manner. For example, the first polyol can have a hydroxyl value of about 300 mgKOH / g to about 900 mgKOH / g, for example, about 300 mgKOH / g to about 800 mgKOH / g, for example, about 300 mgKOH / g to about 750 mgKOH / g, for example, about 450 mgKOH / g to about 650 mgKOH / g. In the case where a polyol having the hydroxyl value is used as the first polyol, the physical and / or mechanical properties of the polishing invariable layer derived from the first polyol can be advantageous in achieving polishing performance in the case of use with the polishing variable layer. In addition, the first polyol as a recycled polyol can be more advantageously obtained from the polishing pad waste by processing.

[0207] The first urethane-based prepolymer can be prepared by reacting the first isocyanate component and the first alcohol component containing the first polyol. As to matters related to each of the first alcohol component and the first isocyanate component, matters and technical advantages thereof related thereto in the above description regarding the polishing pad can be applied to the method of preparing the polishing pad. The step of preparing the first urethane-based prepolymer can be performed at about 60°C to about 100°C, for example, about 60°C to about 90°C, for example, about 70°C to about 90°C, for example, about 70°C to about 80°C. When the first alcohol component and the first isocyanate component are reacted within the temperature range, it can be more advantageous to obtain a first urethane-based prepolymer satisfying an isocyanate group content (NCO%) enabling optimal physical / mechanical properties in a subsequent curing process while having a molecular chain of an appropriate length.

[0208] The isocyanate group content (NCO%) of the first composition can be about 8% by weight to 20% by weight, for example, about 8% by weight to about 18% by weight, for example, about 8% by weight to about 15% by weight, for example, about 9% by weight to about 15% by weight, for example, about 10% by weight to about 15% by weight, for example, more than about 10% by weight and about 15% by weight or less. The "isocyanate group content (NCO%)" of the first composition refers to the percentage by weight of the isocyanate group (-NCO) present in the form of a free reactive group without reaction in the composition. The NCO% of the first composition can be calculated based on the total weight of the first composition excluding the first curing agent and the first blowing agent described later.

[0209] The viscosity of the first composition can be about 100 cps to about 1000 cps, for example, about 200 cps to about 800 cps, for example, about 200 cps to about 600 cps, for example, about 200 cps to about 550 cps, for example, about 300 cps to about 500 cps at about 80°C. When the viscosity range is satisfied, the first composition can exhibit proper fluidity in the subsequent curing process, thereby facilitating the preparation of a cured product having no voids and being uniform.

[0210] The step of preparing the polishing invariable layer can further include a step of mixing one selected from the group consisting of a first curing agent, a first blowing agent, and a combination thereof in the first composition containing the first urethane-based prepolymer. For each matter related to the first curing agent and the first blowing agent, the specific matters corresponding thereto in the above description related to the polishing pad and the technical advantages thereof can be applied to the method of preparing the polishing pad.

[0211] In this case, in an embodiment, the first blowing agent includes the solid blowing agent, and the step of preparing the polishing invariable layer can further include a step of preparing a 1-1 composition by mixing the solid blowing agent in the first composition, and a step of preparing a 1-2 composition by mixing the first curing agent in the 1-1 composition. As described above, in the case of mixing the solid blowing agent first and then mixing the curing agent, the first composition is easily prepared to have a viscosity suitable for curing, and it is possible to finally secure a uniform pore structure by improving the dispersibility of the solid blowing agent.

[0212] For example, the viscosity of the 1-1 composition can be about 1000 cps to about 2000 cps, for example, about 1000 cps to about 1800 cps, for example, about 1000 cps to about 1600 cps, for example, about 1000 cps to about 1500 cps at about 80°C. When the viscosity range is satisfied, it is more efficient in adjusting the final density of the second composition within the above range by mixing additional ingredients.

[0213] In an embodiment, the first blowing agent includes a gas blowing agent, and the step of preparing the polishing invariable layer can further include a step of injecting the gas blowing agent into the 1-2 composition. At this time, the gas blowing agent can be injected together with the first curing agent, or sequentially one after another. The gas blowing agent can be selectively used as needed in order to adjust the final pore structure after the solid blowing agent is injected.

[0214] When the gas blowing agent is injected in the first composition, the injection rate of the gas blowing agent can be, for example, about 0.8 L / min to about 2.0 L / min, for example, about 0.8 L / min to about 1.8 L / min, for example, about 0.8 L / min to about 1.7 L / min, for example, about 1.0 L / min to about 2.0 L / min, for example, about 1.0 L / min to about 1.8 L / min, for example, about 1.0 L / min to about 1.7 L / min.

[0215] In an embodiment, the step of curing the first composition can include the steps of: preparing a mold preheated to a first temperature; injecting the first composition into the preheated mold and curing; and post-curing the first composition at a second temperature higher than the first temperature.

[0216] In an embodiment, the temperature difference (T2-T1) between the first temperature (T1) and the second temperature (T2) can be about 10°C to about 40°C, for example, about 10°C to about 35°C, for example, about 15°C to about 35°C.

[0217] In an embodiment, the first temperature can be about 60°C to about 100°C, for example, about 65°C to about 95°C, for example, about 70°C to about 90°C. In an embodiment, the second temperature can be about 100°C to about 130°C, for example, about 100°C to 125°C, for example, about 100°C to about 120°C.

[0218] In curing the first composition, as described above, in the case of applying a multi-stage temperature condition, it can be more advantageous to ensure proper mechanical properties in terms of the compatibility of the polishing invariable layer 102 prepared by the above method with the polishing variable layer 101.

