Polishing pad and method of fabricating semiconductor devices using the same

Abstract

The present invention provides a polishing pad, by a design of a subdivided structure characteristic in a thickness direction, can provide a physical characteristic suitable for various polishing purposes to various polishing objects, and, unlike the existing polishing pad, in at least a part of the structure, a regenerative or recyclable material is applied, so that environmental friendliness can be achieved. Specifically, the polishing pad includes a polishing layer including a polishing variable layer having a polishing surface, and a polishing invariable layer disposed on the back surface of the polishing surface of the polishing variable layer, the polishing invariable layer can include a cured product of a composition including thermosetting polyurethane particles and a binder.

Description

Technical Field

[0001] This invention relates to a pad for a polishing process, and to a technique for using such a pad in a method for fabricating semiconductor devices. Background Technology

[0002] Chemical mechanical planarization (CMP) or chemical mechanical polishing (CMP) processes can be used for various purposes in a variety of technical fields. CMP processes are performed on a specified polishing surface of the object being polished and can be used to planarize the polished surface, remove aggregated substances, resolve lattice damage, and remove scratches and contaminants, among other things.

[0003] CMP (Chemical Motion Processing) technology in semiconductor manufacturing can be classified according to the material being polished or the shape of the surface after polishing. For example, it can be classified by the material being polished as single-crystal silicon or polysilicon, or by the type of impurities as various oxide films or metal films (such as tungsten (W), copper (Cu), aluminum (Al), ruthenium (Ru), tantalum (Ta), etc.). Furthermore, it can be classified by the shape of the polished surface as processes for improving substrate surface roughness, processes for planarizing height differences caused by multilayer circuit wiring, and device separation processes for selectively forming circuit wiring after polishing.

[0004] CMP (Chemical Motion Processing) can be applied multiple times during the fabrication of semiconductor devices. Semiconductor devices consist of multiple layers, each containing complex and intricate circuit patterns. Furthermore, recent semiconductor devices have trended towards smaller individual chip sizes, with increasingly complex and intricate layer patterns. Therefore, in the fabrication of semiconductor devices, the purpose of CMP extends beyond simply planarizing circuit traces to include trace separation and surface finish, demanding ever more precise and reliable CMP performance.

[0005] This type of polishing pad used in CMP processes is a process component that uses friction to process the polished surface to the desired level. It can be considered one of the most important factors in terms of the thickness uniformity of the polished object, the flatness of the polished surface, and the polishing quality after polishing. Summary of the Invention

[0006] Technical problems to be solved

[0007] In one embodiment of the present invention, a polishing pad is provided, which, through a subdivided structural design in the thickness direction, can provide physical properties suitable for various polishing purposes to various polishing objects. Based on appropriate variability, the polishing performance can be maintained for a long time without degradation during structural changes in the polishing process. Furthermore, unlike existing polishing pads, this pad utilizes recycled or recyclable materials in at least a portion of its structure, thereby achieving environmental friendliness.

[0008] In another embodiment of the present invention, a method for fabricating a semiconductor device is provided. As a method for fabricating a semiconductor device using the polishing pad, the diversity of polished surfaces of the semiconductor substrate can be ensured. While ensuring an appropriate polishing rate for each polished surface, excellent polishing flatness and a minimum level of defect occurrence can be ensured, thereby achieving improved process productivity and economy.

[0009] means for solving problems

[0010] In one embodiment, a polishing pad is provided, comprising a polishing layer including: a polishing variable layer having a polishing surface, and a polishing constant layer disposed on the back side of the polishing surface of the polishing variable layer, wherein the ratio of the Shore D hardness of the polishing variable layer and the polishing constant layer is 0.50 to 1.50.

[0011] The variable polishing layer can account for 30% to 60% of the total volume of the polishing layer.

[0012] According to Equation 1 below, the first polishing variability index of the polishing variable layer can be from 0.1 to 11.0.

[0013] Formula 1

[0014]

[0015] In Equation 1, Ri is the surface roughness Ra of the polished surface at the lifetime initiation time of the polished variable layer, Rf is the surface roughness Ra of the polished surface at the lifetime end time of the polished variable layer, Ti is the total thickness of the polishing pad at the lifetime initiation time of the polished variable layer, and Tf is the total thickness of the polishing pad at the lifetime end time of the polished variable layer.

[0016] The polishing variable layer may include at least one groove on the polished surface, having a depth less than or equal to the total thickness of the polishing variable layer. According to Equation 2, the second polishing variability index of the polishing variable layer may be between 0.1 and 3.5.

[0017] Formula 2

[0018]

[0019] In Equation 2, Ri is the surface roughness Ra of the polished surface at the lifetime initiation time of the polished variable layer, Rf is the surface roughness Ra of the polished surface at the lifetime end time of the polished variable layer, Gi is the depth of the trench at the lifetime initiation time of the polished variable layer, and Gf is the depth of the trench at the lifetime end time of the polished variable layer.

[0020] The polishing variable layer may include at least one groove on the polished surface, having a depth less than or equal to the total thickness of the polishing variable layer, wherein the depth variation rate (%) of the groove may be 20% to 100% according to the following formula 3.

[0021] Formula 3

[0022]

[0023] In Equation 3, Gi is the trench depth at the lifetime initiation time of the polishing variable layer, and Gf is the trench depth at the lifetime end time of the polishing variable layer.

[0024] The Shore D hardness of the total laminate of the polishing pad can be 45 to 70.

[0025] The ratio of the Shore D hardness of the polishing pad stack to the Shore D hardness of the polishing layer can be from 0.95 to 1.10.

[0026] The polishable variable layer may include a thermosetting resin, and the polishable invariant layer may include a thermoplastic resin.

[0027] The polished variable layer may include a cured composition comprising thermosetting polyurethane particles and an adhesive.

[0028] The polishing invariant layer may comprise one selected from the group consisting of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), thermoplastic polyurethane (TPU), and combinations thereof.

[0029] The polish-resistant layer may include a cured composition comprising thermosetting polyurethane particles and an adhesive.

[0030] The interface between the variable polishing layer and the constant polishing layer can be a separable interface.

[0031] The variable polishing layer and the constant polishing layer may each include at least one layer.

[0032] The average particle size of the thermosetting polyurethane particles can be from 20 μm to 3.0 mm.

[0033] The adhesive may comprise a first urethane-based prepolymer and a first curing agent.

[0034] The composition may contain 15 to 150 parts by weight of the adhesive, relative to 100 parts by weight of the thermosetting polyurethane particles.

[0035] The polished variable layer may include a cured composition comprising a second urethane-based prepolymer.

[0036] In another embodiment, a method for fabricating a semiconductor device is provided, comprising: providing a polishing pad including a polishing layer to a surface plate, wherein the polishing layer has a polishing surface; and configuring a polished surface of a polishing object to contact the polishing surface, and then rotating the polishing pad and the polishing object relative to each other under pressure to polish the polishing object; the polishing layer comprising: a polishing variable layer including the polishing surface, and a polishing invariant layer disposed on the back side of the polishing surface of the polishing variable layer; the polishing invariant layer comprising a cured composition comprising thermosetting polyurethane particles and an adhesive.

[0037] The pressure applied to the polished surface of the polished object by the polishing layer can be from 0.01 psi to 20 psi.

[0038] Invention Effects

[0039] The polishing pad, through its subdivided structural design along the thickness direction, can provide physical properties suitable for various polishing purposes to different polishing objects. With appropriate variability in the structural changes during the polishing process, it can maintain polishing performance over a long period. Furthermore, unlike existing polishing pads, this polishing pad can utilize recycled or recyclable materials in at least a portion of its structure, thus ensuring environmental friendliness.

[0040] The method for fabricating the semiconductor device by using the polishing pad can ensure the diversity of polished surfaces of the semiconductor substrate. While ensuring an appropriate polishing rate for each polished surface, it can also ensure excellent polishing flatness and a minimum level of defects, thereby achieving improved process productivity and economic results. Attached Figure Description

[0041] Figure 1 A cross-section of the polished layer in one implementation example is schematically shown.

[0042] Figure 2 The variation of the polished surface of the polished layer in the polishing process is illustrated schematically in one implementation example.

[0043] Figure 3 A cross-section of the polishing pad in one implementation example is schematically shown.

[0044] Figure 4 This is a schematic diagram illustrating a method for fabricating the semiconductor device according to one implementation example. Detailed Implementation

[0045] The embodiments of the present invention will now be described in detail to enable those skilled in the art to readily implement the invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0046] The advantages, features, and implementation methods of the present invention will become clearer from the following implementation examples or embodiments. However, the present invention is not limited to the following implementation examples or embodiments, but can be implemented in various different forms. These implementation examples or embodiments are provided to make the present invention more complete and to fully provide those skilled in the art with the scope of the present invention, which will be defined by the appended claims.

[0047] To clearly illustrate layers and regions, the thickness of a portion of the structure is enlarged and shown in the accompanying drawings as needed. Furthermore, for ease of explanation, the thickness of some layers and regions is exaggerated in the accompanying drawings. Throughout the specification, the same reference numerals denote the same constituent elements.

[0048] In this specification, when a part of a layer, film, region, plate, etc., is referred to as being "above" or "upper" another part, this is interpreted as including not only the case where it is directly "above" another part, but also the case where there are other parts in between. When a part is referred to as being directly "above" another part, it is interpreted as meaning that there are no other parts in between. Similarly, when a part of a layer, film, region, plate, etc., is referred to as being "below" or "lower" of another part, this is interpreted as including not only the case where it is directly "below" another part, but also the case where there are other parts in between. When a part is referred to as being directly "below" another part, it is interpreted as meaning that there are no other parts in between.

[0049] In this specification, the meaning of "~ and above" in indicating a numerical range is interpreted as including the corresponding quantity or more. For example, "two or more" means two or more. Additionally, the description of "X to Y" in a numerical range is interpreted as including the range of either X or Y. For example, "25 to 50" means a numerical range including both 25 and 50.

[0050] The following provides a detailed description of an exemplary implementation of the present invention.

[0051] In one embodiment of the present invention, a polishing pad including a polishing layer is provided. The polishing layer may include: a variable polishing layer having a polishing surface; and a constant polishing layer disposed on the back side of the polishing surface of the variable polishing layer, wherein the ratio of the Shore D hardness of the variable polishing layer to the Shore D hardness of the constant polishing layer may be from 0.50 to 1.50.

[0052] Figure 1 A cross-section along the thickness direction of the polished layer 10 in one implementation example is schematically shown. Hereinafter, "polished surface" and "first surface" can be used as terms referring to the same structure.

[0053] Reference Figure 1 The polishing layer 10 may include the variable polishing layer 101 having the polishing surface 11. Additionally, the polishing layer 10 may include a constant polishing layer 102 provided to support the variable polishing layer 101. The constant polishing layer 102 is detachably bonded to the variable polishing layer 101. Each of the variable polishing layer 101 and the constant polishing layer 102 may include at least one layer.

[0054] In another aspect, the polished layer 10 includes a first surface 11 as a polished surface and a second surface 12 as its back surface. Furthermore, the polished layer 10 includes at least one separable interface 13 between the first surface 11 and the second surface 12. In this specification, a "separable interface" refers to an interface that distinguishes two adjacent layers as discontinuous rather than substantially continuous structures. As an example, the separable interface is an interface that can be disassembled or separated by a specified external force; an adhesion surface where an adhesive layer serves as a medium can correspond to this.

[0055] In the polished layer 10, the ratio of the Shore D hardness of the variable polishing layer 101 and the constant polishing layer 102 can be from about 0.50 to about 1.50. Alternatively, in the polished layer 10, the ratio of the Shore D hardness of two adjacent layers with reference to the separable interface 13 can be from about 0.50 to about 1.50. Figure 1 This example illustrates a case where the separable interface 13 between the first surface 11 and the second surface 12 is a single entity. Referring to this, the ratio of the Shore D hardness of two adjacent layers 101, 102 with reference to the separable interface 13 can be from approximately 0.50 to approximately 1.50. The Shore D hardness ratio can be, for example, from approximately 0.50 to approximately 1.50, from approximately 0.60 to approximately 1.50, from approximately 0.70 to approximately 1.40, or from approximately 0.80 to approximately 1.20. The desired technical effect can be achieved not only when both satisfy the stated range, but also when only one of them satisfies the stated range.

[0056] In one implementation, the ratio H2 / H1 of the Shore D hardness H2 of the polished constant layer to the Shore D hardness H1 of the polished variable layer can be from about 0.5 to about 1.0, for example, from about 0.7 to about 1.0, for example, from about 0.8 to 1.0.

[0057] In one implementation, the ratio H1 / H2 of the Shore D hardness H1 of the polished variable layer to the Shore D hardness H2 of the polished constant layer can be from about 1.0 to about 1.5, for example, from about 1.0 to about 1.4, for example, from about 1.0 to 1.2.

[0058] The polishing pad can be used in polishing processes for various purposes. For example, it can be applied to the fabrication of semiconductor devices. Recently, the required integration density of semiconductor devices has been increasing, and their structures have become more complex in three dimensions. To meet these requirements, precise process control is essential in the fabrication of semiconductor devices. Semiconductor devices comprise thin films of various materials and shapes, and polishing processes requiring precise adjustments to process conditions are needed depending on the material and shape of each thin film. The polishing pad, as one of the elements of this precise process control, can produce drastically different polishing results for the semiconductor device depending on even slight differences in its structure, material, and shape.

[0059] In the polishing pad including the polishing layer 10, the physical properties calculated from its overall structure and / or compositional characteristics are transmitted to the polished surface of the object being polished through the polishing surface 11. At this time, in the polishing layer 10, when the ratio of the Shore D hardness of two adjacent layers 101, 102 based on the separable interface 13 meets the aforementioned range, the polishing characteristics transmitted to the polished surface of the object being polished through the polishing surface 11 can ensure optimal conditions for achieving the target polishing performance of the semiconductor device.

[0060] Reference Figure 1 The polishing layer 10 may include: at least one variable polishing layer 101, which is the region from the polishing surface 11 to the separable interface 13; and at least one constant polishing layer 102, which is the region from the separable interface 13 to the second surface 12. In this specification, "variable polishing layer" refers to a region where the physical properties such as structure and shape and / or chemical properties such as composition change during the polishing process using the polishing pad. "Constant polishing layer" refers to a region where the physical and / or chemical properties remain substantially unchanged during the polishing process using the polishing pad. "Substantively unchanged" should be understood to include not only cases where the physical and / or chemical properties remain completely unchanged, but also cases where polishing is performed under pressure or humidity, and therefore the physical and / or chemical properties may change, but the changes are quite minor compared to the variable polishing layer and can be considered substantially unchanged.

[0061] Figure 1 The example shown is a case where there is one separable interface 13, but depending on the requirements, the polishing layer 10 may also include at least two separable interfaces 13 between the polishing surface 11 and the second surface 12. In this case, the variable polishing layer 101 or the constant polishing layer 102 may each include multiple layers.

[0062] Since the polishing layer 10 is designed to include at least one of the polishing variable layers 101 and at least one of the polishing constant layers 102, a precise structural design can be made in the thickness direction. As an organic interaction of the physical properties of each layer thus stacked in the thickness direction, the polishing performance calculated through the polishing surface 11 can be finely and precisely controlled according to the purpose.

[0063] In one implementation, the variable polishing layer 101 may occupy approximately 30% to approximately 60% of the total volume of the polishing layer 10, for example, approximately 40% to approximately 60% of the total volume, or approximately 45% to approximately 55% of the total volume. Since the volume of the variable polishing layer 101 within the total volume of the polishing layer 10 meets the aforementioned range, it ensures that the aforementioned technical advantages of the variable polishing layer 101 and the constant polishing layer 102 are achieved, while simultaneously facilitating the attainment of a process life of the polishing pad at the target level.

[0064] In one implementation, the first polishing variability index of the polishing variable layer can be from about 0.1 to about 11.0 according to Equation 1 below.

[0065] Formula 1

[0066]

[0067] In Equation 1, Ri is the surface roughness Ra of the first surface at the lifetime introduction time of the polishing variable layer, Rf is the surface roughness Ra of the first surface at the lifetime end time of the polishing variable layer, Ti is the total thickness of the polishing pad at the lifetime introduction time of the polishing variable layer, and Tf is the total thickness of the polishing pad at the lifetime end time of the polishing variable layer.

[0068] As described above, the variable polishing layer 101 is a region where the physical and / or chemical properties change during the polishing process using the polishing pad, and has a predetermined lifespan in providing the desired level of polishing performance. The lifespan initiation point of the variable polishing layer 101 refers to any point in time from the preparation of the variable polishing layer or the polishing pad before its application in the process. Furthermore, the lifespan end point of the variable polishing layer 101 refers to the point in time when the variable polishing layer 101 can no longer achieve the desired polishing performance, thus requiring replacement of the variable polishing layer or the entire polishing pad. For example, the lifespan end point can be defined as the point in time when the polishing rate of the polished surface of the object being polished changes by 20% compared to the initial polishing rate within one hour after the start of polishing. In other words, the initial polishing rate is the polishing rate value measured within one hour after the start of polishing of the polished surface, and the lifespan end point can be defined as the point in time representing a 20% increase or a 20% decrease in the polishing rate of the polished surface compared to the initial polishing rate.

[0069] The first polishing variability index takes the surface roughness Ri and Rf at the beginning and end of the lifetime of the polishing variable layer 101, and the total thickness Ti and Tf of the polishing pad 110 as constituent elements. The first polishing variability index according to Equation 1 can be used as an indicator of the variable performance of the polishing variable layer 101. That is, when the value of Equation 1 for the polishing variable layer represents the aforementioned range, i.e., from about 0.1 to about 11.0, the polishing variable layer, by maintaining the corresponding variability, can continuously and uniformly exhibit structural features optimal for polishing efficiency throughout its entire lifetime when used as part of the structure of the polishing layer 10.

[0070] In one implementation, the first polishing variability index may be from about 0.1 to 11.0, for example, from about 0.1 to about 9.0, for example, from about 0.2 to about 9.0, for example, from about 0.2 to about 8.5, for example, from about 0.2 to about 8.0, for example, from about 0.2 to about 7.5, for example, from about 0.5 to about 7.5, for example, from about 0.8 to about 7.5, for example, from about 0.9 to about 7.5, for example, from about 1.0 to about 6.0, for example, from about 1.8 to 3.5, for example, from about 1.8 to 2.5.

[0071] The Ti can be, for example, 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.

[0072] The Ri may be, for example, 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.

[0073] In one implementation, when Ti and Ri satisfy the above ranges, and the first polishing variability index also satisfies the above ranges, it may be more advantageous to achieve polishing performance based on the structural characteristics of the polishing variable layer 101.

[0074] In one implementation, the variable polishing layer 101 may include at least one groove 14 on the polishing surface 11, having a depth d1 less than or equal to the total thickness D1 of the variable polishing layer 101. The groove 14 serves to appropriately achieve physical polishing characteristics by adjusting the flowability of the polishing fluid or slurry supplied to the polishing surface 11 during a polishing process using the polishing pad, or by adjusting the size of the area in direct contact between the polishing surface 11 and the surface to be polished.

[0075] For example, the polishing pad 110 may include a plurality of grooves 14 on the polishing surface 11. In one implementation, the planar shape of the polishing pad 110 may actually be circular, and the plurality of grooves 14 may be concentric circular structures arranged at predetermined intervals from the center of the planar surface of the polishing pad 110 toward its ends. In another embodiment, the plurality of grooves 14 may be radial structures continuously formed from the center of the planar surface of the polishing pad 110 toward its ends. In yet another embodiment, the plurality of grooves 14 may simultaneously include concentric circular grooves and radial grooves.

[0076] In the polishing variable layer 101, which forms the region from the polished surface 11 to the separable interface 13, when the polished surface 11 includes at least one groove 14, the second polishing variability index of the polishing variable layer 101 can be from about 0.1 to about 3.5 according to the following formula 2.

[0077] Formula 2

[0078]

[0079] In Equation 2, Ri is the surface roughness Ra of the first surface at the lifetime initiation time of the polished variable layer, Rf is the surface roughness Ra of the first surface at the lifetime end time of the polished variable layer, Gi is the depth of the trench at the lifetime initiation time of the polished variable layer, and Gf is the depth of the trench at the lifetime end time of the polished variable layer.

[0080] The descriptions of the lifetime initiation and lifetime end times of the polishing variable layer 101 are the same as those regarding the first polishing variability index according to Equation 1. When the second polishing variability index of the polishing variable layer 101 satisfies the aforementioned range, the polishing variable layer 101 can provide the most suitable structure in terms of the fluidity of the polishing liquid or polishing slurry, ensuring a suitable level of direct contact area on the first surface provided to the polished surface, which may be more conducive to ensuring the polishing rate within the target range.

[0081] In one implementation, the second polishing variability index may be from about 0.1 to about 3.5, for example, from about 0.1 to about 3.3, for example, from about 0.1 to about 3.0, for example, from about 0.1 to about 2.0, for example, from about 0.3 to about 1.8, for example, from about 0.5 to about 1.5, for example, from about 0.5 to about 1.2, for example, from about 0.5 to 1.0, for example, from about 0.6 to about 1.0.

[0082] For example, the Gi 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.

[0083] In one implementation, when Ri and Gi satisfy the above ranges, and the second polishing variability index also satisfies the above ranges, it may be more advantageous to achieve polishing performance based on the structural features of the polishing variable layer 101.

[0084] In one implementation, in the polishing variable layer 101, the first polishing variability index and the second polishing variability index can each simultaneously satisfy the aforementioned ranges. When the first polishing variability index and the second polishing variability index each satisfy the aforementioned ranges, the polishing variable layer 101 can have structural features most suitable for polishing efficiency as part of the structure of the polishing layer 10. In particular, it can provide a structure most suitable for the fluidity of the polishing fluid or polishing slurry, and ensure the direct contact area on the first surface provided to the polished surface at an appropriate level, which may be more conducive to ensuring the polishing rate within the target range. Furthermore, it may be more conducive to achieving constant polishing performance so as to maintain the aforementioned advantages throughout its entire lifespan.

[0085] When the polished surface 11 includes at least one groove 14 having a depth less than or equal to the total thickness of the polished variable layer 101, the depth variation rate (%) of the groove 14 in the polished variable layer 101 according to the following formula 3 can be from about 20% to about 100%.

[0086] Formula 3

[0087]

[0088] In Equation 3, Gi is the trench depth at the lifetime initiation time of the polishing variable layer 101, and Gf is the trench depth at the lifetime end time of the polishing variable layer 101.

[0089] The matters concerning the lifetime initiation and end time of the polishing variable layer 101, as well as the matters concerning Gi and Gf, are the same as those concerning the second polishing variability index as described above.

[0090] In one implementation, the trench depth variation rate according to Equation 3 can be from about 20% to about 80%, for example, from about 30% to 80%, for example, from about 40% to about 80%, for example, from about 45% to about 75%, for example, from about 50% to about 70%.

[0091] In one implementation, the trench depth variation rate according to Equation 3 can be from about 20% to about 80%, for example, from about 30% to 80%, for example, from about 40% to about 80%, for example, from about 40% to about 70%, for example, from about 40% to about 50%.

[0092] Reference Figure 1 The depth d1 of the groove 14 varies during the polishing process from the depth Gi at the beginning of the lifespan to the depth Gf at the end of the lifespan. Specifically, as the polishing surface 11 comes into physical contact with the surface to be polished, the depth d1 of the groove 14 gradually becomes shallower through the grinding process of the polishing surface 11. At this time, the value of Equation 3, which takes the depth Gi of the groove at the beginning of the lifespan and the depth Gf of the groove at the end of the lifespan as elements, can only meet the above range if the physical properties of the polishing variable layer 101, such as elongation, tensile strength, and hardness, are properly supported. Specifically, if the physical properties of the polishing variable layer 101 are not properly supported, the impact of changes in the fluidity of the polishing slurry on the polishing performance increases as the depth d1 of the groove becomes shallower, thus posing a risk of a rapid decline in overall polishing performance. Since the value of Equation 3 satisfies the aforementioned range, the polishing variable layer 101 according to one implementation example can exhibit correspondingly optimal physical properties. Based on this, even if the depth d1 of the groove becomes shallower, excellent polishing performance can be achieved throughout the polishing process by minimizing the impact on polishing performance. Furthermore, by maximizing the use period of the polishing variable layer 101, the lifespan of the polishing pad can be extended.

[0093] Reference Figure 1The width w1 of the groove 14 may affect the size of the physical contact area between the polishing surface 11 and the polished surface of the object being polished during the polishing process. Therefore, by appropriately designing the width w1 of the groove 14 according to the type of object being polished, the type of polishing liquid or polishing slurry, and the target polishing performance, the desired polishing performance can be achieved. For example, the width w1 of the groove 14 can be from about 0.2 mm to about 1.0 mm, for example, from about 0.3 mm to about 0.8 mm, for example, from about 0.4 mm to about 0.7 mm, for example, from about 0.4 mm to about 0.6 mm.

[0094] When the polishing variable layer 101 includes a plurality of grooves 14 on the polishing surface 11, the pitch p1 of the grooves 14, defined as the interval between two adjacent grooves 14, is also appropriately designed with the same technical concept as the width w1 of the grooves 14, thereby helping to achieve the desired polishing performance. For example, the pitch p1 of the grooves 14 can be from about 1.5 mm to about 5.0 mm, for example, from about 1.5 mm to about 4.0 mm, for example, from about 1.5 mm to about 3.0 mm.

[0095] The numerical ranges of the width w1 and spacing p1 of the grooves can be structural configurations that remain essentially unchanged during the polishing process, or, for example, each range can be a value determined based on the lifetime initiation time of the polishing variable layer 101.

[0096] In one implementation, the variable polishing layer 101 and the constant polishing layer 102 can be made of different materials. In this specification, "different materials" should be understood to include not only cases where there is no overlap between components, but also cases where, even if some components are the same, the overall composition is different, and therefore they are identified as heterogeneous materials. By constituting the variable polishing layer 101 and the constant polishing layer 102 with different materials, the physical properties of the polishing pad in the thickness direction can be designed more precisely and finely, thereby enabling polishing performance for various purposes according to various applications.

[0097] In one implementation, the variable polishing layer may comprise a thermosetting resin, and the constant polishing layer may comprise a thermoplastic resin. In this case, the physical properties of the polishing pad in the thickness direction can be designed more precisely and finely, thereby enabling polishing performance for various purposes according to various applications.

[0098] For example, the polished variable layer 101 may comprise a cured pre-composition containing a urethane-based prepolymer. In one embodiment, the cured product may be a thermosetting product. In another embodiment, the pre-composition may further comprise a curing agent and a foaming agent. The term "prepolymer" refers to a polymer with a low molecular weight whose degree of polymerization stops at an intermediate stage to facilitate molding during the cured product preparation process. The prepolymer itself undergoes additional curing processes such as heating and / or pressurization, or is mixed and reacted with another polymerizable compound, such as a heterogeneous monomer or an additional compound of the heterogeneous prepolymer, to form the final cured product.

[0099] In one implementation, the urethane-based prepolymer can be prepared by reacting an isocyanate compound with a polyol compound.

[0100] The isocyanate compound used in the preparation of the urethane-based prepolymer can be selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and combinations thereof. For example, the isocyanate compound may contain aromatic diisocyanates. For example, the isocyanate compound may contain both aromatic and alicyclic diisocyanates.

[0101] The isocyanate compound may include, for example, 2,4-toluenediisocyanate (2,4-TDI), 2,6-toluenediisocyanate (2,6-TDI), naphthalene-1,5-diisocyanate, p-phenylenediisocyanate, tolidinediisocyanate, 4,4'-diphenylmethanediisocyanate, hexamethylenediisocyanate, dicyclohexylmethanediisocyanate, and 4,4'-dicyclohexylmethanediisocyanate. 12 MDI, isophorone diisocyanate, and combinations thereof constitute one of the groups.

[0102] "Polyol" refers to a compound containing at least two hydroxyl groups (-OH) per molecule. In one embodiment, the polyol compound may comprise a diol compound having two hydroxyl groups, i.e., a diol or glycol, or a triol compound having three hydroxyl groups, i.e., a triol compound.

[0103] The polyol compound may include one selected from the group consisting of polyether polyol, polyester polyol, polycarbonate polyol, acrylic polyol, and combinations thereof.

[0104] The polyol compound may comprise one of the following groups: polytetramethylene ether glycol (PTMG), 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 triol, and combinations thereof.

[0105] The weight-average molecular weight (Mw) of the polyol compound can be from about 100 g / mol to about 3000 g / mol, for example, from about 100 g / mol to about 2000 g / mol, for example, from about 100 g / mol to about 1800 g / mol.

[0106] In one embodiment, the polyol compound may comprise a low molecular weight polyol with a weight-average molecular weight (Mw) of about 100 g / mol or more and less than about 300 g / mol, and a high molecular weight polyol with a weight-average molecular weight (Mw) of about 300 g / mol or more and less than about 1800 g / mol. The weight-average molecular weight (Mw) of the high molecular weight polyol may, for example, be about 500 g / mol or more and less than about 1800 g / mol, or, for example, about 700 g / mol or more and less than about 1800 g / mol. In this case, the polyol compound may form a suitable crosslinking structure in the urethane-based prepolymer, which may be more advantageous for the polished variable layer 101 formed by curing the precomposition containing the urethane-based prepolymer under specified process conditions to achieve the aforementioned effects.

[0107] The weight-average molecular weight (Mw) of the urethane-based prepolymer can be from about 500 g / mol to about 3000 g / mol, for example, from about 600 g / mol to about 2000 g / mol, or from about 800 g / mol to about 1000 g / mol. When the urethane-based prepolymer has a degree of polymerization corresponding to the above-mentioned weight-average molecular weight (Mw), it may be more advantageous for the polished variable layer 101 formed by curing the precomposition under specified process conditions to achieve the above-mentioned effects.

[0108] In one embodiment, the isocyanate compound used to prepare the urethane-based prepolymer may comprise an aromatic diisocyanate. For example, the aromatic diisocyanate may comprise 2,4-toluene diisocyanate (2,4-TDI), specifically, it may comprise both 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI). Additionally, for example, the polyol compound used to prepare the urethane-based prepolymer may comprise polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

[0109] In another embodiment, the isocyanate compound used to prepare the urethane-based prepolymer may comprise aromatic diisocyanates and alicyclic diisocyanates. For example, the aromatic diisocyanate may comprise 2,4-toluene diisocyanate (2,4-TDI), specifically 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI). For example, the alicyclic diisocyanate may comprise 4,4'-dicyclohexylmethane diisocyanate (H... 12 MDI). Additionally, for example, the polyol compound used to prepare the urethane-based prepolymer may comprise polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

[0110] In one implementation, the total weight of the polyol compound may be from about 100 parts by weight to about 180 parts by weight relative to 100 parts by weight of the isocyanate compound. For example, it may be about more than 100 parts by weight and less than about 180 parts by weight, for example, it may be from about 110 parts by weight to about 160 parts by weight, for example, it may be from about 120 parts by weight to about 150 parts by weight.

[0111] In another embodiment, relative to 100 parts by weight of the isocyanate compound, the total weight of the polyol compound may be greater than about 180 parts by weight and less than about 250 parts by weight, for example, it may be from about 185 parts by weight to about 250 parts by weight, for example, it may be from about 190 parts by weight to about 240 parts by weight.

[0112] In one embodiment, the polyol compound comprises polytetramethylene ether glycol (PTMG), and the content of PTMG relative to 100 parts by weight of the isocyanate compound can be from about 100 parts by weight to about 250 parts by weight, for example, it can be more than about 100 parts by weight and less than about 250 parts by weight, for example, it can be from about 110 parts by weight to about 220 parts by weight, for example, it can be from about 110 parts by weight to about 140 parts by weight.

[0113] In another embodiment, the polyol compound comprises polytetramethylene ether glycol (PTMG), and the content of PTMG may be from about 150 parts by weight to about 250 parts by weight, for example, from about 180 parts by weight to about 230 parts by weight, relative to 100 parts by weight of the isocyanate compound.

[0114] In one embodiment, the polyol compound comprises diethylene glycol (DEG), and the content of diethylene glycol (DEG) may be from about 1 part by weight to about 20 parts by weight, for example, from about 1 part by weight to about 15 parts by weight, relative to 100 parts by weight of the isocyanate compound.

[0115] In one embodiment, the isocyanate compound comprises the aromatic diisocyanate, which comprises 2,4-TDI and 2,6-TDI, wherein the content of 2,6-TDI may be from about 1 part by weight to about 40 parts by weight relative to 100 parts by weight, for example, from about 1 part by weight to about 30 parts by weight, for example, from about 3 parts by weight to about 28 parts by weight, for example, from about 20 parts by weight to about 30 parts by weight.

[0116] In another embodiment, the content of 2,6-TDI may be from about 1 part by weight to about 40 parts by weight relative to 100 parts by weight of the 2,4-TDI, for example, from about 1 part by weight to about 30 parts by weight, for example, from about 1 part by weight to about 20 parts by weight, for example, from about 1 part by weight to about 10 parts by weight.

[0117] In one embodiment, the isocyanate compound comprises the aromatic diisocyanate and the alicyclic diisocyanate, wherein the content of the alicyclic diisocyanate may be from about 5 parts by weight to about 30 parts by weight relative to the total 100 parts by weight of the aromatic diisocyanate, for example, from about 10 parts by weight to about 25 parts by weight.

[0118] When the pre-composition satisfies the above-described compositional characteristics, the polishing variable layer 101 prepared by curing the pre-composition can exhibit appropriate physical / mechanical properties, and the groove depth variation rate according to Formula 3 satisfies the above-described range, thus contributing to the maximization of uniform polishing performance and lifespan. Furthermore, based on these physical / mechanical properties, the polishing surface 11 provides excellent rigidity and elasticity to the polished object, thereby facilitating the achievement of superior polishing performance.