[0219] In the step of curing the first composition, the step of injecting the first composition into the preheated mold and curing can be performed for about 5 minutes to about 60 minutes, for example, about 5 minutes to about 40 minutes, for example, about 5 minutes to about 30 minutes, for example, about 5 minutes to about 25 minutes.

[0220] The step of post-curing the cured first composition at a second temperature higher than the first temperature can be performed for about 5 hours to about 30 hours, for example, about 5 hours to about 25 hours, for example, about 5 hours to about 20 hours, for example, about 5 hours to about 15 hours, for example, about 8 hours to about 12 hours.

[0221] In the step of curing the first composition, the mold can be a mold having a width of about 500 mm to about 1500 mm, a length of about 500 mm to about 1500 mm, and a height of about 1 mm to about 1000 mm. In one embodiment, the height of the mold can be about 1 mm to about 10 mm. In another embodiment, the height of the mold can be about 300 mm to about 1000 mm.

[0222] The step of preparing the polishing invariant layer can further include a step of processing the cured product of the first composition to a desired thickness. In the step of curing the first composition, a plurality of polishing invariant layers can be prepared from one cured product according to the height of the mold, or a single polishing invariant layer can be prepared from one cured product. For example, in the case where the height of the mold is about 1 mm to about 10 mm, one polishing invariant layer can be prepared for one cured product of the first composition discharged from the mold. In this case, the step of processing the cured product of the first composition to a desired thickness can be a line turning step for the purpose of surface treatment. For example, in the case where the height of the mold is about 300 mm to about 1000 mm, a plurality of polishing invariant layers can be prepared for one cured product of the first composition discharged from the mold. In this case, the step of processing the cured product of the first composition to a desired thickness can be a cutting step for the purpose of dividing the plurality of polishing invariant layers.

[0223] The method of preparing the polishing pad 110 includes a step of preparing the polishing variant layer 101, and the step of preparing the polishing variant layer 101 can include steps of preparing a second composition containing a second urethane-based prepolymer, and curing the second composition. Matters related to the second composition and the second urethane-based prepolymer are the same as described above with respect to the polishing pad 110.

[0224] In an embodiment, the step of preparing the second composition can further include a step of preparing the second urethane-based prepolymer by reacting a second isocyanate component and a second alcohol component including a second polyol having a hydroxyl value of 50 mgKOH / g or more and less than 200 mgKOH / g. For matters related to each of the second polyol, the second alcohol component, and the second isocyanate component, the specific examples and technical advantages thereof related thereto in the above description of the polishing pad can be fully applicable to the method of preparing the polishing pad. The step of preparing the second urethane-based prepolymer can be performed at about 60°C to about 100°C, for example, about 60°C to about 90°C, for example, about 70°C to about 90°C, for example, about 75°C to about 86°C. When the second isocyanate component and the second alcohol component are reacted within the temperature range, it can be more advantageous to obtain the second urethane-based prepolymer satisfying the isocyanate-based content (NCO %) for curing in a subsequent curing process while having a molecular chain of an appropriate length, thereby enabling optimal physical / mechanical properties.

[0225] The second composition including the second urethane-based prepolymer can have a viscosity of about 100 cps to about 1000 cps, for example, about 200 cps to about 800 cps, for example, about 200 cps to about 600 cps, for example, about 200 cps to about 550 cps, for example, about 300 cps to about 500 cps at about 80°C. When the viscosity range is satisfied, the preparation efficiency of the polishing variable layer 101 is improved in a subsequent process, and curing can be facilitated to ensure appropriate hardness and density.

[0226] The step of preparing the second composition can further include a step of mixing the second curing agent and the second blowing agent in the second composition including the second urethane-based prepolymer. Matters related to the second curing agent and the second blowing agent are the same as described above with respect to the polishing pad 110. The second curing agent and the second blowing agent can be simultaneously introduced or sequentially introduced.

[0227] In the case where the second blowing agent includes a solid blowing agent, the step of preparing the second composition can include a step of preparing a 2-1 composition by mixing the second urethane-based prepolymer and the solid blowing agent, and a step of preparing a 2-2 composition by mixing the 2-1 composition and the second curing agent.

[0228] The viscosity of the 2-1 composition can be about 1000 cps to about 2000 cps at about 80°C, for example, can be about 1000 cps to about 1800 cps, for example, can be about 1000 cps to about 1600 cps, for example, can be about 1000 cps to about 1500 cps. When the viscosity range is satisfied, it can be more effective in adjusting the final density of the second composition within the above range by mixing additional ingredients.

[0229] In the case where the second blowing agent includes a gas blowing agent, the step of preparing the second composition can include a step of injecting the gas blowing agent into the 2-2 composition.

[0230] For example, the injection speed of the gas blowing agent is about 0.8 L / min to about 2.0 L / min, for example, can be about 0.8 L / min to about 1.8 L / min, for example, can be about 0.8 L / min to about 1.7 L / min, for example, can be about 1.0 L / min to about 2.0 L / min, for example, can be about 1.0 L / min to about 1.8 L / min, for example, can be about 1.0 L / min to about 1.7 L / min.

[0231] In an embodiment, the step of curing the second composition can include a step of preparing a mold preheated to a first temperature; curing the second composition by injecting the second composition into the preheated mold; and post-curing the cured second composition at a second temperature higher than the first temperature.

[0232] In an embodiment, the temperature difference (T2-T1) between the first temperature (T1) and the second temperature (T2) can be about 10°C to about 40°C, for example, can be about 10°C to about 35°C, for example, can be about 15°C to about 35°C.

[0233] In an embodiment, the first temperature can be about 60°C to about 100°C, for example, can be about 65°C to about 95°C, for example, can be about 70°C to about 90°C. In an embodiment, the second temperature can be about 100°C to about 130°C, for example, can be about 100°C to 125°C, for example, can be about 100°C to about 120°C.