[0119] The isocyanate group content (NCO%) of the precomposition can be from about 5% by weight to about 11% by weight, for example, from about 5% by weight to about 10% by weight. In one embodiment, the isocyanate group content (NCO%) can be from about 5% by weight to about 8.5% by weight, and in another embodiment, the isocyanate group content (NCO%) can be from about 8.5% by weight to about 10% by weight. The "isocyanate group content" refers to the percentage by weight of isocyanate groups (-NCO) that have not undergone urethane reaction and exist as free reactive groups in the total weight of the precomposition. The isocyanate group content (NCO%) of the precomposition can be designed by comprehensively adjusting the content of the types of monomers used to prepare the urethane-based prepolymer, the process conditions such as temperature and pressure of the urethane-based prepolymer preparation process, and the types of additives used in the preparation of the urethane-based prepolymer. When the isocyanate group content meets the specified range, it is advantageous for the polishing variable layer 101 prepared by curing the pre-composition to ensure appropriate physical / mechanical properties for application in a stacked state with the polishing constant layer 102, which may thus be advantageous for imparting excellent polishing performance to the polished object through the polishing surface 11.

[0120] In one embodiment, the precomposition may further comprise a curing agent. The curing agent is a compound used to chemically react with the urethane-based prepolymer to form a final cured structure in the polished variable layer 101, and may comprise, for example, an amine compound or an alcohol compound. Specifically, the curing agent may comprise one selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, aliphatic alcohols, and combinations thereof.

[0121] For example, the curing agent may comprise a compound selected from 4,4'-methylenebis(2-chloroaniline) (MOCA), diethyltoluenediamine (DETDA), diaminodiphenylmethane, dimethylthio-toluenediamine (DMTDA), and propanediol bis(p-aminobenzoate). One of the following groups: bisp-aminobenzoate, methylenebis-methylanthranilate, diaminodiphenylsulfone, m-xylylenediamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, bis(4-amino-3-chlorophenyl)methane, and combinations thereof.

[0122] The pre-composition, relative to 100 parts by weight of total weight, may contain about 18 parts by weight to about 27 parts by weight, for example, about 19 parts by weight to about 26 parts by weight, for example, about 20 parts by weight to about 26 parts by weight of the curing agent. Achieving the target performance of the polishing pad is more advantageous when the content of the curing agent meets the aforementioned range.

[0123] The molar ratio (NCO:reactive group) of the isocyanate group (-NCO) in the pre-composition to the reactive group in the curing agent can be from about 1:0.80 to about 1:1.20, for example, from about 1:0.90 to about 1:1.10, for example, from about 1:0.90 to about 1:1.00, for example, more than about 1:90 and less than about 1:1.00. The reactive group can vary depending on the type of curing agent, for example, it can be an amino group (-NH2) or a hydroxyl group (-OH). When the molar ratio of the isocyanate group in the pre-composition to the reactive group in the curing agent meets the above range, a suitable crosslinking structure can be formed by the chemical reaction between the urethane prepolymer in the pre-composition and the curing agent. As a result, the polishing variable layer 101 ensures appropriate levels of physical / mechanical properties such as tensile strength and elongation, thereby transferring excellent polishing performance to the polished surface of the object being polished through the polishing surface 11.

[0124] The polishing variable layer 101 may be a porous structure including a plurality of pores 15. The plurality of pores 15 located on the uppermost surface of the polishing variable layer 101 expose at least a portion of their interior to the outside to impart a specified surface roughness to the polished surface 11. Figure 2 The structural changes of the polished surface 11 in one implementation example during the polishing process are schematically shown. Specifically, Figure 2 This is a schematic diagram illustrating the structural changes of a portion of the plurality of pores 15 exposed to the outside on the polished surface 11 during polishing in one implementation example. (Refer to...) Figure 2 Since the plurality of pores 15 are dispersed throughout the polishing variable layer 101, a continuous surface roughness can be achieved even as the uppermost surface is gradually cut through during the polishing process through the polishing surface 11. However, with the pores 15 exposed on the polishing surface 11, the portion corresponding to the boundary between the polishing surface 11 and the pores 15 deforms under physical pressure as the polishing process continues under specified pressure conditions. This phenomenon affects the change in the surface roughness of the polishing surface 11.

[0125] In one implementation, the average size of the plurality of pores 15 included in the polishing variable layer 101 can be from about 5 μm to about 50 μm, for example, from about 5 μm to about 40 μm, for example, from about 10 μm to about 40 μm, for example, from about 10 μm to about 35 μm. Since the plurality of pores satisfy the above-mentioned sizes, the first polishing variability index according to Formula 1 can advantageously satisfy the range, thus making it more advantageous to achieve the target polishing performance itself and to achieve uniform performance throughout the overall lifetime of the polishing variable layer. The average size of the plurality of pores 15 is a two-dimensional value, which is based on the number mean of pore diameters measured on a projection map of the pore size taken using an imaging tool such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM), wherein the pores are those exposed on the outside of a surface based on the lifetime introduction time of the polishing variable layer 101.

[0126] The pre-composition may further comprise a foaming agent. The foaming agent is a component used to form the porous structure in the polished variable layer 101 and may comprise one selected from the group consisting of solid foaming agents, gaseous foaming agents, liquid foaming agents, and combinations thereof. In one implementation, the foaming agent may comprise a solid foaming agent, a gaseous foaming agent, or a combination thereof.

[0127] The solid foaming agent may contain expandable particles. These expandable particles, which are particles that expand under heat or pressure, allow the final pore size to be determined by factors such as applied heat or pressure during the preparation of the polished variable layer 101. The expandable particles may include thermally expanded particles, unexpanded particles, or a combination thereof. "Temperaturely expanded" particles, meaning particles that have pre-expanded by heat, refer to particles whose size changes little or almost nothing due to the heat or pressure applied during the preparation of the polished variable layer. "Unexpanded" particles, meaning particles that have not pre-expanded, refer to particles whose final size is determined by the heat or pressure applied during the preparation of the polished layer.

[0128] The average particle size of the expandable particles can be from about 5 μm to about 200 μm, for example, from about 20 μm to about 50 μm, for example, from about 21 μm to about 50 μm, for example, from about 21 μm to about 40 μm. When the expandable particles are thermally expanded particles, the average particle size can refer to the average particle size of the thermally expanded particles themselves; when the expandable particles are unexpanded particles, the average particle size can refer to the average particle size after expansion due to heat or pressure.

[0129] The expandable particles may comprise: a resin outer skin; and an expansion-inducing component present inside the outer skin.

[0130] For example, the outer skin may comprise a thermoplastic resin, which may be one or more selected from the group consisting of vinyl chloride copolymers, acrylonitrile copolymers, methacrylonitrile copolymers, and acrylic copolymers.

[0131] The swelling-inducing component may include one selected from the group consisting of hydrocarbon compounds, chlorofluorocarbons, trialkylsilane compounds, and combinations thereof.

[0132] Specifically, the hydrocarbon compound may comprise one selected from the group consisting of ethane, ethylene, propane, propylene, n-butane, isobutene, butene, isobutene, n-pentane, isopentane, n-hexane, heptane, petroleum ether, and combinations thereof.

[0133] The fluorochloro compound may include one selected from the group consisting of trichlorofluoromethane (CCl3F), dichlorodifluoromethane (CCl2F2), chlorotrifluoromethane (CClF3), tetrafluoroethylene (CClF2-CClF2), and combinations thereof.

[0134] The trialkylsilane compound may comprise one selected from the group consisting of tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, trimethyl-n-propylsilane, and combinations thereof.

[0135] The solid foaming agent may optionally contain inorganic component-treated particles. For example, the solid foaming agent may contain inorganic component-treated expandable particles. In one embodiment, the solid foaming agent may contain silica (SiO2) particle-treated expandable particles. The inorganic component treatment of the solid foaming agent can prevent the aggregation of multiple particles. The chemical, electrical, and / or physical properties of the surface of the inorganic component-treated solid foaming agent may differ from those of the solid foaming agent without inorganic component treatment.

[0136] Based on 100 parts by weight of the urethane-based prepolymer, the content of the solid foaming agent can be from about 0.5 parts by weight to about 10 parts by weight, for example, from about 1 part by weight to about 3 parts by weight, for example, from about 1.3 parts by weight to about 2.7 parts by weight, for example, from about 1.3 parts by weight to about 2.6 parts by weight.

[0137] The gaseous foaming agent may contain an inert gas. The gaseous foaming agent can be added during the reaction of the urethane-based prepolymer with the curing agent to serve as a pore-forming element.

[0138] There are no particular limitations on the type of inert gas, as long as it is a gas that does not participate in the reaction between the urethane-based prepolymer and the curing agent. For example, it may include one selected from the group consisting of nitrogen (N2), argon (Ar), helium (He), and combinations thereof. Specifically, the inert gas may include nitrogen (N2) or argon (Ar).

[0139] In one embodiment, the foaming agent may comprise a solid foaming agent. For example, the foaming agent may be formed solely from a solid foaming agent.

[0140] The solid foaming agent may contain expandable particles, which may include thermally expandable particles. For example, the solid foaming agent may consist only of thermally expandable particles. While the variability of the pore structure decreases when it is composed only of thermally expandable particles and does not contain the unexpanded particles, predictability increases, thus facilitating the achievement of uniform pore characteristics across all regions of the polished variable layer.

[0141] In one embodiment, the thermally expanded particles can be particles having an average particle size of about 5 μm to about 200 μm. The average particle size of the thermally 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 size is defined as the D50 of the thermally expanded particles.

[0142] In one implementation example, the density of the thermally expanded particles can be approximately 30 kg / m³. 3 Approximately 80 kg / m 3 For example, approximately 35 kg / m 3 Approximately 80 kg / m 3 For example, approximately 35 kg / m 3 Approximately 75 kg / m 3 For example, approximately 38 kg / m 3 Approximately 72 kg / m 3 For example, approximately 40 kg / m 3 Approximately 75 kg / m 3 For example, approximately 40 kg / m 3 Approximately 72 kg / m 3 .

[0143] In one embodiment, the blowing agent may comprise a gaseous blowing agent. For example, the blowing agent may comprise both a solid blowing agent and a gaseous blowing agent. Matters relating to the solid blowing agent are as described above.

[0144] The gaseous foaming agent may contain nitrogen.

[0145] The gaseous blowing agent can be injected using a predetermined injection line during the mixing of the urethane-based prepolymer, the solid blowing agent, and the curing agent. The injection rate of the gaseous blowing agent can be from about 0.8 L / min to about 2.0 L / min, for example, from about 0.8 L / min to about 1.8 L / min, for example, from about 0.8 L / min to about 1.7 L / min, for example, from about 1.0 L / min to about 2.0 L / min, for example, from about 1.0 L / min to about 1.8 L / min, for example, from about 1.0 L / min to about 1.7 L / min.

[0146] The composition used to prepare the polished variable layer may also contain other additives such as surfactants and reaction rate modifiers. The names "surfactant," "reaction rate modifier," etc., are arbitrarily chosen based on the primary function of the respective substance and do not imply that each substance only performs the function defined by its name.

[0147] There are no particular limitations on the surfactant, as long as it is a substance that prevents the aggregation or overlapping of pores. For example, the surfactant may include silicone-based surfactants.

[0148] Based on 100 parts by weight of the urethane-based prepolymer, the surfactant can be used at a content of about 0.2 parts by weight to about 2 parts by weight. Specifically, based on 100 parts by weight of the urethane-based prepolymer, the surfactant content 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 5, 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. When the surfactant is used at a content within the aforementioned range, pores originating from the gas blowing agent can be stably formed and maintained within the cured mold.

[0149] The reaction rate regulator, as a regulator that promotes or delays the reaction, can be used as a reaction promoter, a reaction delayer, or both, depending on the intended use.

[0150] The reaction rate regulator may include a reaction promoter. For example, the reaction promoter may include one selected from the group consisting of tertiary amine compounds, organometallic compounds, and combinations thereof.

[0151] Specifically, the reaction rate regulator may comprise a subset selected from triethylenediamine, dimethylethanolamine, tetramethylbutanediamine, 2-methyl-triethylenediamine, dimethylcyclohexylamine, triethylamine, triisopropanolamine, 1,4-diazabicyclo(2,2,2)octane, bis(2-methylaminoethyl) ether, trimethylaminoethylethanolamine, N,N,N,N,N”-pentamethyldiethylenetriamine, dimethylaminoethylamine, dimethylaminopropylamine, benzyldimethylamine, N-ethylmorpholine, N,N-dimethyl... The reaction rate regulator may be selected from the group consisting of aminoethylmorpholine, N,N-dimethylcyclohexylamine, 2-methyl-2-azanorbornene, dibutyltin dilaurate, stannous octanoate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin maleate, dibutyltin bis(2-ethylhexanoate), and dibutyltin dithiol, and combinations thereof. In one embodiment, the reaction rate regulator may comprise one selected from the group consisting of benzyldimethylamine, N,N-dimethylcyclohexylamine, and triethylamine, and combinations thereof.

[0152] Based on 100 parts by weight of the urethane-based prepolymer, the amount of the reaction rate regulator can be from about 0.05 parts by weight to about 2 parts by weight. Specifically, based on 100 parts by weight of the urethane-based prepolymer, the amount of the reaction rate regulator can be from about 0.05 parts by weight to about 1.8 parts by weight, for example, from about 0.05 parts by weight to about 1.7 parts by weight, for example, from about 0.05 parts by weight to about 1.6 parts by weight, for example, from about 0.1 parts by weight to about 1.5 parts by weight, for example, from about 0.1 parts by weight to about 0.3 parts by weight, for example, from about 0.2 parts by weight to about 1.8 parts by weight, for example, from about 0.2 parts by weight to about 1.7 parts by weight, for example, from about 0.2 parts by weight to about 1.6 parts by weight, for example, from about 0.2 parts by weight to about 1.5 parts by weight, for example, from about 0.5 parts by weight to about 1 part by weight. When the reaction rate regulator is used within the above-mentioned content range, the curing reaction rate of the second composition can be adjusted, thereby facilitating the polishing variable layer with desired pore size and hardness.

[0153] Since the polishing variable layer 101 contains a cured product of the pre-composition derived from appropriately selected compounds, polishing variability corresponding to the values ​​of Formulas 1 to 3 can be achieved, and when the polishing performance of the polishing pad as a whole is achieved together with other layered structures such as the polishing invariant layer 102, improved polishing results can be derived by imparting appropriate physical / mechanical properties.

[0154] As described above, the polishing-invariant layer 102 can be made of a different material than the polishing-variable layer 101. For example, the polishing-invariant layer 102 may contain a thermoplastic resin. Unlike the polishing-variable layer 101 containing a thermosetting resin, when the polishing-invariant layer 102 contains a thermoplastic resin, the laminated structure of the polishing-variable layer 101 and the polishing-invariant layer 102 is more conducive to achieving the desired physical / mechanical properties, and by improving the recyclability of a portion of the polishing pad 110 structure, not only can the original polishing performance be obtained, but also the environmental friendliness can be improved.

[0155] The thermoplastic resin may comprise one selected from the group consisting of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), thermoplastic polyurethane (TPU), and combinations thereof.

[0156] In one embodiment, the thermoplastic resin may comprise thermoplastic polyurethane (TPU). The TPU is not particularly limited and may comprise reaction products such as aromatic isocyanate components and polyol components.

[0157] The aromatic isocyanate component may 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, tolidinediisocyanate, 4,4'-diphenylmethanediisocyanate, and combinations thereof.

[0158] The polyol compound may include one selected from the group consisting of polyether polyol, polyester polyol, polycarbonate polyol, acrylic polyol, and combinations thereof.

[0159] The polyol component of the thermoplastic resin may not contain alcohol compounds having three or more hydroxyl groups (-OH) per molecule. Alternatively, the polyol component of the thermoplastic resin may consist of ethylene glycol or diol compounds having two hydroxyl groups (-OH) per molecule.

[0160] The weight-average molecular weight (Mw) of the polyol component of the thermoplastic resin can be from about 80 g / mol to about 1000 g / mol, for example, from about 90 g / mol to about 800 g / mol.

[0161] The polyol compound may comprise one of the following groups: polytetramethylene ether glycol (PTMG), 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, and combinations thereof.

[0162] In one embodiment, the thermoplastic resin may comprise a reaction product of the composition, which, relative to 100 parts by weight of the aromatic isocyanate component, comprises about 80 parts by weight to about 130 parts by weight, for example, about 80 parts by weight to about 125 parts by weight, for example, about 85 parts by weight to about 120 parts by weight of the polyol component.

[0163] In one embodiment, the aromatic isocyanate component may include 4,4'-diphenylmethanediisocyanate, and the polyol component may include 1,4-butanediol and polytetramethylene ether diol (PTMG).

[0164] For example, the thermoplastic resin may comprise the reaction product of the composition, which, relative to 10 parts by weight to about 30 parts by weight, for example, about 10 parts by weight to about 25 parts by weight, for example, about 12 parts by weight to about 20 parts by weight, of the 1,4-butanediol, is contained in relation to 100 parts by weight of the 4,4'-diphenylmethanediisocyanate.

[0165] For example, the thermoplastic resin may comprise the reaction product of the composition, which, relative to 100 parts by weight of the 4,4'-diphenylmethanediisocyanate, comprises about 70 parts by weight to about 120 parts by weight, for example, more than about 70 parts by weight and less than about 120 parts by weight of the polytetramethylene ether diol (PTMG).

[0166] As described above, in the polished layer 10, the ratio of the Shore D hardness of the variable polished layer 101 to the constant polished layer 102 can be from about 0.50 to about 1.50. Figure 1 This schematically illustrates the case where the separable interface 13 between the first surface 11 and the second surface 12 is a single entity. Referring to this, the ratio of the Shore D hardness of two adjacent layers 101 and 102, namely the variable polishing layer 101 and the constant polishing layer 102, with reference to the separable interface 13, can be from 0.50 to about 1.50. The Shore D hardness ratio can be, for example, from about 0.50 to about 1.50, for example, from about 0.60 to about 1.50, for example, from about 0.70 to about 1.40, for example, from about 0.80 to about 1.20. By satisfying the aforementioned material properties and this hardness ratio, the variable polishing layer 101 and the constant polishing layer 102 can transmit appropriate elasticity and rigidity to the polishing object through the first surface 11, thus more effectively achieving the desired polishing performance.

[0167] Figure 3 A cross-section of the polishing pad 110 in one implementation example is schematically shown. (Refer to...) Figure 3 The polishing pad 110 may also include a buffer layer 20 on one surface of the polishing layer 10. In this case, the second surface 12 of the polishing layer 10 can be used as an adhesion surface for the buffer layer 20.

[0168] The buffer layer 20 is a layer that imparts shock absorption properties to the polishing pad 110, and its Asker C hardness can be from about 65 to about 75, for example, from about 70 to about 75. In one implementation, the ratio Hc / Hp of the buffer layer 20 to the Asker C hardness Hc of the polishing layer 10 with its Shore D hardness Hp can be from about 1.00 to about 1.55, for example, from about 1.25 to about 1.55, for example, from about 1.27 to about 1.55.

[0169] Considering the semiconductor device fabrication method described later, when the surface of the semiconductor substrate to be polished is in direct or indirect contact with the first surface 11, which is the polishing surface of the polishing layer 10, and the polishing process is performed, the specified pressure conditions can be applied according to the polishing purpose. The buffer layer 20 imparts appropriate elasticity in the thickness direction of the polishing pad 110 to minimize defects such as scratches on the surface to be polished during the polishing process under such pressure conditions, and helps to greatly improve the polishing flatness of the surface to be polished. This technical effect can be maximized when the ratio of the Shore D hardness of the polishing layer 10 to the Asker C hardness of the buffer layer 20 meets the above-mentioned range.

[0170] The buffer layer 20 may include non-woven fabric or suede, but is not limited to these.

[0171] In one implementation, the buffer layer 20 may include a nonwoven fabric. The term "nonwoven fabric" refers to a three-dimensional mesh structure without woven fibers. Specifically, the buffer layer 20 may include a nonwoven fabric and a resin impregnated in the nonwoven fabric.

[0172] The nonwoven fabric may be, for example, a nonwoven fabric comprising fibers selected from the group consisting of polyester fibers, polyamide fibers, polypropylene fibers, polyethylene fibers, and combinations thereof.

[0173] The resin impregnated in the nonwoven fabric may be, for example, one selected from the group consisting of polyurethane resin, polybutadiene resin, styrene-butadiene copolymer resin, styrene-butadiene-styrene copolymer resin, acrylonitrile-butadiene copolymer resin, styrene-ethylene-butadiene-styrene copolymer resin, silicone rubber resin, polyester elastomer resin, polyamide elastomer resin, and combinations thereof.

[0174] In one implementation, the buffer layer 20 may comprise a nonwoven fabric comprising polyester fibers, wherein a resin comprising polyurethane resin is impregnated in the polyester fibers.

[0175] In one implementation, the thickness of the buffer layer 20 may be from about 0.5 mm to about 2.5 mm, for example, from about 0.8 mm to about 2.5 mm, for example, from about 1.0 mm to about 2.5 mm, for example, from about 1.0 mm to about 2.0 mm, for example, from about 1.0 mm to about 1.8 mm.

[0176] Reference Figure 3 According to one embodiment, the polishing pad 110 may further include a first adhesive layer 30 for attaching the polishing layer 10 and the buffer layer 20. For example, the first adhesive layer 30 may include a heat-sealing adhesive. Specifically, the first adhesive layer 30 may contain, but is not limited to, one selected from the group consisting of polyurethane-based adhesives, silicone adhesives, acrylic adhesives, and combinations thereof.

[0177] Reference Figure 3 The polishing pad 110 may further include a second adhesive layer 40 for attaching a surface plate. The second adhesive layer 40 is a medium layer for attaching the polishing pad 110 and the surface plate of the polishing apparatus, and may be derived from, for example, a pressure-sensitive adhesive (PSA), but is not limited thereto.

[0178] Relative to the overall laminate, the Shore D hardness of the polished surface of the polishing pad 110 can be from about 45 to about 70, for example, from about 45 to about 65, for example, greater than about 45 and less than about 65, for example, from about 50 to about 60. The hardness range described above is achieved comprehensively through the combination of each layer constituting the polishing pad 110, thereby minimizing defects such as scratches on the polished surface and contributing to improved polishing flatness.

[0179] The ratio Ht / Hp of the Shore D hardness Ht of the overall laminate of the polishing pad 110 to the Shore D hardness Hp of the polishing layer 10 can be from about 0.95 to about 1.10, for example, from about 0.96 to about 1.10, or from about 0.98 to about 1.10. The polishing layer 10 is the layer in the overall structure of the polishing pad 110 that directly affects the polishing performance. When the Shore D hardness of the polishing layer 10 itself and the Shore D hardness achieved by the polishing pad 110 as a whole have the aforementioned relative ratio, it is more conducive to achieving the target polishing performance.

[0180] In one implementation, the compression ratio of the polishing pad 110 can be from about 0.4% to about 2.0%, for example, from about 0.6% to about 1.6%, for example, from about 0.8% to about 1.5%, for example, from about 1.0% to about 1.5%. As described above, the polishing pad 110 can achieve the compression ratio in the range of the above range through a subdivided structural design in the thickness direction, and the corresponding elastic force is transferred to the polished surface through the first surface 11, thereby achieving the advantage of maximizing defect prevention performance.

[0181] The method for preparing the polishing pad 110 will be described below.

[0182] The polishing pad 110 is prepared by the following method: the method includes the step of preparing a polishing layer 10, the polishing layer 10 including a first surface 11 as a polishing surface, a second surface 12 as the back 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 preparing the polishing layer 10 includes: preparing at least one polishing variable layer 101, the polishing variable layer 101 being a region from the first surface 11 to the separable interface 13; preparing at least one polishing invariant layer 102, the polishing invariant layer 102 being a region from the separable interface 13 to the second surface 12; and stacking the polishing variable layer 101 and the polishing invariant layer 102, wherein the separable interface 13 is used as the stacking interface, and the polishing pad 101 and the polishing invariant layer 102 can be prepared by a preparation method in which the ratio of their respective Shore D hardness is about 0.50 to about 1.50.

[0183] The descriptions of the polishing variable layer 101, the polishing constant layer 102, and the separable interface 103 are all the same as those for the polishing pad 110 described above.

[0184] The step of laminating the variable polishing layer 101 and the constant polishing layer 102 can be a step of laminating with a double-sided adhesive. The double-sided adhesive is not particularly limited as long as it can bond to each other, and may include one selected from the group consisting of polyurethane-based adhesives, silicone adhesives, acrylic adhesives, and combinations thereof. Thus, the lamination interface of the variable polishing layer 101 and the constant polishing layer 102 can serve as the separable interface 13.

[0185] The steps for preparing the polished variable layer 101 may include: preparing a first composition comprising a urethane-based prepolymer; preparing a second composition comprising the first composition, a foaming agent, and a curing agent; and curing the second composition.

[0186] The description of the urethane-based prepolymer is the same as that of the polishing pad 110 above, and the first composition is the same as the composition of the prepolymer described above regarding the polishing pad 110. All matters therein are the same as those described above.

[0187] The viscosity of the first composition can be from about 100 cps to about 1000 cps at about 80°C, for example, from about 200 cps to about 800 cps, for example, from about 200 cps to about 600 cps, for example, from about 200 cps to about 550 cps, for example, from about 300 cps to about 500 cps. Meeting this viscosity range improves the efficiency of the preparation process of the polishing variable layer 101 and enhances the dispersibility of other components. As a result, the polishing variable layer 101 can better ensure appropriate hardness and density.

[0188] The matters concerning the foaming agent and the curing agent are the same as those concerning the polishing pad 110.

[0189] When the foaming agent includes a solid foaming agent, the step of preparing the second composition may include: preparing the first-1 composition by mixing the first composition and the solid foaming agent; and preparing the second composition by mixing the first-1 composition and the curing agent.

[0190] The viscosity of the first-1 composition can be from about 1000 cps to about 2000 cps at about 80°C, for example, from about 1000 cps to about 1800 cps, for example, from about 1000 cps to about 1600 cps, for example, from about 1000 cps to about 1500 cps. Because the viscosity of the first-1 composition meets such a range, it is advantageous in aspects similar to the technical significance of the viscosity of the first composition.

[0191] When the foaming agent includes a gaseous foaming agent, the step of preparing the second composition may include: preparing the first-second composition by mixing the first composition and the curing agent; and preparing the second composition by injecting the gaseous foaming agent into the first-second composition.

[0192] In one implementation, the first and second compositions may further include a solid foaming agent.

[0193] For example, the injection rate of the gaseous foaming agent can be from about 0.8 L / min to about 2.0 L / min, for example, from about 0.8 L / min to about 1.8 L / min, for example, from about 0.8 L / min to about 1.7 L / min, for example, from about 1.0 L / min to about 2.0 L / min, for example, from about 1.0 L / min to about 1.8 L / min, for example, from about 1.0 L / min to about 1.7 L / min.

[0194] In one implementation, the step of curing the second composition may include: preparing a mold preheated to a first temperature; injecting the second composition into the preheated mold and curing it; and post-curing the cured second composition at a second temperature higher than the first temperature.

[0195] In one implementation, the temperature difference T2-T1 between the first temperature T1 and the second temperature T2 can be from about 10°C to about 40°C, for example, from about 10°C to about 35°C, for example, from about 15°C to about 35°C.

[0196] In one implementation, the first temperature can be from about 60°C to about 100°C, for example, from about 65°C to about 95°C, or from about 70°C to about 90°C. In one implementation, the second temperature can be from about 100°C to about 130°C, for example, from about 100°C to 125°C, or from about 100°C to about 120°C.

[0197] As described above, applying multi-stage temperature conditions during the curing of the second composition may be more beneficial for ensuring the target's physical / mechanical properties, such as hardness, tensile strength, and elongation, in the polished variable layer 101 prepared by this method.

[0198] In the step of curing the second composition, the step of injecting the second composition into the preheated mold and curing it 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.

[0199] The post-curing step of the cured second composition under a second temperature condition 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.

[0200] The method for preparing the polishing pad 110 may further include the step of processing the first surface 11.

[0201] The steps of machining the first surface 11 may include at least one of the following steps: step 1, forming a groove on the first surface 11; step 2, line turning the first surface 11; and step 3, roughening the first surface 11.

[0202] In step 1, the groove may include at least one of the following: concentric circular grooves formed at predetermined intervals from the center to the edge of the polished variable layer 101 on the first surface 11; and radial grooves formed continuously from the center to the edge of the polished variable layer 101 on the first surface 11.

[0203] In step 2, the line turning can be performed by using a cutting tool to cut the first surface 11 to a specified thickness.

[0204] In step 3, the roughening can be performed by processing the first surface 11 with a sanding roller.

[0205] The steps for preparing the polishing-invariant layer 102 may include: preparing a thermoplastic resin raw material; and processing the thermoplastic resin raw material.

[0206] The thermoplastic resin raw material may include one selected from the group consisting of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), thermoplastic polyurethane (TPU), and combinations thereof.

[0207] In one embodiment, the thermoplastic resin raw material may comprise a composition for preparing thermoplastic polyurethane (TPU). The TPU preparation composition is not particularly limited and may include reaction products such as aromatic isocyanate components and polyol components.

[0208] The aromatic isocyanate component may 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, tolidinediisocyanate, 4,4'-diphenylmethanediisocyanate, and combinations thereof.

[0209] The polyol compound may include one selected from the group consisting of polyether polyol, polyester polyol, polycarbonate polyol, acrylic polyol, and combinations thereof.

[0210] The polyol component of the thermoplastic resin raw material may not contain alcohol compounds having three or more hydroxyl groups (-OH) per molecule. Alternatively, the polyol component of the thermoplastic resin raw material may consist of ethylene glycol or diol compounds having two hydroxyl groups (-OH) per molecule.

[0211] The weight-average molecular weight (Mw) of the polyol component in the thermoplastic resin raw material can be from about 80 g / mol to about 1000 g / mol, for example, from about 90 g / mol to about 800 g / mol.

[0212] The polyol compound may comprise one of the following groups: polytetramethylene ether glycol (PTMG), 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, and combinations thereof.

[0213] In one embodiment, the thermoplastic resin raw material may contain about 80 parts by weight to about 130 parts by weight, for example, about 80 parts by weight to about 80 parts by weight to about 125 parts by weight, for example, about 85 parts by weight to about 120 parts by weight, relative to 100 parts by weight of the aromatic isocyanate component.

[0214] In one embodiment, the aromatic isocyanate component may include 4,4'-diphenylmethane diisocyanate, and the polyol component may include 1,4-butanediol and polytetramethylene ether diol (PTMG).

[0215] For example, relative to 100 parts by weight of the 4,4'-diphenylmethanediisocyanate, the thermoplastic resin raw material may contain about 10 parts by weight to about 30 parts by weight, for example, about 10 parts by weight to about 25 parts by weight, for example, about 12 parts by weight to about 20 parts by weight of the 1,4-butanediol.

[0216] For example, relative to 100 parts by weight of the 4,4'-diphenylmethane diisocyanate, the thermoplastic resin raw material may contain about 70 parts by weight to about 100 parts by weight of the polytetramethylene ether diol (PTMG).

[0217] In one embodiment, the step of processing the thermoplastic resin raw material may include: injecting the thermoplastic resin raw material into a mold preheated to about 70°C to about 90°C and curing it for about 80 minutes to about 160 minutes; post-curing the cured thermoplastic resin raw material at room temperature of about 20°C to about 40°C; and aging the post-cured thermoplastic resin raw material at about 100°C to about 120°C for about 10 hours to about 15 hours.

[0218] The preheating temperature of the mold can be, for example, about 70°C to about 90°C, or about 75°C to about 85°C, and the curing time can be, for example, about 80 minutes to about 160 minutes, or about 100 minutes to about 150 minutes, or about 100 minutes to about 130 minutes, or about 110 minutes to about 130 minutes.

[0219] In the step of maturing the thermoplastic resin raw material, the temperature can be from about 100°C to about 120°C, for example, from about 105°C to about 115°C, and the time can be from about 10 hours to about 15 hours, for example, from about 10 hours to about 14 hours, for example, from about 10 hours to about 13 hours, for example, from about 11 hours to about 13 hours.

[0220] As described above, by applying the laminate of the variable polishing layer 101 and the constant polishing layer 102 to the polishing layer 10, the advantages of precise design of various physical properties in the thickness direction of the polishing layer 10 can be ensured, and excellent polishing performance can be provided to the polished surface of the object through the first surface 11 of the variable polishing layer 101.

[0221] The method for preparing the polishing pad 110 may further include the step of stacking a buffer layer 20 on the second surface 12 of the polishing layer 10. Matters concerning the buffer layer 20 are the same as those described above regarding the polishing pad 110.

[0222] In one implementation, the step of laminating the buffer layer 20 may include: applying a hot melt adhesive to the second surface 12; applying a hot melt adhesive to one surface of the buffer layer 20; laminating the second surface 12 and the buffer layer 20 in such a manner that the surfaces coated with the hot melt adhesive are in contact with each other; and performing welding under pressure or heating conditions.

[0223] The hot melt adhesive is not particularly limited and may include one selected from the group consisting of polyurethane-based adhesives, silicone adhesives, acrylic adhesives, and combinations thereof.

[0224] Reference Figure 3 During the stacking process of the buffer layer 20, the first adhesive layer 30 may be formed on the second surface 12.

[0225] In one embodiment, the method for preparing the polishing pad 110 may further include the step of forming a second adhesive layer 40 on a surface of the buffer layer 20. The second adhesive layer 40 is an element for attaching the polishing pad 110 to the surface plate of the polishing apparatus, and may be derived from, for example, a pressure-sensitive adhesive (PSA), but is not limited thereto.

[0226] Specifically, in one implementation, the step of forming the second adhesive layer 40 may include: applying a pressure-sensitive adhesive to the second surface 12 of the buffer layer 20 and the opposite surface; and drying the pressure-sensitive adhesive.

[0227] In another embodiment, the step of forming the second adhesive layer 40 may include: preparing an adhesive film comprising a pressure-sensitive adhesive; and attaching the adhesive film to the second surface 12 of the buffer layer 20 and the opposite surface.