[0234] In the curing of the second composition, as described above, in the case where a multi-stage temperature condition is applied, the polishing variable layer 101 prepared by the above method can be more advantageous in securing desired physical / mechanical properties such as hardness, tensile strength, and elongation.

[0235] The step of post-curing the cured second composition at a second temperature higher than the first temperature can be performed for about 5 hours to about 30 hours, for example, about 5 hours to about 25 hours, for example, about 10 hours to about 30 hours, for example, about 10 hours to about 25 hours, for example, about 12 hours to about 24 hours, for example, about 15 hours to about 24 hours.

[0236] The step of post-curing the cured second composition at a second temperature higher than the first temperature can be performed for about 5 hours to about 30 hours, for example, about 5 hours to about 25 hours, for example, about 10 hours to about 30 hours, for example, about 10 hours to about 25 hours, for example, about 12 hours to about 24 hours, for example, about 15 hours to about 24 hours.

[0237] The method of manufacturing the polishing pad 110 can further include a step of processing the first surface 11.

[0238] The step of processing the first surface 11 can include at least one of a first step of forming a groove on the first surface 11, a second step of turning processing the first surface 11, and a third step of roughening processing the first surface 11.

[0239] In the first step, the groove can include at least one of a concentric circular groove formed at a prescribed interval from the center to the edge of the polishing variable layer 101 on the first surface 11 and a radial groove continuously formed from the center to the edge of the polishing variable layer 101 on the first surface 11.

[0240] In the second step, the turning processing can be performed in such a manner that a cutting tool is used to cut the first surface 11 at a prescribed thickness.

[0241] In the third step, the roughening processing can be performed in such a manner that a sanding roller is used to process the first surface 11.

[0242] As described above, when the laminate of the polishing variable layer 101 and the polishing invariable layer 102 is applied to the polishing layer 10, it is possible to ensure the advantage that a design capable of achieving precise and diverse properties in the thickness direction of the polishing layer 10 can be implemented, and it is possible to provide excellent polishing performance to the polished surface of a polishing object through the first surface 11 of the polishing variable layer 101.

[0243] The method of manufacturing the polishing pad 110 can further include a step of laminating a buffer layer 20 on the second surface 12 of the polishing layer 10. Matters related to the buffer layer 20 are the same as described above with respect to the polishing pad 110.

[0244] In one embodiment, the step of laminating the buffer layer 20 can include the steps of: applying a hot melt adhesive on the second surface 12; applying a hot melt adhesive on a surface of the buffer layer 20; laminating the second surface 12 and the buffer layer 20 with the respective surfaces on which the hot melt adhesive is applied in contact with each other; and performing fusion under pressure or heat.

[0245] The hot melt adhesive is not particularly limited, and for example, can include one selected from the group consisting of urethane-based adhesives, silicon-based adhesives, acrylic-based adhesives, and combinations thereof.

[0246] Referring to Figure 3 In the process of laminating the buffer layer 20, a first adhesive layer 30 can be formed on the second surface 12.

[0247] In one embodiment, the method of manufacturing the polishing pad 110 can further include a step of forming a second adhesive layer 40 on a surface of the buffer layer 20. The second adhesive layer 40, as a structure for attaching the polishing pad 110 to a flat plate of a polishing device, for example, can originate from a pressure sensitive adhesive (PSA), but is not limited thereto.

[0248] Specifically, in one embodiment, the step of forming the second adhesive layer 40 can include the steps of: applying a pressure sensitive adhesive on a surface of the buffer layer 20 opposite to the surface to which the second surface 12 is attached; and drying the pressure sensitive adhesive.

[0249] In another embodiment, the step of forming the second adhesive layer 40 can include the steps of: preparing an adhesive film including a pressure sensitive adhesive; and attaching the adhesive film to a surface of the buffer layer 20 opposite to the surface to which the second surface 12 is attached.

[0250] The polishing pad 110 can be manufactured by the above-described manufacturing method, and specifically, a laminated structure based on the polishing variable layer 101 and the polishing invariant layer 102 can be obtained, and a polishing layer having physical properties accurately designed in a thickness direction.

[0251] In another embodiment of the present application, there is provided a method for manufacturing a semiconductor device, including the steps of: providing a polishing pad on a flat plate, the polishing pad including a polishing layer having a polishing surface, and disposing a polishing surface of a polishing object in contact with the polishing surface, and then polishing the polishing object under a pressurized condition while rotating the polishing pad and the polishing object relative to each other; the polishing layer including: a polishing variable layer including the polishing surface, and a polishing invariable layer disposed on the opposite side of the polishing surface of the polishing variable layer; the polishing invariable layer including a cured product of a first composition including a first urethane-based prepolymer, the first urethane-based prepolymer being a reaction product of a first alcohol component and a first isocyanate component, the first alcohol component including a first polyol having a hydroxyl value of 200 mgKOH / g to 900 mgKOH / g.

[0252] In the method for manufacturing a semiconductor device, the above-described specific matters related to the polishing pad and technical advantages thereof are applicable to the following description related to the method for manufacturing a semiconductor device in terms of matters related to all substructures of the polishing pad.

[0253] In the method for manufacturing a semiconductor device using the polishing pad 110, a high-quality semiconductor device can be produced under optimal physical property conditions achieved by the structure and composition characteristics of the polishing pad 110.