[0228] The polishing pad can be used in polishing processes for various purposes. For example, it can be applied to the fabrication of semiconductor devices. Recently, the required integration density of semiconductor devices has been increasing, and their structures have become more complex in three dimensions. To meet these requirements, precise process control is essential in the fabrication of semiconductor devices. Semiconductor devices comprise thin films of various materials and shapes, and polishing processes requiring precise adjustments to process conditions are needed depending on the material and shape of each thin film. The polishing pad, as one of the elements of this precise process control, can produce drastically different polishing results for the semiconductor device depending on even slight differences in its structure, material, and shape.

[0229] As described above, the polishing constant layer 102 is a region whose physical and / or chemical properties remain essentially unchanged during the polishing process. Although it does not directly affect the polished surface of the polishing object, it is stacked with the polishing variable layer 101 and ensures that the polishing pad has appropriate overall structural support performance, elasticity, elongation and tensile strength, etc., so it can be used as a structure that directly or indirectly affects the final polishing performance.

[0230] In this respect, the polishing invariant layer 102 can maximize its technical advantages by being a cured product comprising thermosetting polyurethane particles and a composition comprising an adhesive (binder).

[0231] In one implementation, the average particle size of the thermosetting polyurethane particles can be from about 20 μm to about 3.0 mm. For example, the particle size of the thermosetting polyurethane particles can be from about 50 μm to about 2.0 mm, for example, from about 100 μm to about 2.0 mm, for example, from about 500 μm to about 2.0 mm. The “average particle size” is a numerical average of the diameters measured based on the cross-section of the particles, which can be obtained from a two-dimensional projection image of the particles. There are no particular limitations on the method of obtaining the projection image, which can be obtained by using, for example, a scanning electron microscope (SEM) or a transmission electron microscope (TEM). By applying particles of this size, the support rigidity of the polishing invariant layer 102 can be improved, and it may help ensure the long-term durability of the polishing variable layer 101.

[0232] In one implementation, the thermosetting polyurethane particles can be particles derived from waste polishing pads containing thermosetting polyurethane. Specifically, the thermosetting polyurethane particles can be derived from the pulverized product of polishing pad waste containing thermosetting polyurethane. "Waste polishing pads" refers to polishing pads discarded after use in the desired polishing process or byproducts discarded during polishing pad preparation. Generally, polishing pads are semi-permanent process components, and because their physical structure and / or chemical properties no longer meet polishing requirements after a specified period of application in the polishing process, they are among the components that need to be replaced. Furthermore, since polishing pads need to provide a polished surface that meets the polishing purpose, only a portion that ensures the quality stability of the polished object is used during their preparation, with the remainder mostly discarded as byproducts. Thus, when used polishing pads or byproducts discarded during preparation contain thermosetting polyurethane, they become a major culprit of environmental pollution due to the virtually nonexistent possibility of recycling. Moreover, with the increasing demand for semiconductors in recent years, the number of polishing pads discarded after use in semiconductor processes and other applications has been continuously increasing, thus exacerbating this environmental pollution problem. Therefore, when the polishing pad is used as a structure of the polishing invariant layer 102, and particles derived from the waste material of the polishing pad are applied, since it is waste material from an article used for the same purpose, it may be more conducive to achieving the above-mentioned technical objectives while achieving environmental protection effects.

[0233] The composition used to form the polish-resistant layer may include the thermosetting polyurethane particles and an adhesive (binder).

[0234] In one implementation, the adhesive may include a first urethane-based prepolymer and a first curing agent. While ensuring uniform dispersion of the thermosetting polyurethane particles, the adhesive ensures that the polishing-invariant layer has appropriate physical properties compared to the polishing-variable layer, thereby enabling optimized polishing performance throughout the polishing layer.

[0235] The first urethane-based prepolymer may comprise the reaction product of a first isocyanate compound and a first polyol compound. In the first urethane-based prepolymer, the term "prepolymer" refers to a polymer with a low molecular weight whose degree of polymerization stops at an intermediate stage to facilitate molding during the cured product preparation process. The prepolymer itself undergoes additional curing processes such as heating and / or pressurization, or is mixed with another polymerizable compound, such as a heterogeneous monomer or an additional compound of the heterogeneous prepolymer, and then reacted before being molded into the final cured product.

[0236] The first isocyanate compound may be selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and combinations thereof. For example, the isocyanate compound may contain aromatic diisocyanates. For example, the isocyanate compound may contain both aromatic diisocyanates and alicyclic diisocyanates.

[0237] The first isocyanate compound may comprise, for example, selected from 2,4-toluenediisocyanate (2,4-TDI), 2,6-toluenediisocyanate (2,6-TDI), naphthalene-1,5-diisocyanate, p-phenylenediisocyanate, tolidinediisocyanate, 4,4'-diphenylmethanediisocyanate, hexamethylenediisocyanate, dicyclohexylmethanediisocyanate, and 4,4'-dicyclohexylmethanediisocyanate. 12 MDI, isophorone diisocyanate, and combinations thereof constitute one of the groups.

[0238] In the first polyol compound, the term "polyol" refers to a compound containing at least two hydroxyl groups (-OH) in its molecule. In one embodiment, the polyol compound may comprise a diol compound having two hydroxyl groups, i.e., a diol or glycol, or a triol compound having three hydroxyl groups, i.e., a triol compound.

[0239] The first polyol compound may comprise one of the groups selected from polyether polyol, polyester polyol, polycarbonate polyol, acrylic polyol, and combinations thereof.

[0240] The first polyol compound may comprise one of the following groups: polytetramethylene ether glycol (PTMG), 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 triol, and combinations thereof.

[0241] The weight-average molecular weight (Mw) of the first polyol compound can be from about 100 g / mol to about 3000 g / mol, for example, from about 100 g / mol to about 2000 g / mol, for example, from about 100 g / mol to about 1800 g / mol.

[0242] In one embodiment, the first polyol compound may comprise a low molecular weight polyol with a weight-average molecular weight (Mw) of about 100 g / mol and less than about 300 g / mol, and a high molecular weight polyol with a weight-average molecular weight (Mw) of about 300 g / mol and less than about 1800 g / mol. The weight-average molecular weight (Mw) of the high molecular weight polyol may, for example, be about 500 g / mol and less than about 1800 g / mol, or, for example, about 700 g / mol and less than about 1800 g / mol. In this case, the first polyol compound can form a suitable crosslinking structure in the first urethane-based prepolymer, and the adhesive comprising the first urethane-based prepolymer can further enhance the support properties and elasticity of the polishing-resistant layer.

[0243] The weight-average molecular weight (Mw) of the first urethane-based prepolymer can be from about 500 g / mol to about 3000 g / mol, for example, from about 600 g / mol to about 2000 g / mol, or from about 800 g / mol to about 1000 g / mol. When the first urethane-based prepolymer has a degree of polymerization corresponding to the above-mentioned weight-average molecular weight (Mw), it is more advantageous for the adhesive to improve the dispersibility of the thermosetting polyurethane particles in the polishing-invariant layer.

[0244] In one implementation, the first isocyanate compound may comprise an aromatic diisocyanate. For example, the aromatic diisocyanate may comprise 2,4-toluene diisocyanate (2,4-TDI), specifically, it may comprise both 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI). Alternatively, for example, the first polyol compound may comprise polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

[0245] In another implementation, the first isocyanate compound may comprise an aromatic diisocyanate and an alicyclic diisocyanate. For example, the aromatic diisocyanate may comprise 2,4-toluene diisocyanate (2,4-TDI), specifically, it may comprise both 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI). For example, the alicyclic diisocyanate may comprise 4,4'-dicyclohexylmethane diisocyanate (H... 12 MDI). Alternatively, for example, the first polyol compound may comprise polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

[0246] In one implementation, the total weight of the first polyol compound may be from about 100 parts by weight to about 180 parts by weight relative to 100 parts by weight of the first isocyanate compound. For example, it may be greater than about 100 parts by weight and less than about 180 parts by weight, for example, it may be from about 110 parts by weight to about 160 parts by weight, for example, it may be from about 120 parts by weight to about 150 parts by weight.

[0247] In another embodiment, the total weight of the first polyol compound may be greater than about 180 parts by weight and less than about 250 parts by weight relative to 100 parts by weight of the first isocyanate compound, for example, it may be about 185 parts by weight to about 250 parts by weight, for example, it may be about 190 parts by weight to about 240 parts by weight.

[0248] In one embodiment, the first polyol compound comprises polytetramethylene ether glycol (PTMG), and the content of PTMG relative to 100 parts by weight of the first isocyanate compound can be from about 100 parts by weight to about 250 parts by weight, for example, it can be greater than about 100 parts by weight and less than about 250 parts by weight, for example, it can be from about 110 parts by weight to about 220 parts by weight, for example, it can be from about 110 parts by weight to about 140 parts by weight.

[0249] In another embodiment, the first polyol compound comprises polytetramethylene ether glycol (PTMG), and the content of PTMG may be from about 150 parts by weight to about 250 parts by weight, for example, from about 180 parts by weight to about 230 parts by weight, relative to 100 parts by weight of the first isocyanate compound.

[0250] In one embodiment, the first polyol compound comprises diethylene glycol (DEG), and the content of the diethylene glycol (DEG) may be from about 1 part by weight to about 20 parts by weight, for example, from about 1 part by weight to about 15 parts by weight, relative to 100 parts by weight of the first isocyanate compound.

[0251] In one embodiment, the first isocyanate compound comprises the aromatic diisocyanate, which comprises 2,4-TDI and 2,6-TDI, wherein the content of 2,6-TDI may be from about 1 part by weight to about 40 parts by weight relative to 100 parts by weight, for example, from about 1 part by weight to about 30 parts by weight, for example, from about 3 parts by weight to about 28 parts by weight, for example, from about 20 parts by weight to about 30 parts by weight.

[0252] In another embodiment, the content of 2,6-TDI may be from about 1 part by weight to about 40 parts by weight relative to 100 parts by weight of the 2,4-TDI, for example, from about 1 part by weight to about 30 parts by weight, for example, from about 1 part by weight to about 20 parts by weight, for example, from about 1 part by weight to about 10 parts by weight.

[0253] In one embodiment, the first isocyanate compound comprises the aromatic diisocyanate and the alicyclic diisocyanate, wherein the content of the alicyclic diisocyanate may be from about 5 parts by weight to about 30 parts by weight relative to the total 100 parts by weight of the aromatic diisocyanate, for example, from about 10 parts by weight to about 25 parts by weight.

[0254] When the first urethane-based prepolymer meets the above-described compositional characteristics, the adhesive can achieve excellent dispersibility of the thermosetting polyurethane particles. Furthermore, since the thermosetting polyurethane particles and the adhesive are firmly bonded to each other at their interface, it is more beneficial to ensure the overall support rigidity and elasticity of the polished, non-refined layer.

[0255] The adhesive may contain a first curing agent. The first curing agent, through a chemical reaction with the first urethane-based prepolymer and the formation of a suitable crosslinking structure, is able to simultaneously ensure, at appropriate levels, excellent dispersibility of the thermosetting polyurethane particles and appropriate mechanical rigidity of the polish-resistant layer.

[0256] In one embodiment, the first curing agent may comprise a compound containing a reactive group selected from the group consisting of amine (-NH2), alcohol (-OH), and combinations thereof. The "reactive group" refers to a terminal functional group that directly participates in the chemical reaction when the first curing agent reacts with a heterogeneous compound such as the first urethane prepolymer. That is, the first curing agent may comprise, for example, a compound containing an amine (-NH2) group as a reactive group in one molecule, or a compound containing an alcohol (-OH) group as a reactive group in one molecule, or a compound containing both an amine (-NH2) group and an alcohol (-OH) group as reactive groups in one molecule.

[0257] For example, the first curing agent may comprise a compound selected from 4,4'-methylenebis(2-chloroaniline) (MOCA), diethyltoluenediamine (DETDA), diaminodiphenylmethane, dimethylthio-toluenediamine (DMTDA), and propanediol bis(p-aminobenzoate). One of the following groups: bisp-aminobenzoate, methylenebis-methylanthranilate, diaminodiphenylsulfone, m-xylylenediamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, bis(4-amino-3-chlorophenyl)methane, triethanolamine, tripropanolamine, triisopropanolamine, and combinations thereof.

[0258] The content of the first curing agent in the total 100% by weight of the adhesive can be from about 15% by weight to about 30% by weight, for example, from about 18% by weight to about 27% by weight, for example, from about 19% by weight to about 26% by weight, for example, from about 20% by weight to about 26% by weight. By using the first curing agent in such a content, it is more advantageous to achieve the technical performance of the adhesive.

[0259] Relative to 100 parts by weight of the adhesive, the composition for forming the polish-resistant layer may contain about 15 parts by weight to about 150 parts by weight of the thermosetting polyurethane particles, for example, about 20 parts by weight to about 120 parts by weight, or about 40 parts by weight to about 110 parts by weight. Since the relative content ratio of the adhesive and the thermosetting polyurethane particles satisfies the above range, the thermosetting polyurethane particles can be uniformly dispersed and firmly bonded to the polish-resistant layer, thereby contributing to improved overall durability.

[0260] Depending on the requirements, the composition used to form the polish-resistant layer may further include a first foaming agent. The first foaming agent can be used to adjust the density and elasticity by imparting a porous structure to the polish-resistant layer. For example, the first foaming agent may comprise one selected from the group consisting of solid foaming agents, gaseous foaming agents, liquid foaming agents, and combinations thereof.

[0261] When the composition used to form the polishing-invariant layer includes the first foaming agent, it may contain about 0.1 parts by weight to about 10 parts by weight of the first foaming agent relative to 100 parts by weight of the thermosetting polyurethane particles.

[0262] Unlike the constant polishing layer 102, the variable polishing layer 101 may be a region that does not contain the thermosetting polyurethane particles. That is, the variable polishing layer 101 may be a region that does not contain the thermosetting polyurethane particles. In the aspect of having the thermosetting polyurethane particles, by constructing the variable polishing layer 101 differently from the constant polishing layer 102, the physical properties of the polishing pad 110 in the thickness direction can be more precisely subdivided, thereby enabling various polishing performances for various applications and purposes.

[0263] In one implementation, the polished variable layer 101 may comprise a cured composition containing a second urethane-based prepolymer. In the second urethane-based prepolymer, the term "prepolymer" refers to a polymer with a low molecular weight whose degree of polymerization stops at an intermediate stage to facilitate molding during the cured product preparation process. The prepolymer itself undergoes additional curing processes such as heating and / or pressurization, or is mixed and reacted with another polymerizable compound, such as a heterogeneous monomer or an additional compound of a heterogeneous prepolymer, and then molded into a final cured product.

[0264] In one embodiment, the second urethane-based prepolymer may comprise the reaction product of a second isocyanate compound and a second polyol compound. The second isocyanate compound and the second polyol compound may each comprise the same compounds as the first isocyanate compound and the first polyol compound, or they may comprise different compounds.

[0265] In one implementation, the second isocyanate compound may be selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and combinations thereof. For example, the second isocyanate compound may contain aromatic diisocyanates. For example, the second isocyanate compound may contain both aromatic diisocyanates and alicyclic diisocyanates.

[0266] The second isocyanate compound may include, for example, selected from 2,4-toluenediisocyanate (2,4-TDI), 2,6-toluenediisocyanate (2,6-TDI), naphthalene-1,5-diisocyanate, p-phenylenediisocyanate, tolidinediisocyanate, 4,4'-diphenylmethanediisocyanate, hexamethylenediisocyanate, dicyclohexylmethanediisocyanate, and 4,4'-dicyclohexylmethanediisocyanate. 12 MDI, isophorone diisocyanate, and combinations thereof constitute one of the groups.

[0267] In the second polyol compound, "polyol" refers to a compound containing at least two or more hydroxyl groups (-OH). In one embodiment, the polyol compound may comprise a diol compound having two hydroxyl groups, i.e., a diol or glycol, or a triol compound having three hydroxyl groups, i.e., a triol compound.

[0268] The second polyol compound may include one selected from the group consisting of polyether polyol, polyester polyol, polycarbonate polyol, acrylic polyol, and combinations thereof.

[0269] The second polyol compound may comprise one of the following groups: polytetramethylene ether glycol (PTMG), 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 triol, and combinations thereof.

[0270] The weight-average molecular weight (Mw) of the second polyol compound can be from about 100 g / mol to about 3000 g / mol, for example, from about 100 g / mol to about 2000 g / mol, for example, from about 100 g / mol to about 1800 g / mol.

[0271] In one embodiment, the second polyol compound may comprise a low molecular weight polyol with a weight-average molecular weight (Mw) of about 100 g / mol and less than about 300 g / mol, and a high molecular weight polyol with a weight-average molecular weight (Mw) of about 300 g / mol and less than about 1800 g / mol. The weight-average molecular weight (Mw) of the high molecular weight polyol may, for example, be about 500 g / mol and less than about 1800 g / mol, or, for example, about 700 g / mol and less than about 1800 g / mol. In this case, the second polyol compound can form a suitable crosslinking structure in the second urethane-based prepolymer, resulting in the polishing variable layer 101 exhibiting suitable tensile strength, elongation, and compressive properties, thus further enhancing the polishing performance through the first surface 11.

[0272] The weight-average molecular weight (Mw) of the second urethane-based prepolymer can be from about 500 g / mol to about 3000 g / mol, for example, from about 600 g / mol to about 2000 g / mol, or from about 800 g / mol to about 1000 g / mol. When the second urethane-based prepolymer has a degree of polymerization corresponding to the aforementioned weight-average molecular weight (Mw), the polishing variable layer 101 containing the final cured product exhibits appropriate surface hardness and tensile strength, thus further enhancing the polishing performance through the first surface 11.

[0273] In one implementation, the second isocyanate compound may comprise an aromatic diisocyanate. For example, the aromatic diisocyanate may comprise 2,4-toluene diisocyanate (2,4-TDI), specifically, it may comprise both 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI). Alternatively, for example, the second polyol compound may comprise polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

[0274] In another implementation, the second isocyanate compound may comprise an aromatic diisocyanate and an alicyclic diisocyanate. For example, the aromatic diisocyanate may comprise 2,4-toluene diisocyanate (2,4-TDI), specifically, it may comprise both 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI). For example, the alicyclic diisocyanate may comprise 4,4'-dicyclohexylmethane diisocyanate (H... 12 MDI). Alternatively, for example, the first polyol compound may comprise polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

[0275] In one implementation, the total weight of the second polyol compound relative to 100 parts by weight of the second isocyanate compound can be from about 100 parts by weight to about 180 parts by weight, for example, it can be greater than about 100 parts by weight and less than about 180 parts by weight, for example, it can be from about 110 parts by weight to about 160 parts by weight, for example, it can be from about 120 parts by weight to about 150 parts by weight.

[0276] In another embodiment, the total weight of the second polyol compound relative to 100 parts by weight of the second isocyanate compound may be greater than about 180 parts by weight and less than about 250 parts by weight, for example, it may be about 185 parts by weight to about 250 parts by weight, for example, it may be about 190 parts by weight to about 240 parts by weight.

[0277] In one embodiment, the second polyol compound comprises polytetramethylene ether glycol (PTMG), and the content of PTMG relative to 100 parts by weight of the second isocyanate compound can be from about 100 parts by weight to about 250 parts by weight, for example, it can be greater than about 100 parts by weight and less than about 250 parts by weight, for example, it can be from about 110 parts by weight to about 220 parts by weight, for example, it can be from about 110 parts by weight to about 140 parts by weight.

[0278] In another embodiment, the second polyol compound comprises polytetramethylene ether glycol (PTMG), and the content of PTMG may be from about 150 parts by weight to about 250 parts by weight, for example, from about 180 parts by weight to about 230 parts by weight, relative to 100 parts by weight of the second isocyanate compound.

[0279] In one embodiment, the second polyol compound comprises diethylene glycol (DEG), and the content of diethylene glycol (DEG) may be from about 1 part by weight to about 20 parts by weight, for example, from about 1 part by weight to about 15 parts by weight, relative to 100 parts by weight of the second isocyanate compound.

[0280] In one embodiment, the second isocyanate compound comprises the aromatic diisocyanate, which comprises 2,4-TDI and 2,6-TDI, wherein the content of 2,6-TDI may be from about 1 part by weight to about 40 parts by weight relative to 100 parts by weight, for example, from about 1 part by weight to about 30 parts by weight, for example, from about 3 parts by weight to about 28 parts by weight, for example, from about 20 parts by weight to about 30 parts by weight.

[0281] In another embodiment, the content of 2,6-TDI may be from about 1 part by weight to about 40 parts by weight relative to 100 parts by weight of the 2,4-TDI, for example, from about 1 part by weight to about 30 parts by weight, for example, from about 1 part by weight to about 20 parts by weight, for example, from about 1 part by weight to about 10 parts by weight.

[0282] In one embodiment, the second isocyanate compound comprises the aromatic diisocyanate and the alicyclic diisocyanate, wherein the content of the alicyclic diisocyanate may be from about 5 parts by weight to about 30 parts by weight relative to the total 100 parts by weight of the aromatic diisocyanate, for example, from about 10 parts by weight to about 25 parts by weight.

[0283] When the second urethane-based prepolymer satisfies the above-described compositional characteristics, the polishable variable layer ensures the physical / mechanical properties necessary to achieve the desired variability. Furthermore, forming additional structures such as grooves on the first surface of the polishable variable layer ensures improved processability. Additionally, the overall structure of the polishing layer stacked with the polishable constant layer further facilitates ensuring uniformity in the optimization of polishing performance while subdividing physical properties in the thickness direction.

[0284] The isocyanate group content (NCO%) of the composition used to form the polishable variable layer can be from about 5% by weight to about 11% by weight, for example, from about 5% by weight to about 10% by weight. In one embodiment, the isocyanate group content (NCO%) can be from about 5% by weight to about 8.5% by weight, and in another embodiment, the isocyanate group content (NCO%) can be from about 8.5% by weight to about 10% by weight. The "isocyanate group content" refers to the percentage of isocyanate groups (-NCO) that have not undergone urethane reaction and are present as free reactive groups in the total weight of the composition used to form the polishable variable layer. The NCO% of the composition used to form the polishable variable layer is defined as the value measured in the state after removing the second curing agent and the second foaming agent described later. The isocyanate group content (NCO%) of the composition can be designed by comprehensively adjusting the type and content of the monomers used to prepare the second urethane-based prepolymer, the process conditions such as temperature and pressure of the second urethane-based prepolymer preparation process, and the type of additives used in the preparation of the second urethane-based prepolymer. When the isocyanate group content meets the specified range, it is advantageous for the polishing variable layer 101 prepared by curing the composition to ensure appropriate physical / mechanical properties and to be applied in a stacked state with the polishing constant layer 102, thus enabling the polishing object to be endowed with excellent polishing performance through the first surface 11.

[0285] The composition used to prepare the polished variable layer may further include a second curing agent and a second foaming agent. The second curing agent and the second foaming agent may each contain the same components as the first curing agent and the first foaming agent, or they may contain different components.

[0286] In one embodiment, the second curing agent may comprise a compound containing a reactive group selected from the group consisting of amine (-NH2), alcohol (-OH), and combinations thereof. The "reactive group" refers to a terminal functional group that directly participates in the chemical reaction when the second curing agent reacts with a heterogeneous compound such as the second urethane-based prepolymer. In other words, the second curing agent may comprise, for example, a compound containing only an amine (-NH2) group as a reactive group in one molecule, or a compound containing only an alcohol (-OH) group as a reactive group in one molecule, or a compound containing both an amine (-NH2) group and an alcohol (-OH) group as reactive groups in one molecule.

[0287] For example, the second curing agent may comprise a compound selected from 4,4'-methylenebis(2-chloroaniline) (MOCA), diethyltoluenediamine (DETDA), diaminodiphenylmethane, dimethylthio-toluenediamine (DMTDA), and propanediol bis(p-aminobenzoate). One of the following groups: bisp-aminobenzoate, methylenebis-methylanthranilate, diaminodiphenylsulfone, m-xylylenediamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, bis(4-amino-3-chlorophenyl)methane, triethanolamine, tripropanolamine, triisopropanolamine, and combinations thereof.

[0288] In one implementation, the first curing agent may comprise a compound containing an alcohol group as a reactive group in one molecule, and the second curing agent may comprise a compound containing an amine group as a reactive group in one molecule. By using the first and second curing agents in this way, excellent interfacial physical properties of the polishing variable layer and the polishing constant layer can be ensured, and the overall physical properties of the polishing layer as a laminate can be more conducive to optimizing polishing performance.

[0289] In the overall composition used to form the polishable variable layer, the content of the second curing agent can be from about 15% to about 30% by weight, for example, from about 18% to about 27% by weight, for example, from about 19% to about 26% by weight, for example, from about 20% to about 26% by weight. By using the second curing agent in such a content, the polishable variable layer of the cured product containing the composition is more conducive to ensuring suitable mechanical and physical properties and appropriate variability for polishing.

[0290] The molar ratio (NCO:reactive group) of isocyanate groups (-NCO) in the composition used to form the polishable variable layer to the reactive groups of the second curing agent can be from about 1:0.80 to about 1:1.20, for example, from about 1:0.90 to about 1:1.10, for example, from about 1:0.90 to about 1:1.00, for example, greater than about 1:90 and less than about 1:1.00. For example, when the second curing agent contains a compound in which an amine group is included as a reactive group in one molecule, the molar ratio (NCO:NH2) of isocyanate groups (-NCO) in the composition to the amine group of the second curing agent can satisfy the range described above. Because the molar ratio satisfies the above range, a suitable crosslinking structure can be formed by the chemical reaction of the second urethane prepolymer and the second curing agent. As a result, the polishable variable layer ensures appropriate levels of physical / mechanical properties such as tensile strength and elongation, thereby facilitating the transfer of excellent polishing performance to the polished surface facing the first object to be polished.

[0291] The polished variable layer 101 may be a porous structure including a plurality of pores 15. At least a portion of the interior of the plurality of pores 15 located on the uppermost surface of the polished variable layer 101 may be exposed to the outside to impart a predetermined surface roughness to the first surface 11. Figure 2 The diagram schematically illustrates the structural changes of the first surface 11 in a polishing process of one implementation example. Specifically, Figure 2 This is a schematic diagram illustrating the structural changes of a portion of the plurality of pores 15 during polishing in one implementation example, wherein the interior of the portion of pores is exposed to the outside on the first surface 11. (Refer to...) Figure 2Since the plurality of pores 15 are dispersed throughout the variable polishing layer 101, a continuous surface roughness can be achieved even as the uppermost surface is gradually cut during the polishing process through the first surface 11. However, when the pores 15 are exposed to the first surface 11, the portion corresponding to the boundary between the first surface 11 and the pores 15 deforms under physical pressure as the polishing process continues under specified pressure conditions. This phenomenon affects the change in the surface roughness of the first surface 11. At this time, since the polishing layer comprises a stacked structure of the variable polishing layer 101 and the constant polishing layer 102, the surface physical properties calculated through the first surface 11 can be appropriately designed through the interaction of the thickness direction of each layer. As a result, it is more advantageous for the first surface 11 to maintain a surface condition suitable for polishing for a longer period of time.

[0292] In one implementation, the average size of the plurality of pores 15 included in the polishing variable layer 101 can be from about 5 μm to about 50 μm, for example, from about 5 μm to about 40 μm, for example, from about 10 μm to about 40 μm, for example, from about 10 μm to about 35 μm. Since the plurality of pores meets the above-mentioned size, it is advantageous for the first polishing variability index according to Formula 1 to meet the range, thus making it more advantageous to achieve the desired polishing performance itself and to achieve uniform performance throughout the overall lifetime of the polishing variable layer. The average size of the plurality of pores 15 is a two-dimensional value, which is based on the number mean of pore diameters measured on a projection map of the pore size taken using an imaging tool such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM), wherein the pores are those exposed on the outside of a surface based on the lifetime introduction time of the polishing variable layer 101.

[0293] The composition used to form the polishable variable layer may include a second foaming agent. The second foaming agent, as a component for forming the pore structure within the polishable variable layer 101, may include one selected from the group consisting of solid foaming agents, gaseous foaming agents, liquid foaming agents, and combinations thereof. In one implementation, the second foaming agent may include a solid foaming agent, a gaseous foaming agent, or a combination thereof.

[0294] The solid foaming agent may contain expandable particles. These expandable particles, which are particles that expand under heat or pressure, allow the final pore size to be determined by factors such as applied heat or pressure during the preparation of the polished variable layer 101. The expandable particles may include thermally expanded particles, unexpanded particles, or a combination thereof. "Temperaturely expanded" particles, defined as particles that expand pre-existing under heat, refer to particles whose size changes little or almost nothing due to the heat or pressure applied during the preparation of the polished variable layer. "Unexpanded" particles, defined as particles that do not expand pre-existing, refer to particles that expand under heat or pressure during the preparation of the polished layer and whose final size is determined.

[0295] The average particle size of the expandable particles can be from about 5 μm to about 200 μm, for example, from about 20 μm to about 50 μm, for example, from about 21 μm to about 50 μm, for example, from about 21 μm to about 40 μm. In the case of thermally expanded particles, the average particle size of the expandable particles can refer to the average particle size of the thermally expanded particles themselves; in the case of unexpanded particles, the average particle size of the expandable particles can refer to the average particle size after being expanded by applying heat or pressure.

[0296] The expandable particles may comprise: a resin outer skin; and an expansion-inducing component present inside the outer skin.

[0297] For example, the outer skin may comprise a thermoplastic resin, which may be one or more selected from the group consisting of vinyl chloride copolymers, acrylonitrile copolymers, methacrylonitrile copolymers, and acrylic copolymers.

[0298] The swelling-inducing component may include one selected from the group consisting of hydrocarbon compounds, chlorofluorocarbons, trialkylsilane compounds, and combinations thereof.

[0299] Specifically, the hydrocarbon compound may comprise one selected from the group consisting of ethane, ethylene, propane, propylene, n-butane, isobutene, butene, isobutene, n-pentane, isopentane, n-hexane, heptane, petroleum ether, and combinations thereof.

[0300] The fluorochloro compound may include one selected from the group consisting of trichlorofluoromethane (CCl3F), dichlorodifluoromethane (CCl2F2), chlorotrifluoromethane (CClF3), tetrafluoroethylene (CClF2-CClF2), and combinations thereof.

[0301] The trialkylsilane compound may comprise one selected from the group consisting of tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, trimethyl-n-propylsilane, and combinations thereof.

[0302] The second blowing agent comprises a solid blowing agent, which is based on 100 parts by weight of the second urethane-based prepolymer and can be used in amounts from about 0.5 parts by weight to about 10 parts by weight, for example, from about 1 part by weight to about 3 parts by weight, for example, from about 1.3 parts by weight to about 2.7 parts by weight, for example, from about 1.3 parts by weight to about 2.6 parts by weight.

[0303] The gaseous foaming agent may contain an inert gas. The gaseous foaming agent may be added during the reaction of the second urethane-based prepolymer with the second curing agent to serve as a pore-forming element.

[0304] There is no particular limitation on the type of inert gas, 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, it may include one selected from the group consisting of nitrogen (N2), argon (Ar), helium (He), and combinations thereof. Specifically, the inert gas may include nitrogen (N2) or argon (Ar).

[0305] In one implementation, the second foaming agent may be formed solely from a solid foaming agent.

[0306] In one implementation, the solid foaming agent may contain expandable particles, which may include thermally expandable particles. For example, the expandable particles may consist only of thermally expandable particles. When the expandable particles do not contain the unexpanded particles but consist only of thermally expandable particles, although the variability of the pore structure decreases, the predictability increases, thus facilitating the achievement of uniform pore characteristics in all regions of the polished variable layer.

[0307] In one implementation, the thermally expanded particles can be particles having an average particle size of about 5 μm to about 200 μm. The average particle size of the thermally 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 size is defined as the D50 of the thermally expanded particles.

[0308] In one implementation example, the density of the thermally expanded particles can be approximately 30 kg / m³. 3 Approximately 80 kg / m 3 For example, approximately 35 kg / m 3 Approximately 80 kg / m 3 For example, approximately 35 kg / m 3 Approximately 75 kg / m 3 For example, approximately 38 kg / m 3 Approximately 72 kg / m 3 For example, approximately 40 kg / m 3 Approximately 75 kg / m 3 For example, approximately 40 kg / m 3 Approximately 72 kg / m 3 .

[0309] In another embodiment, the second foaming agent may comprise a solid foaming agent and a gaseous foaming agent. The relevant aspects of the solid foaming agent are as described above.

[0310] The second foaming agent may comprise the solid foaming agent and the gaseous foaming agent, wherein the gaseous foaming agent may comprise nitrogen.

[0311] The gaseous blowing agent can be injected using a predetermined injection line during the 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 from about 0.8 L / min to about 2.0 L / min, for example, from about 0.8 L / min to about 1.8 L / min, for example, from about 0.8 L / min to about 1.7 L / min, for example, from about 1.0 L / min to about 2.0 L / min, for example, from about 1.0 L / min to about 1.8 L / min, for example, from about 1.0 L / min to about 1.7 L / min.

[0312] The composition used to prepare the polished variable layer may also contain other additives such as surfactants and reaction rate modifiers. The names "surfactant," "reaction rate modifier," etc., are arbitrarily chosen based on the primary function of the respective substance and do not imply that each substance only performs the function defined by its name.

[0313] There are no particular limitations on the surfactant, as long as it is a substance that prevents phenomena such as pore aggregation or overlap. For example, the surfactant may contain silicone polymers.

[0314] When the second composition contains the surfactant, based on 100 parts by weight of the second urethane-based prepolymer, the surfactant content can be from about 0.2 parts by weight to about 2 parts by weight, for example, from about 0.2 parts by weight to about 1.9 parts by weight, for example, from about 0.2 parts by weight to about 1.8 parts by weight, for example, from about 0.2 parts by weight to about 1.7 parts by weight, for example, from about 0.2 parts by weight to about 1.6 parts by weight, for example, from about 0.2 parts by weight to about 1.5 parts by weight, for example, from about 0.5 parts by weight to 1.5 parts by weight. When the surfactant is used in amounts within the aforementioned range, pores originating from the gas blowing agent can be stably formed and maintained within the cured mold.

[0315] The reaction rate regulator, as a regulator that promotes or delays the reaction, can be used as a reaction promoter, a reaction delayer, or both, depending on the intended use.