[0254] Specifically, as the polishing pad 110, a polishing layer 10 including a laminated structure of the polishing variable layer 101 and the polishing invariable layer 102 is used, and a cured product of a first composition including a first urethane-based prepolymer is used as the polishing invariable layer, in which the first urethane-based prepolymer is a layer that is a reaction product of a first isocyanate component and a first alcohol component including a first polyol having a hydroxyl value of 200 mgKOH / g to 900 mgKOH / g, so that the method for manufacturing a semiconductor device using the polishing pad 110 can ensure excellent polishing results in terms of polishing flatness, polishing rate, and defect prevention, and achieve an environmental effect.

[0255] All matters related to the first urethane-based prepolymer and substructures thereof are the same as described above with respect to the polishing pad 110.

[0256] Figure 4 is a schematic view of the method for manufacturing a semiconductor device according to an embodiment. Referring to Figure 4 The polishing pad 110 can be provided on the flat plate 120. When the polishing pad 110 is provided on the flat plate 120, the first surface 11 of the polishing layer 10 becomes an uppermost end surface, and the second surface 12 can be disposed toward the flat plate 120 side.

[0257] In one embodiment, the polishing pad 110 and the flat plate 120 can be attached with an adhesive layer as an intermediary. For example, the adhesive layer can be derived from a pressure sensitive adhesive (PSA), but is not limited thereto.

[0258] The method of manufacturing the semiconductor device includes the steps of disposing the polished surface of the polishing object 130 in contact with the first surface 11, and then polishing the polishing object 130 under a pressurized condition while rotating the polishing pad 110 and the polishing object 130 relative to each other.

[0259] In one embodiment, the polishing object 130 can be a semiconductor substrate. For example, the polished surface of the semiconductor substrate can include a metal oxide film, a metal nitride film, or a metal film. In one embodiment, the polished surface can be a single film composed of one of a metal oxide, a metal nitride, and a metal. In another embodiment, the polished surface can be a composite film containing at least two of a metal oxide, a metal nitride, and a metal.

[0260] In each of the metal oxide film, the metal nitride film, and the metal film, the metal component can be one selected from the group consisting of silicon (Si), copper (Cu), tantalum (Ta), titanium (Ti), tungsten (W), and combinations thereof.

[0261] In one embodiment, the polished surface of the polishing object 130 can be a single film formed of a silicon oxide film. In another embodiment, the polished surface of the polishing object 130 can be a single film formed of a copper film. In yet another embodiment, the polished surface of the polishing object 130 can be a composite film containing a silicon oxide film. In yet another embodiment, the polished surface of the polishing object 130 can be a composite film containing a copper film.

[0262] The load pressure with which the polished surface of the polishing object 130 is pressed against the first surface 11 can be appropriately designed according to the kind and purpose of the polished surface, but for example, can be about 0.01 psi to about 20 psi, for example, about 0.1 psi to about 15 psi. As described above, the polishing pad 110 includes a layered structure in which the polishing variable layer 101 and the polishing invariant layer 102 are applied, thereby including a polishing layer having a structure feature subdivided in the thickness direction, and appropriate rigidity and elasticity in accordance with various purposes can be provided to the polished surface under the pressurized condition in the above range by this structure feature. As a result, in the case where the polishing object 130 includes a semiconductor substrate, the final polishing result of the semiconductor substrate can be greatly improved in terms of polishing flatness and defect prevention.

[0263] The polishing pad 110 and the polishing object 130 can be rotated relative to each other with the first surface 11 and the polished surface of the polishing object 130 in contact with each other. At this time, the direction of rotation of the polishing object 130 and the direction of rotation of the polishing pad 110 can be the same direction or the opposite direction. The first surface 11 and the polished surface of the polishing object 130 can be in direct contact or in indirect contact with a medium such as a component in a slurry having fluidity. The rotation speed of the polishing object 130 and the polishing pad 110 can be selected in the range of about 10 rpm to about 500 rpm, for example, about 30 rpm to about 200 rpm, but is not limited thereto. As described above, the polishing pad 110 can provide polishing performance according to various purposes by the structure features subdivided in the thickness direction. When the polishing object 130 and the polishing pad 110 are rotated at the rotation speed in the above range while being in contact with each other, the behavior under the centrifugal force and the frictional force is associated with the structure features of the polishing pad 110, and thus the polishing result excellent in polishing flatness and defect prevention for the polished surface can be calculated.

[0264] In the method of manufacturing the semiconductor device, the first polishing variability index of the polishing variable layer 101 according to the first formula can be about 0.1 to about 11.0. In an implementation example, the first polishing variability index, for example, can be about 0.1 to about 9.0, for example, can be about 0.2 to about 9.0, for example, can be about 0.2 to about 8.5, for example, can be about 0.2 to about 8.0, for example, can be about 0.2 to about 7.5, for example, can be about 0.5 to about 7.5, for example, can be about 0.8 to about 7.5, for example, can be about 0.9 to about 7.5, for example, can be about 1.0 to about 6.0, for example, can be about 2.0 to 3.5.

[0265] The polishing variable layer 101 has a prescribed lifetime in providing polishing performance at a purpose level as a region in which the physical and / or chemical properties change in the polishing process of the semiconductor device manufacturing method using the polishing pad 110. The lifetime introduction point of the polishing variable layer 101 refers to any point in time from the completion of the preparation of the polishing variable layer 101 itself or the polishing pad 110 to before it is used in the process. In addition, the lifetime end point of the polishing variable layer 101 refers to the point in time at which the polishing variable layer 101 cannot achieve polishing performance, and thus the polishing variable layer 101 itself or the entire polishing pad 110 needs to be replaced.

[0266] The first polishing variability index according to the first formula is an index indicating variability of the polishing variability layer 101, wherein the first formula takes the surface roughness (Ri, Rf) at each of the life introduction time point and the life end time point of the polishing variability layer 101 and the overall thickness (Ti, Tf) of the polishing pad 110 as constituent factors, and when the value of the first formula satisfies the above range so that the polishing variability layer 101 has variability corresponding thereto, the polishing variability layer 101 as a part of the polishing layer 10 can have structural characteristics optimal in polishing efficiency while at the same time can be more advantageous in realizing constant polishing performance during the overall life thereof, thereby mass-producing semiconductor devices of the same quality.

[0267] The Ti, for example, can be about 800 μm to about 5000 μm, for example, can be about 1000 μm to about 4000 μm, for example, can be about 1000 μm to 3000 μm, for example, can be about 1500 μm to about 3000 μm, for example, can be about 1700 μm to about 2700 μm, for example, can be about 2000 μmm to about 3500 μm, but is not limited thereto.

[0268] The Ri, for example, can be about 5 μm to about 15 μm, for example, can be about 5 μm to about 12 μm, for example, can be about 5 μm to 10 μm, but is not limited thereto.

[0269] In an implementation example, in the case where the first polishing variability index satisfies the above range while the Ti and the Ri each satisfy the above range, it can be more advantageous in realizing structural characteristics and polishing performance of the polishing variability layer 101.

[0270] In an implementation example, the polishing pad 110 can include at least one groove 14 having a depth d1 less than or equal to the thickness D1 of the entire polishing variability layer 101 on the first surface 11. The groove 14 can function to realize appropriate physical polishing characteristics by adjusting the flowability of a polishing liquid or a polishing slurry supplied onto the first surface 11 or adjusting the size of the direct contact area of the first surface 11 with a polished surface of a polishing object in a polishing process using the polishing pad 110.

[0271] For example, the polishing pad 110 can include a plurality of grooves 14 on the first surface 11. In one embodiment, the planar shape of the polishing pad 110 can be substantially circular, and the plurality of grooves 14 can have a concentric circular structure disposed at regular intervals from the center of the planar surface of the polishing pad 110 to the end. In another embodiment, the plurality of grooves 14 can have a radial structure continuously formed from the center of the planar surface of the polishing pad 110 to the end. In yet another embodiment, the plurality of grooves 14 can include both concentric circular grooves and radial grooves.

[0272] In the polishing variable layer 101 that is a region from the first surface 11 to the detachable interface 13, the first surface 11 can include at least one groove 14. At this time, in the method of manufacturing a semiconductor device, the second polishing variability index of the polishing variable layer 101 according to the second formula can be about 0.1 to about 3.5, for example, about 0.1 to about 3.3, for example, about 0.1 to about 3.0, for example, about 0.1 to about 2.0, for example, about 0.3 to about 1.8, for example, about 0.5 to about 1.5, for example, about 0.5 to about 1.2, for example, about 0.5 to 1.0.

[0273] The explanation related to the life introduction time point and the life end time point of the polishing variable layer 101 is the same as the above explanation on the first polishing variability index according to the first formula. In the case where the second polishing variability index of the polishing variable layer 101 satisfies the above range, the polishing variable layer 101 can provide an optimal structure in terms of the fluidity of the polishing liquid or the polishing slurry, and ensure the direct contact area provided to the polished surface to be at an appropriate level, thereby making it possible to more favorably ensure the polishing rate within the intended range.

[0274] The Gi, for example, can be about 600 μm to about 900 μm, for example, about 650 μm to about 900 μm, for example, about 700 μm to about 900 μm, but is not limited thereto.

[0275] In one embodiment, in the case where the second polishing variability index satisfies the above range while the Ri and the Gi each satisfy the above range, it can be more favorable in terms of achieving polishing performance by the structural characteristics of the polishing variable layer 101.

[0276] In the case where the first surface 11 includes at least one groove 14 having a depth less than or equal to the overall thickness of the polishing variable layer 101, in the polishing variable layer 101, the depth variation rate (%) of the groove 14 according to the third formula can be about 20% to about 100%.

[0277] Referring to Figure 1 In the polishing process, the depth dl of the groove 14 is changed from the depth (Gi) at the life introduction time point to the depth (Gf) at the life end time point. Specifically, the depth dl of the groove 14 is gradually shallowed according to the process in which the first surface 11 is removed by polishing performed by bringing the first surface 11 and the polished surface of the polishing object into physical contact with each other. At this time, the value of the 3rd equation constituted by the depth (Gi) of the groove at the life introduction time point and the depth (Gf) of the groove at the life end time point can satisfy the above range only on the basis that the elongation, tensile strength, hardness, and the like of the polishing variable layer 101 are maintained at an appropriate level. Specifically, if the physical properties of the polishing variable layer 101 do not satisfy the appropriate level, there is a risk that the influence of the change in the fluidity of the polishing slurry or the like on the polishing performance becomes greater as the depth dl of the groove is gradually shallowed, thereby causing a sharp decline in the overall polishing performance. When the value of the 3rd equation satisfies the above range, the polishing variable layer 101 of the implementation example can exhibit optimal physical properties corresponding thereto, and on the basis thereof, even in the case where the depth dl of the groove is shallowed, it is possible to achieve excellent polishing performance throughout the polishing process by the semiconductor device manufacturing method by minimizing the influence on the polishing performance.

[0278] When the polishing pad 110 includes at least one groove on the first surface 11, the width wl of the groove 14 can be about 0.2 mm to about 1.0 mm, for example, about 0.3 mm to about 0.8 mm, for example, about 0.4 mm to about 0.7 mm. When the width of the groove 14 satisfies the above range, it is possible to appropriately secure the size of the contact area of the polished surface of the polishing object 130 and the first surface 11, and to achieve excellent final polishing performance by securing the fluidity of the polishing liquid or the polishing slurry applied to the first surface 11 at an appropriate level.