[0316] The reaction rate regulator may include a reaction promoter. For example, the reaction promoter may include one selected from the group consisting of tertiary amine compounds, organometallic compounds, and combinations thereof.

[0317] Specifically, the reaction rate regulator may comprise a subset selected from triethylenediamine, dimethylethanolamine, tetramethylbutanediamine, 2-methyl-triethylenediamine, dimethylcyclohexylamine, triethylamine, triisopropanolamine, 1,4-diazabicyclo(2,2,2)octane, bis(2-methylaminoethyl) ether, trimethylaminoethylethanolamine, N,N,N,N,N”-pentamethyldiethylenetriamine, dimethylaminoethylamine, dimethylaminopropylamine, benzyldimethylamine, N-ethylmorpholine, N,N-dimethyl... The reaction rate regulator may be selected from the group consisting of aminoethylmorpholine, N,N-dimethylcyclohexylamine, 2-methyl-2-azanorbornene, dibutyltin dilaurate, stannous octanoate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin maleate, dibutyltin bis(2-ethylhexanoate), and dibutyltin dithiol, and combinations thereof. In one embodiment, the reaction rate regulator may comprise one selected from the group consisting of benzyldimethylamine, N,N-dimethylcyclohexylamine, and triethylamine, and combinations thereof.

[0318] When the second composition contains the reaction rate modifier, based on 100 parts by weight of the second urethane-based prepolymer, it may contain 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 part by weight. When the reaction rate modifier is used within the above-mentioned content range, the curing reaction rate of the second composition can be adjusted, thereby facilitating the polishing variable layer having a desired pore size and hardness.

[0319] When the composition and content of the variable polishing layer and the constant polishing layer satisfy the above conditions, the polishing layer of the laminate can achieve precisely designed physical properties in the thickness direction. As a result, the mechanical and physical properties such as elasticity and rigidity of the polishing layer transmitted to the polished surface of the polished object through the first surface can be optimized in terms of polishing performance such as polishing rate, flatness, and defect prevention.

[0320] In another embodiment of the present invention, a method for fabricating a semiconductor device includes: providing a polishing pad including a polishing layer to a surface plate, the polishing layer having a polishing surface; configuring a polished surface of a polishing object to contact the polishing surface, and then rotating the polishing pad and the polishing object relative to each other under pressure to polish the polishing object; the polishing layer includes: a polishing variable layer including the polishing surface, and a polishing constant layer disposed on the back side of the polishing surface of the polishing variable layer; the ratio of the Shore D hardness of the polishing variable layer and the polishing constant layer is 0.50 to 1.50.

[0321] All matters concerning the polishing pad 110 are the same as described above. Specifically, the polishing layer 10, the first surface 11, the second surface 12, and the separable interface 13 of the polishing pad 110 are the same as described above regarding the polishing pad 110. When the polishing pad 110 is applied to the semiconductor device fabrication method, high-quality semiconductor devices can be produced under optimal physical properties achieved by the structure and composition characteristics of the polishing pad 110 as described above.

[0322] Specifically, the ratio of the Shore D hardness of two adjacent surfaces relative to the separable interface can be from about 0.50 to about 1.50, for example, from about 0.60 to about 1.50, for example, from about 0.70 to about 1.40, for example, from about 0.80 to about 1.20. As described above, through the subdivision design in the thickness direction of the polishing pad, the method for fabricating the semiconductor device using the polishing pad can ensure excellent polishing results in terms of polishing flatness and defect prevention.

[0323] In another embodiment of the present invention, a method for fabricating a semiconductor device is provided, comprising: providing a polishing pad including a polishing layer to a surface plate, the polishing layer including a first surface as a polishing surface and a second surface as a back surface of the first surface; and configuring the polished surface of a polishing object to contact the first surface, and then rotating the polishing pad and the polishing object relative to each other under pressure to polish the polishing object; the polishing layer including at least one separable interface between the first surface and the second surface; the polishing layer including: at least one polishable variable layer as a region from the first surface to the separable interface, and at least one polishable constant layer as a region from the separable interface to the second surface; the polishable constant layer including thermosetting polyurethane particles and a cured composition containing an adhesive (binder).

[0324] In the method for fabricating the semiconductor device, the description of the polishing pad and all subsequent structures should be understood as a comprehensive application of the specific description of the polishing pad as described above and its technical advantages in the following description of the method for fabricating the semiconductor device.

[0325] When the polishing pad 110 is applied to the method for fabricating the semiconductor device, semiconductor devices of excellent quality can be produced under the optimal physical properties achieved by the structure and composition characteristics of the polishing pad 110 as described above.

[0326] Specifically, the polishing pad 110 uses a polishing layer 10 with a stacked structure including the variable polishing layer 101 and the constant polishing layer 102. The constant polishing layer 102 uses a cured composition of thermosetting polyurethane particles and a binder. Therefore, the polishing pad 110 can be subdivided in the thickness direction. The method for fabricating the semiconductor device using the polishing pad 110 can ensure excellent polishing results in terms of polishing flatness, polishing rate and defect prevention.

[0327] All matters concerning the thermosetting polyurethane particles and the adhesive are the same as those stated above regarding the polishing pad 110.

[0328] Specifically, in one implementation, the average particle size of the thermosetting polyurethane particles can be from about 20 μm to about 3.0 mm, for example, from about 50 μm to about 2.0 mm, for example, from about 100 μm to about 2.0 mm. The “average particle size” is a numerical average of the diameters measured based on a cross-section of the particles, and can be obtained from a two-dimensional projection image of the particles. There are no particular limitations on the method for obtaining the projection image; it can be obtained using, for example, a scanning electron microscope (SEM) or a transmission electron microscope (TEM). By applying particles of this size, the support rigidity of the polishing invariant layer 102 can be improved, and it can help ensure the long-term durability of the polishing variable layer 101.

[0329] In one implementation, the thermosetting polyurethane particles may be particles derived from waste materials of a polishing pad containing thermosetting polyurethane. Specifically, the thermosetting polyurethane particles may be derived from the pulverized product of polishing pad waste containing thermosetting polyurethane. When the polishing pad uses particles derived from the waste materials of the polishing pad as a structure of the polishing invariant layer 102, the above-mentioned technical objectives can be achieved while also gaining the advantage of achieving environmental protection effects.

[0330] The adhesive comprises a first urethane-based prepolymer and a first curing agent. For example, the first urethane-based prepolymer may comprise a reaction product of a first isocyanate compound and a first polyol compound. Specific examples and implementations of the first urethane-based prepolymer, the first curing agent, the first isocyanate compound, and the first polyol compound, as well as their technical advantages, can be applied in the same way as the detailed description of the polishing pad 110.

[0331] Figure 4 This is a schematic diagram illustrating a method for fabricating the semiconductor device according to one implementation example. (Refer to...) Figure 4 The polishing pad 110 can be disposed on the surface plate 120. When the polishing pad 110 is disposed on the surface plate 120, the first surface 11 of the polishing layer 10 becomes the uppermost surface, and the second surface 12 can be disposed facing the surface plate 120.

[0332] In one implementation, the polishing pad 110 and the surface plate 120 can be attached via an adhesive layer medium. For example, the adhesive layer can be derived from pressure-sensitive adhesive (PSA), but is not limited thereto.

[0333] The method for fabricating the semiconductor device includes the following steps: after configuring the polished surface of the polishing object 130 to contact the first surface 11, the polishing pad 110 and the polishing object 130 are rotated relative to each other under pressure to polish the polishing object 130.

[0334] In one embodiment, the polishing object 130 may be a semiconductor substrate. For example, the polished surface of the semiconductor substrate may include a metal oxide film, a metal nitride film, or a metal film. In one embodiment, the polished surface may be a single film made of one of metal oxides, metal nitrides, and metals. In another embodiment, the polished surface may be a composite film including at least two or more of metal oxides, metal nitrides, and metals.

[0335] In the metal oxide film, the metal nitride film, and the metal film, the respective metal components may include one selected from the group consisting of silicon (Si), copper (Cu), tantalum (Ta), titanium (Ti), molybdenum (Mo), and combinations thereof.

[0336] In one embodiment, the surface to be polished of the polishing object 130 may be a single film made of silicon oxide. In another embodiment, the surface to be polished of the polishing object 130 may be a single film made of copper. In yet another embodiment, the surface to be polished of the polishing object 130 may be a composite film including a silicon oxide film. In yet another embodiment, the surface to be polished of the polishing object 130 may be a composite film including a copper film.

[0337] The load applied to the polished surface 130 by the polishing pad 11 can be appropriately designed according to the type and purpose of the polished surface; for example, it can be from about 0.01 psi to about 20 psi, or from about 0.1 psi to about 15 psi. As described above, the polishing pad 110 has a structural characteristic of being subdivided in the thickness direction. This structural characteristic allows for the provision of appropriate rigidity and elasticity to the polished surface under pressure conditions within the range described, meeting various purposes. As a result, when 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.

[0338] The polishing pad 110 and the polishing object 130 can rotate relative to each other with their respective polishing surfaces 11 and the surfaces to be polished in contact. At this time, the rotation direction of the polishing object 130 and the rotation direction of the polishing pad 110 can be the same or opposite. The polishing surfaces 11 and 130 can be in direct contact or indirectly contacted through components included in a flowable slurry. The rotation speeds of the polishing object 130 and the polishing pad 110 can be selected according to the purpose, ranging from about 10 rpm to about 500 rpm, for example, from about 30 rpm to about 200 rpm, but are not limited thereto. As described above, the polishing pad 110 can provide polishing performance suitable for various purposes through its structural characteristics of subdivision in the thickness direction. When the polishing object 130 and the polishing pad 110 rotate at rotation speeds within the range described above while in contact with each other, the actions of their centrifugal force and friction are related to the structural characteristics of the polishing pad 110, thus achieving excellent polishing results in terms of polishing flatness and defect prevention for the polished surface.

[0339] Reference Figure 1 The polishing layer 10 may include: at least one variable polishing layer 101, as the region from the polishing surface 11 to the separable interface 13; and at least one constant polishing layer 102, as the region from the separable interface 13 to the second surface 12. All matters concerning the variable polishing layer 101 and the constant polishing layer 102 are the same as those described above regarding the polishing pad 110 and its preparation method.

[0340] In the method for fabricating the semiconductor device, according to Formula 1, the first polishing variability index of the polishing variable layer 101 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 1.8 to 3.5, for example, it can be about 1.8 to 2.5.

[0341] The variable polishing layer 101 is a region in which the physical and / or chemical properties change during the polishing process of a semiconductor device fabrication method using the polishing pad 110, and has a predetermined lifetime in providing a target level of polishing performance. The lifetime initiation point of the variable polishing layer 101 refers to any point in time either in which the region itself is applied or before the polishing pad 110 is applied to the process after its fabrication. Furthermore, the lifetime end point of the variable polishing layer 101 refers to the point in time when the variable polishing layer 101 can no longer achieve the desired polishing performance, thus requiring replacement of the region itself or the entire polishing pad 110.

[0342] The first polishing variability index according to Equation 1, which takes the surface roughness Ri and Rf at the lifetime entry point and lifetime end point of the polishing variable layer 101, and the total thickness Ti and Tf of the polishing pad 110 as factors, is an indicator representing the variable performance of the polishing variable layer 101. By keeping the value of Equation 1 within the above range, that is, representing a variability of about 0.1 to about 11.0, the polishing variable layer 101 can have structural characteristics optimized for polishing efficiency as part of the polishing layer 10, while achieving a certain polishing performance throughout its lifetime. Therefore, it is more conducive to the mass production of semiconductor devices of the same quality.

[0343] The Ti can be, for example, 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.

[0344] The Ri can be, for example, 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.

[0345] In one implementation example, when Ti and Ri satisfy the above ranges respectively, and the first polishing variability index also satisfies the above ranges, it is more conducive to achieving polishing performance based on the structural characteristics of the polishing variable layer 101.

[0346] In one implementation, the polishing pad 110 may include at least one groove 14 on the polishing surface 11, having a depth d1 less than or equal to the total thickness D1 of the variable polishing layer 101. The groove 14 serves to appropriately achieve physical polishing characteristics by adjusting the flowability of the polishing fluid or slurry supplied to the polishing surface 11 during the polishing process using the polishing pad 110, or by adjusting the size of the area of ​​direct contact between the polishing surface 11 and the surface to be polished.

[0347] For example, the polishing pad 110 may include a plurality of grooves 14 on the polishing surface 11. In one implementation, the planar shape of the polishing pad 110 may actually be circular, and the plurality of grooves 14 may be concentric circular structures arranged at predetermined intervals from the center of the planar surface of the polishing pad 110 toward its ends. In another embodiment, the plurality of grooves 14 may be radial structures continuously formed from the center of the planar surface of the polishing pad 110 toward its ends. In yet another embodiment, the plurality of grooves 14 may simultaneously include concentric circular grooves and radial grooves.

[0348] In the polishing variable layer 101, which forms the region from the polished surface 11 to the separable interface 13, the polished surface 11 may include at least one trench 14. In this case, in the method of fabricating the semiconductor device, according to the following formula 2, the second polishing variability index of the polishing variable layer 101 may 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, for example, it may be about 0.6 to about 1.0.

[0349] According to Equation 2, the second polishing variability index of the polishing variable layer 101 can be from about 0.1 to about 3.5, for example, from about 0.1 to about 3.3, for example, from about 0.1 to about 3.0, for example, from about 0.1 to about 2.0, for example, from about 0.3 to about 1.8, for example, from about 0.5 to about 1.5, for example, from about 0.5 to about 1.2, for example, it can be from about 0.5 to 1.0.

[0350] The descriptions of the lifetime initiation and lifetime end times of the polishing variable layer 101 are the same as those given above regarding the first polishing variability index according to Equation 1. When the second polishing variability index of the polishing variable layer 101 satisfies the above-mentioned range, the polishing variable layer 101 can provide the most suitable structure in terms of the fluidity of the polishing liquid or polishing slurry, and the direct contact area provided to the polished surface can be ensured at an appropriate level, thus making it more conducive to ensuring the polishing rate within the target range.

[0351] For example, the Gi 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.

[0352] In one implementation example, when Ri and Gi satisfy the above ranges, and the second polishing variability index also satisfies the above ranges, it is more conducive to achieving polishing performance based on the structural characteristics of the polishing variable layer 101.

[0353] When the polished surface 11 includes at least one groove 14 having a depth less than or equal to the total thickness of the polished variable layer 101, in the polished variable layer 101, according to Formula 3, the depth variation rate (%) of the groove 14 can be from about 20% to about 80%, for example, from about 30% to 80%, for example, from about 40% to about 80%, for example, from about 45% to about 75%, for example, from about 50% to about 70%.

[0354] When the first surface 11 includes at least one groove 14 having a depth less than or equal to the total thickness of the polished variable layer 101, in the polished variable layer 101, according to Equation 3, the depth variation rate (%) of the groove 14 can be from about 20% to about 100%.

[0355] Reference Figure 1The depth d1 of the groove 14 can vary during the polishing process from the depth Gi at the lifetime initiation time point to the depth Gf at the lifetime end time point. Specifically, as the polishing surface 11 and the polished surface of the object being polished come into physical contact and are polished, the depth d1 of the groove 14 gradually becomes shallower through the cutting process of the polishing surface 11. At this time, the value of Equation 3, which takes the groove depth Gi at the lifetime initiation time point and the groove depth Gf at the lifetime end time point as elements, can satisfy the above range if the physical properties of the polishing variable layer 101, such as elongation, tensile strength, and hardness, are appropriately supported. Specifically, if the physical properties of the polishing variable layer 101 are not appropriately supported, as the groove depth d1 becomes shallower, the influence of changes in the fluidity of the polishing slurry on the polishing performance increases, thus posing a risk of a rapid decline in overall polishing performance. As the value of Equation 3 satisfies the above range, the polishing variable layer 101 according to an implementation example can represent the corresponding optimal physical properties. Based on this, even if the depth d1 of the trench becomes shallower, excellent polishing performance can be achieved in the overall polishing process according to the semiconductor device fabrication method by minimizing the impact on polishing performance.

[0356] When the polishing pad 110 includes at least one groove on the polishing surface 11, the width w1 of the groove 14 can be from about 0.2 mm to about 1.0 mm, for example, from about 0.3 mm to about 0.8 mm, for example, from about 0.4 mm to about 0.7 mm. When the width of the groove 14 meets the range, the size of the contact area between the polished surface of the polished object 130 and the polishing surface 11 can be appropriately ensured, and the fluidity of the polishing liquid or polishing slurry applied to the polishing surface 11 is ensured to be at an appropriate level, thereby achieving excellent final polishing performance.

[0357] When the polishing pad 110 includes a plurality of trenches 14 on the polishing surface 11, the pitch p1 of the trenches 14, defined as the interval between two adjacent trenches 14, is also appropriately designed with the same technical concept as the width w1 of the trenches 14, thereby contributing to achieving the polishing performance required for the fabrication method of the semiconductor device. For example, the pitch p1 of the trenches 14 can be from about 1.5 mm to about 5.0 mm, for example, from about 1.5 mm to about 4.0 mm, for example, from about 1.5 mm to about 3.0 mm.