[0279] When the polishing pad 110 includes a plurality of grooves 14 on the first surface 11, it is possible to appropriately design the pitch pl of the groove 14 defined by the interval between the two adjacent grooves 14 in the same context as the width wl of the groove 14, thereby helping to achieve the required polishing performance in the semiconductor device manufacturing method. For example, the pitch pl of the groove 14 can be about 1.5 mm to about 5.0 mm, for example, about 1.5 mm to about 4.0 mm, for example, about 1.5 mm to about 3.0 mm.

[0280] Referring to Figure 4In an embodiment, the method of manufacturing a semiconductor device can further include a step of supplying a polishing slurry 150 to the first surface 11 of the polishing pad 110. For example, the polishing slurry 150 can be supplied to the first surface 11 by a supply nozzle 140.

[0281] The flow rate of the polishing slurry 150 sprayed through the supply nozzle 140 can be about 10 ml / min to about 1000 ml / min, for example, about 10 ml / min to about 800 ml / min, for example, about 50 ml / min to about 500 ml / min, but is not limited thereto.

[0282] The polishing slurry 150 can include a silica slurry or a ceria slurry, but is not limited thereto.

[0283] Referring to Figure 4 The polishing object 130 can be polished while being pressurized against the first surface 11 at a prescribed load in a state of being mounted to a polishing head 160. The polishing object 130 can be mounted with its polished surface facing the first surface 11 when mounted to the polishing head 160. The load with which the polished surface of the polishing object 130 is pressurized against the first surface 11 can be appropriately designed according to the kind and purpose of the polished surface, but for example, can be about 0.01 psi to about 20 psi, for example, about 0.1 psi to about 15 psi.

[0284] In an embodiment, in order to maintain the first surface 11 of the polishing pad 110 in a state suitable for polishing, the method of manufacturing a semiconductor device can further include a step of processing the first surface 11 by a dresser 170 while polishing the polishing object 130.

[0285] The dresser 170 can function to pressurize the first surface 11 while rotating at a prescribed rotational speed, thereby roughening the first surface 11. The rotational speed of the dresser 170 can be, for example, about 50 rpm to about 150 rpm, for example, about 80 rpm to about 120 rpm. Through surface processing by rotation of the dresser 170, the first surface 11 can be maintained in an optimal surface state throughout the polishing process, thereby achieving the effect of extending the polishing life.

[0286] The pressing pressure of the dresser 170 against the first surface 11 can be, for example, about 1 lbf to about 12 lbf, and can be, for example, about 3 lbf to about 9 lbf. By pressing the dresser 170 under such conditions to perform surface treatment, the first surface 11 can maintain an optimal surface state throughout the polishing process, thereby achieving the effect of extending the polishing life.

[0287] Specific embodiments of the present application are described below. However, the embodiments described below are only for specifically exemplifying or explaining the present application, and are not intended to limit the present application, and the scope of the present application is determined by the scope of the claims.

[0288] <Examples and Comparative Examples>

[0289] Example 1

[0290] With respect to 100 parts by weight of 2,4-toluene diisocyanate (2,4-TDI), 25 parts by weight of 2,6-toluene diisocyanate (2,6-TDI) and 14 parts by weight of 4,4'-dicyclohexylmethane diisocyanate (H 12(Mw) of 106 g / mol of diethylene glycol (DEG), to prepare a second alcohol component. The mixed raw materials containing the isocyanate component and the polyol component were put into a four-necked flask, and a second composition containing a second urethane-based prepolymer was prepared by conducting a reaction at 80°C. The isocyanate group content (NCO%) in the second composition was made to be 9% by weight. 4,4'-methylenebis(2-chloroaniline) (MOCA) having an amino reactive group was mixed in the second composition as a second curing agent, in such a manner that the molar ratio of the NCO group in the second composition to the NH2 group of the MOCA became 1 : 0.96. In addition, 1.0 parts by weight of a solid foaming agent (Icycell®) as an intumescent particle and 1.0 parts by weight of a silicon-based surfactant (OFX-193) as a second foaming agent were mixed with respect to 100 parts by weight of the second composition as a whole. The second composition was injected into a mold having a width of 1000 mm, a length of 1000 mm, a height of 3 mm, and preheated to 90°C at an ejection rate of 10 kg / min, while nitrogen (N2) as a gaseous foaming agent was injected at an injection rate of 1.0 L / min for the same time as the injection time of the second composition. Next, the second composition was subjected to a post-curing reaction under temperature conditions of 110°C to prepare a sheet. The sheet was subjected to turning processing, and then a polished variable layer having a thickness of 1.0 mm was prepared by processing concentric circular grooves having a width wl of 0.5 mm, a pitch pl of 3.0 mm, and a depth dl of 0.85 mm on the surface.

[0291] A by-product generated in the groove and thickness processing of the polishing variable layer was pulverized into an average particle diameter of 1 to 2 mm (average particle diameter of about 1.5 mm) using a pulverizer. 300 g of the pulverized product and diethylene glycol (DEG) were mixed at a weight ratio of 1:2, and a recovered polyol having a hydroxyl value (OH-v) of 600 (±20) mgKOH / g was obtained by processing treatment at a temperature of 170°C for 6 hours. A first alcohol component including the recovered polyol as a first polyol was prepared, and a first isocyanate component including toluene diisocyanate (TDI) and having an isocyanate group content (NCO%) of 48% by weight was prepared. A first urethane-based prepolymer was prepared by allowing the first alcohol component and the first isocyanate component to react, and in this process, the contents of the respective components were adjusted in such a manner that the isocyanate group content (NCO%) of a first composition including the first urethane-based prepolymer became 12% by weight. An alcohol curing agent (MCNS Corporation, LA-750) including a hydroxyl group as a reaction group and having a hydroxyl value (OH-v) of 750 mgKOH / g was mixed in the first composition as a first curing agent in such a manner that the molar ratio of the NCO group in the first composition to the OH group of the curing agent became 1:1. In addition, 1.0 parts by weight of a silicon-based surfactant (OFX-193) was mixed with respect to 100 parts by weight of the first composition as a whole. The first composition was injected into a mold having a width of 1000 mm, a length of 1000 mm, a height of 100 mm, and preheated to 90°C at a discharge rate of 10 kg / min, and nitrogen (N2) was injected as a gaseous blowing agent at an injection rate of 1.0 L / min for the same time as the injection time of the first composition. Next, the first composition was subjected to a post-curing reaction at a temperature of 110°C for 10 hours to prepare a cured product. The cured product of the first composition was subjected to cutting processing at a thickness of 1 mm to prepare a plurality of polishing invariable layers.

[0292] On the other hand, a buffer layer having a urethane-based resin impregnated in a polyester resin nonwoven fabric structure and having a thickness of 1.1 mm was prepared.

[0293] Double-sided tapes were attached to the opposite surface of the surface of the polishing variable layer on which the grooves were formed, both surfaces of the polishing invariable layer, and one surface of the buffer layer, respectively, and then the polishing variable layer, the polishing invariable layer, and the buffer layer were sequentially stacked in such a manner that the double-sided tape attachment surfaces were brought into contact with each other to prepare a polishing pad having a total thickness of 3.2 (±0.5) mm.

[0294] Comparative Example 1

[0295] A polishing variable layer and a buffer layer were included without the polishing invariable layer of Example 1, and in the production of the polishing variable layer, in addition to injecting the second composition into a mold of 1000 mm in width, 1000 mm in length, 3 mm in height, and preheated to 90°C, the final thickness of the cured product of the first composition was turned to 2.0 mm to produce a polishing variable layer. In addition, in addition to attaching double-sided tape to the surface of the polishing variable layer on which grooves were formed and one surface of the buffer layer, respectively, and then disposing the double-sided tape-attached surfaces so as to be in contact with each other, and then producing a polishing pad having a total thickness of 3.2 (±0.5) mm by laminating them, a polishing pad was produced in the same manner.

[0296] [Table 1]

[0297]

[0298]

[0299] <Measurement and Evaluation>

[0300] Experimental Example 1: Polishing Pad Hardness Evaluation

[0301] The Shore D hardness of the first surface as the polishing surface was measured for each of the polishing pads of the Examples and the Comparative Examples. Specifically, samples were prepared by cutting the width and length to 5 cm x 3 cm in size, and then each sample was stored at a temperature of 25°C for 12 hours, and then measured using a Shore D hardness tester. The results are shown in Table 2 below.

[0302] Experimental Example 2: Polishing Pad Compression Rate Evaluation

[0303] The initial thickness D1 under no load was measured for each of the polishing pads of the Examples and the Comparative Examples, and then the thickness after deformation under pressure (D2) was measured under the pressure condition of pressing for 1 minute at room temperature using a cylindrical weight of 2400 g and 25 mm in diameter, and then the compression rate (%) was derived using the formula (D1-D2) / D1 x 100.

[0304] Experimental Example 3: Polishing Variable Layer Evaluation

[0305] For each of the Examples and the Comparative Examples, the surface roughness (Ri) of the first surface of the polishing variable layer before being applied to the polishing process was measured based on the center line average roughness (Ra) after the production of each polishing pad was completed, and then the overall thickness (Ti) of each polishing pad and the depth (Gi) of the grooves on each first surface were measured.

[0306] Next, for each polishing pad, silicon oxide (SiO2) was deposited on a silicon wafer having a diameter of 300 mm by a chemical vapor deposition (CVD) process. The polishing pad was installed on a CMP machine, and the silicon wafer was disposed so that the surface of the silicon oxide layer of the silicon wafer faced the polishing surface of the polishing pad. A calcined cerium dioxide slurry (KC Tech, ACS350) was supplied to the polishing pad at a rate of 250 ml / min, while the silicon wafer was pressed against the polishing surface at a load of 3.0 psi, and the polishing of the silicon dioxide film was performed by setting the rotation speeds of the polishing pad and the silicon wafer at 100 rpm, respectively. After polishing was performed to the point at which the polishing rate changed by 20% compared to the initial polishing rate, the silicon wafer was removed from the carrier and installed on a spin dryer, and then washed with distilled water and dried with nitrogen for 15 seconds.

[0307] For each polishing pad, the point at which the polishing rate changed by 20% compared to the initial polishing rate was taken as the end point of the life of the polishing pad, the surface roughness (Rf) of the first surface of the polishing changeable layer of each dried polishing pad was measured based on the center line average roughness (Ra), and then the overall thickness (Tf) of each polishing pad and the depth (Gf) of the grooves on each first surface were measured.

[0308] Next, the first polishing changeability index and the second polishing changeability index were derived using the first equation and the second equation, and the results are shown in Table 2 below.

[0309] Experimental Example 4: Evaluation of Polishing Performance

[0310] For each of the polishing pads of the examples and the comparative examples, polishing was performed in the same manner as in Experimental Example 3, and then the polishing performance of each was evaluated as described below. The results are shown in Table 2 below.

[0311] (1) Average Polishing Rate

[0312] Polishing was performed in the same manner as in Experimental Example 3, and the change in film thickness of the dried silicon wafer before and after polishing was measured using an optical interference thickness meter (SI-F80R, Kyence) after polishing was performed for 1 minute. Then, the polishing rate was calculated using the following equation. The polishing rate was measured a total of 5 times in this manner, and the average value was taken as the average polishing rate.

[0313]

[0314] (2) Defects

[0315] Polishing was performed in the same manner as in Experimental Example 3, and the number of defects such as scratches was obtained by visually observing the polished surface of the polishing object after polishing for 1 minute. Specifically, after the polishing was completed, the silicon wafer was moved to a cleaner, and washing was performed for 10 seconds using 1% hydrogen fluoride (HF) and pure water (DIW), 1% nitric acid (H2NO3) and pure water (DIW), respectively. Then, the silicon wafer was moved to a spin dryer, washed using pure water (DIW), and dried for 15 seconds using nitrogen (N2). A defect detection device (Tenkor, XP+) was used to visually observe the change in defects of the dried silicon wafer before and after polishing.

[0316] (3) Polishing flatness

[0317] Polishing was performed in the same manner as in Experimental Example 3, and the in-plane film thickness of 49 wafers was measured after polishing for 1 minute, and the polishing flatness (WIWNU: Within Wafer Non Uniformity, %) was derived using the formula (standard deviation of thickness after polishing / average polishing thickness ) x 100.

[0318] [Table 2]

[0319]

[0320] Referring to Table 2, the polishing pad of Example 1 includes a polishing layer having a stacked structure of a polishing variable layer and a polishing invariable layer, and uses a recycled layer to which recycled polyol is applied as the polishing invariable layer, wherein the recycled polyol is prepared by crushing byproducts generated in the groove and thickness processing of the polishing variable layer into crushed particles having an average particle diameter of 1 to 2 mm (average particle diameter of about 1.5 mm) using a crusher, and then preparing recycled polyol by processing the crushed particles. It can be confirmed that the Comparative Example 1 is a polishing pad to which such a recycled layer is not applied, and although the polishing pad of Example 1 includes a recycled structure, it also achieves polishing performance at a level equivalent to that of Comparative Example 1, and has an improved effect in process productivity and economy in addition to the polishing function itself.

Claims

1. A polishing pad, wherein, Including the polished layer; The polishing layer includes: A polished variable layer, featuring a polished surface, and A non-polishing layer is disposed on the opposite side of the polishing surface of the variable polishing layer; The polishing-resistant layer comprises a cured product of a first composition containing a first urethane-based prepolymer. The polished variable layer comprises a cured product of a second composition containing a second urethane-based prepolymer. The first urethane-based prepolymer is a reaction product of a first alcohol component and a first isocyanate component, wherein the first alcohol component comprises a first polyol with a hydroxyl value of 200 mg KOH / g to 900 mg KOH / g. The second urethane-based prepolymer is a reaction product of the second alcohol component and the second isocyanate component. The second alcohol component contains a second polyol with a hydroxyl value of ≥50 mgKOH / g and ≥200 mgKOH / g. The isocyanate group content in the first composition is higher than that in the second composition.

2. The polishing pad according to claim 1, wherein, The interface between the variable polishing layer and the constant polishing layer is a separable interface.

3. The polishing pad according to claim 1, wherein, The variable polishing layer and the constant polishing layer each comprise at least one layer.

4. The polishing pad according to claim 1, wherein, The isocyanate group content in the first composition is from 8% to 20% by weight.

5. The polishing pad according to claim 1, wherein, The first composition further comprises a first curing agent. The first curing agent comprises a compound containing a reactive group selected from the group consisting of amino, hydroxyl, and combinations thereof.

6. The polishing pad according to claim 5, wherein, The first curing agent comprises a compound containing a hydroxyl group as the reactive group. The hydroxyl value of the compound containing the hydroxyl group is greater than 600 mg KOH / g and less than 900 mg KOH / g.

7. The polishing pad according to claim 1, wherein, The second composition further comprises a second curing agent. The second curing agent comprises a compound containing a reactive group selected from the group consisting of amino, hydroxyl, and combinations thereof.

8. The polishing pad according to claim 7, wherein, The second curing agent comprises a compound containing an amino group as the reactive group. The molar ratio of isocyanate groups in the second composition to amino groups in the second curing agent is 1:0.80 to 1:1.

20.

9. The polishing pad according to claim 1, wherein, The isocyanate group content in the second composition is from 5% to 11% by weight.

10. A method of manufacturing a semiconductor device, wherein, Includes the following steps: A polishing pad is provided on a flat plate, the polishing pad comprising a polishing layer having a polishing surface, and The surface to be polished of the object is set to contact the polishing surface, and then the object is polished under pressure while the polishing pad and the object being polished are rotated relative to each other. The polishing layer includes: A polished variable layer, including the polished surface, and A non-polishing layer is disposed on the opposite side of the polishing surface of the variable polishing layer; The polishing invariable layer includes a cured product of a first composition containing a first urethane-based prepolymer, The polishing variable layer includes a cured product of a second composition containing a second urethane-based prepolymer, The first urethane-based prepolymer is a reaction product of a first alcohol component and a first isocyanate component, the first alcohol component containing a first polyol having a hydroxyl value of 200 mgKOH / g to 900 mgKOH / g, The second urethane-based prepolymer is a reaction product of a second alcohol component and a second isocyanate component, the second alcohol component containing a second polyol having a hydroxyl value of 50 mgKOH / g or more and less than 200 mgKOH / g, The isocyanate group content in the first composition is higher than the isocyanate group content in the second composition.

11. The method for manufacturing a semiconductor device according to claim 10, wherein The polishing object is pressed to the polishing surface of the polishing layer at a load of 0.01 psi to 20 psi.

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