[0358] Reference Figure 4 In one embodiment, the method for fabricating the semiconductor device may further include the step of supplying polishing slurry 150 to the polishing surface 11 of the polishing pad 110. For example, the polishing slurry 150 may be supplied to the polishing surface 11 via a supply nozzle 140.

[0359] The flow rate of the polishing slurry 150 sprayed through the supply nozzle 140 can be from about 10 ml / min to about 1000 ml / min, for example, from about 10 ml / min to about 800 ml / min, for example, from about 50 ml / min to about 500 ml / min, but is not limited thereto.

[0360] The polishing slurry 150 may contain silica slurry or cerium dioxide slurry, but is not limited to these.

[0361] Reference Figure 4 The polishing object 130 can continue to apply pressure and polish the polishing surface 11 under a specified load while mounted on the polishing head 160. When the polishing object 130 is mounted on the polishing head 160, its polished surface can be mounted facing the polishing surface 11. The load on the polished surface of the polishing object 130 applying pressure to the polishing surface 11 can be appropriately designed according to the type and purpose of the polished surface, for example, it can be from about 0.01 psi to about 20 psi, for example, from about 0.1 psi to about 15 psi, for example, from about 1 psi to about 12 psi, for example, from about 3 psi to about 6 psi.

[0362] In one implementation, in order to keep the polishing surface 11 of the polishing pad 110 in a suitable polishing state, the method for fabricating the semiconductor device may further include the step of processing the polishing surface 11 by means of an adjuster 170 while polishing the polishing object 130.

[0363] The regulator 170 can perform the function of roughening the polished surface 11 while rotating at a specified rotational rate. The rotational rate of the regulator 170 can be, for example, from about 50 rpm to about 150 rpm, or, for example, from about 80 rpm to about 120 rpm. Through the surface treatment by the rotation of the regulator 170, the polished surface 11 can maintain an optimal surface condition throughout the polishing process, and the polishing life can be extended.

[0364] The pressure applied to the polished surface 11 of the regulator 170 can be, for example, from about 1 lbf to about 12 lbf, or, for example, from about 3 lbf to about 9 lbf. By pressurizing the regulator 170 and performing the surface treatment under these conditions, the polished surface 11 can maintain optimal surface condition throughout the overall polishing process and can extend the polishing life.

[0365] Examples and Comparative Examples

[0366] Example 1

[0367] An aromatic diisocyanate comprising 25 parts by weight of 2,6-toluene diisocyanate (2,6-TDI) is prepared relative to 100 parts by weight of the aromatic diisocyanate, and 11 parts by weight of 4,4'-dicyclohexylmethane diisocyanate (H) is mixed relative to the total 100 parts by weight of the aromatic diisocyanate. 12 The isocyanate component was prepared by mixing MDI. 130 parts by weight of polytetramethylene ether glycol (PTMG) with a weight-average molecular weight (Mw) of 1000 g / mol were prepared relative to 100 parts by weight of the isocyanate component, and 14 parts by weight of diethylene glycol (DEG) with a weight-average molecular weight (Mw) of 106 g / mol were mixed relative to 100 parts by weight of the isocyanate component to prepare the polyol component. A pre-composition containing urethane-based prepolymers was prepared by reacting the mixture of the isocyanate and polyol components in a four-necked flask at 80°C. The isocyanate group (NCO group) content in the pre-composition was adjusted to 9% by weight. 4,4'-methylenebis(2-chloroaniline) (MOCA) was mixed into the pre-composition as a curing agent, such that the molar ratio of the NH2 groups of the MOCA to the NCO groups in the pre-composition was 0.96. Additionally, 1.0 part by weight of a solid foaming agent (Akzonobel) as expanding particles and 1.0 part by weight of a silicone surfactant (OFX-193) were mixed into the pre-composition. The pre-composition was injected into a mold with a width of 1000 mm, a length of 1000 mm, and a height of 3 mm, preheated to 90°C, at an injection rate of 10 kg / min. Simultaneously, nitrogen (N2) gas was injected as a gaseous foaming agent at an injection rate of 1.0 L / min for the same duration as the injection of the pre-composition. The pre-composition was then subjected to a post-curing reaction at 110°C to prepare a sheet. The sheet was then line-turned to create concentric circular grooves with a surface width w1 of 0.5 mm, a pitch p1 of 3.0 mm, and a depth d1 of 0.85 mm to prepare a polished variable layer with a thickness of 1.0 mm.

[0368] On the other hand, an aromatic isocyanate compound containing 4,4'-diphenylmethanediisocyanate (MDI) was prepared. Relative to 100 parts by weight of the MDI, 18 parts by weight of 1,4-butanediol and 71 parts by weight of polytetramethylene ether glycol (PTMG 650) were mixed and placed into a cake mold with a width of 1000 mm, a length of 1000 mm, a height of 3 mm, and preheated to 80°C. The mixture was then cured for 120 minutes. After curing at room temperature, it was aged at 110°C for 12 hours and then cut into 1.0 mm thick pieces to prepare a polishing invariant layer.

[0369] On the other hand, a buffer layer with a thickness of 1.1 mm is prepared, having a structure in which a polyurethane resin is impregnated in a polyester resin nonwoven fabric.

[0370] Double-sided adhesive tape is attached to the back side of the grooved surface of the variable polishing layer, both sides of the constant polishing layer, and one side of the buffer layer. The variable polishing layer, the constant polishing layer, and the buffer layer are then stacked in sequence, with the tape attachment surfaces in contact with each other before lamination, to prepare a polishing pad with a total thickness of 3.2 (±0.5 mm).

[0371] Example 2

[0372] An aromatic isocyanate compound containing 4,4'-diphenylmethanediisocyanate (MDI) was prepared. Relative to 100 parts by weight of the MDI, 14 parts by weight of 1,4-butanediol and 100 parts by weight of polytetramethylene ether glycol (PTMG 650) were mixed and placed into a cake mold with a width of 1000 mm, a length of 1000 mm, and a height of 3 mm, and preheated to 80°C. The mixture was then cured for 120 minutes, followed by curing at room temperature. After curing at 110°C, it was further cured for 12 hours. The resulting product was then cut into 1.0 mm thick pieces to prepare a polishing-resistant layer.

[0373] On the other hand, a buffer layer with a thickness of 1.1 mm is prepared, having a structure in which a polyurethane resin is impregnated in a polyester resin nonwoven fabric.

[0374] Double-sided adhesive tape is attached to the back side of the grooved surface of the variable polishing layer, both sides of the constant polishing layer, and one side of the buffer layer. The variable polishing layer, the constant polishing layer, and the buffer layer are then stacked in sequence, with the tape attachment surfaces in contact with each other before lamination, to prepare a polishing pad with a total thickness of 3.2 (±0.5 mm).

[0375] Comparative Example 1

[0376] In Example 1, the polishing constant layer is not included. The polishing variable layer is prepared with a thickness of 2.0 mm. Double-sided tape is attached to the back side of the grooved surface of the polishing variable layer and one side of the buffer layer. After each tape attachment surface is in contact with each other, they are laminated to prepare a polishing pad with a total thickness of 3.1 (±0.5 mm). Otherwise, the polishing pad is prepared in the same way as in Example 1.

[0377] Comparative Example 2

[0378] In Example 1, the polishing constant layer is not included. Double-sided tape is attached to the back side of the grooved surface of the polishing variable layer and one side of the buffer layer. The tapes are then laminated after contact between their respective attachment surfaces to prepare a polishing pad with a total thickness of 2.1 (±0.5 mm). Otherwise, the polishing pad is prepared using the same method as in Example 1.

[0379] Comparative Example 3

[0380] An aromatic isocyanate compound containing 4,4'-diphenylmethanediisocyanate (MDI) was prepared. 11 parts by weight of 1,4-butanediol and 120 parts by weight of polytetramethylene ether glycol (PTMG 650) were mixed with 100 parts by weight of the MDI. The mixture was then placed into a cake mold with a width of 1000 mm, a length of 1000 mm, and a height of 3 mm, and preheated to 80°C. After curing at room temperature, the mixture was aged at 110°C for 12 hours. It was then cut into 1.0 mm thick pieces to prepare a polishing-resistant layer. Otherwise, a polishing pad was prepared using the same method as in Example 1.

[0381] Evaluate

[0382] Experimental Example 1: Evaluation of Hardness Properties

[0383] The Shore D hardness of each of the polishing variable layer, polishing constant layer, buffer layer, and laminates composed of at least one combination thereof in the embodiments and comparative examples was measured. Specifically, samples were prepared by cutting them into 5cm × 5cm pieces, and each sample was stored at 25°C for 12 hours before being measured using a Bareiss (HPEIII) hardness tester. Furthermore, based on the respective hardness measurements, the ratio H2 / H1 of the hardness H1 of the polishing variable layer to the hardness H2 of the polishing constant layer, the ratio Hc / Hp of the hardness Hp of the polishing layer to the hardness Hc of the buffer layer, and the ratio Hp / Ht of the hardness Hp of the polishing layer to the overall hardness Ht of the polishing pad were calculated. The results are shown in Table 1.

[0384] Experiment Example 2: Compression Characteristics Evaluation

[0385] For each 25mm × 25mm polishing pad sample of the embodiments and comparative examples, the initial thickness D1 under no-load conditions was measured, and the thickness D2 after deformation was measured under the pressure condition of applying an 800g weight to the sample for 3 minutes at room temperature. The compression ratio (%) was then derived using the formula D1 - D2 / D1 × 100.

[0386] Experimental Example 3: Evaluation of Polishing Variables

[0387] For each of the embodiments and comparative examples, based on the centerline average roughness Ra, the surface roughness Ri of the first surface of the polishing variable layer before it is applied to the polishing process after the preparation of each polishing pad was measured, and the total thickness Ti of each polishing pad and the depth Gi of the trenches on each first surface were measured.

[0388] Then, lifetime prediction was performed by simulating polishing evaluations on each polishing pad. The pads were aged using a dummy wafer with a silicon oxide film and a 4-inch regulator for calcined cerium oxide slurry (KC Tech's ACS-350), and time-lapse wafers were used to measure changes in polishing rate. Polishing conditions were performed at 4.0 psi pressure and a slurry inflow rate of 200 mm / L to evaluate the polished surface of the polishing head.

[0389] For each polishing pad, the point at which the polishing rate changes by 20% compared to the initial polishing rate was taken as the end of the polishing pad's lifespan. Based on the centerline average roughness Ra, the surface roughness Rf of the first surface of the polishing variable layer of each dried polishing pad was measured, as were the total thickness Tf of each polishing pad and the groove depth Gf of each first surface. The results are shown in Table 1.

[0390] Experiment Example 4: Polishing Performance Evaluation

[0391] For each polishing pad in the embodiments and comparative examples, polishing was performed using the same method as in Experimental Example 3, and the polishing performance was evaluated as described below. The results are shown in Table 1.

[0392] (1) Average polishing rate

[0393] Polishing was performed using the same method as in Experimental Example 3. After 1 minute of polishing, the change in film thickness of the dried silicon wafer before and after polishing was measured using an optical interferometer (SI-F80R, Kyence). The polishing rate was then calculated using the following formula. The polishing rate was measured a total of 5 times, and the average value was taken as the average polishing rate.

[0394]

[0395] (2) Defects

[0396] Polishing was performed using the same method as in Experimental Example 3. After polishing for 1 minute, the number of defects such as scratches was counted by visually observing the polished surface of the object. Specifically, after polishing, the silicon wafer was moved to a cleaner and washed for 10 seconds each with 1% hydrogen fluoride (HF) and purified water (DIW), and 1% nitric acid (H2NO3) and purified water (DIW). Then, the silicon wafer was moved to a rotary dryer, washed with purified water (DIW), and dried with nitrogen (N2) for 15 seconds. The changes in defects before and after polishing were then observed visually using a defect detection device (Tenkor, XP+).

[0397] (3) Polishing flatness

[0398] Polishing was performed using the same method as in Experimental Example 3, and after 1 minute of polishing, the in-plane film thickness of 98 wafers was measured, and the formula (standard deviation of polished thickness) was used. Average polishing thickness The polishing flatness (WIWNU: Within Wafer Non Uniformity, %) is derived by multiplying by 100.

[0399] Table 1

[0400]

[0401] Referring to Table 1, the polishing pads of Examples 1 and 2 employ a laminated structure of a variable polishing layer and a constant polishing layer made of different materials in the polishing layer. The hardness ratio of the two layers is designed to be in the range of approximately 0.50 to approximately 1.50. This demonstrates that, compared to Comparative Examples 1 to 3, they achieve the same or better polishing performance in terms of polishing rate, defects, and polishing flatness. Furthermore, by using easily recyclable thermoplastic resin as the material for the constant polishing layer, the polishing pads of Examples 1 and 2 also demonstrate improved productivity and economic efficiency in addition to polishing functionality.

[0402] The following provides specific embodiments of the present invention. However, the following embodiments are merely illustrative or descriptive of the invention, and the scope of the invention is not limited thereto; rather, it is defined by the claims.

[0403] Example 3

[0404] An aromatic diisocyanate comprising 25 parts by weight of 2,6-toluene diisocyanate (2,6-TDI) is prepared relative to 100 parts by weight of the aromatic diisocyanate, and 11 parts by weight of 4,4'-dicyclohexylmethane diisocyanate (H) is mixed relative to the total 100 parts by weight of the aromatic diisocyanate. 12 The isocyanate component was prepared by mixing MDI. 130 parts by weight of polytetramethylene ether glycol (PTMG) with a weight-average molecular weight (Mw) of 1000 g / mol were prepared relative to 100 parts by weight of the isocyanate component, and 14 parts by weight of diethylene glycol (DEG) with a weight-average molecular weight (Mw) of 106 g / mol were mixed relative to 100 parts by weight of the isocyanate component to prepare the polyol component. A pre-composition containing urethane-based prepolymers was prepared by reacting the mixture of the isocyanate and polyol components in a four-necked flask at 80°C. The isocyanate group (NCO group) content in the pre-composition was adjusted to 9% by weight. 4,4'-methylenebis(2-chloroaniline) (MOCA) was mixed into the pre-composition as a curing agent, such that the molar ratio of the NH2 groups of the MOCA to the NCO groups in the pre-composition was 0.96. Additionally, 1.0 part by weight of a solid foaming agent (Akzonobel) as expanding particles and 1.0 part by weight of a silicone surfactant (OFX-193) were mixed into the pre-composition. The pre-composition was injected into a mold with a width of 1000 mm, a length of 1000 mm, and a height of 3 mm, preheated to 90°C, at an injection rate of 10 kg / min. Simultaneously, nitrogen (N2) gas was injected as a gaseous foaming agent at an injection rate of 1.0 L / min for the same duration as the injection of the pre-composition. The pre-composition was then subjected to a post-curing reaction at 110°C to prepare a sheet. The sheet was then line-turned to create concentric circular grooves with a surface width w1 of 0.5 mm, a pitch p1 of 3.0 mm, and a depth d1 of 0.85 mm to prepare a polished variable layer with a thickness of 1.0 mm.

[0405] Byproducts generated during the processing of the grooves and thickness of the polished variable layer were pulverized using a grinding mill to achieve an average particle size of 1–2 mm (approximately 1.5 mm). Next, a pre-composition containing the same urethane-based prepolymer as the polished variable layer was prepared. A curing agent (MCNS Corporation, LA-750, OH-V 750) having alcohol groups as reactive groups was mixed into the pre-composition such that the molar ratio of the OH groups of the curing agent to the NCO groups in the pre-composition was 1.0, to prepare an adhesive composition. The thermosetting polyurethane particles were mixed together with each other in such a manner that approximately 100 parts by weight of the adhesive composition were contained, and then injected into a circular mold with an opening at the top and a diameter of 33 inches. A cured product was then obtained by curing at 110°C for 10 hours. A polished variable layer with a thickness of 1.0 mm was prepared by slicing the cured product.

[0406] On the other hand, a buffer layer with a thickness of 1.1 mm is prepared, having a structure in which a polyurethane resin is impregnated in a polyester resin nonwoven fabric.

[0407] Double-sided adhesive tape is attached to the back side of the grooved surface of the variable polishing layer, both sides of the constant polishing layer, and one side of the buffer layer. The variable polishing layer, the constant polishing layer, and the buffer layer are then stacked in sequence, with the tape attachment surfaces in contact with each other before lamination, to prepare a polishing pad with a total thickness of 3.2 (±0.5 mm).

[0408] Example 4

[0409] Compared to the preparation of the polishing-invariant layer in Example 3, the polishing pad was prepared by mixing the thermosetting polyurethane particles in a manner that yields approximately 900 parts by weight relative to 100 parts by weight of the adhesive composition.

[0410] Example 5

[0411] Compared to the preparation of the polishing-invariant layer in Example 3, the polishing pad was prepared by mixing the thermosetting polyurethane particles in a manner that resulted in approximately 11 parts by weight of each other relative to 100 parts by weight of the adhesive composition.

[0412] Comparative Example 4

[0413] In Example 3, the polishing constant layer is not included. The polishing variable layer is prepared with a thickness of 2.0 mm. After double-sided tape is attached to the back side of the grooved surface of the polishing variable layer and one side of the buffer layer, the tape is laminated after each tape attachment surface contacts each other to prepare a polishing pad with a total thickness of 3.1 (±0.5 mm). Otherwise, the polishing pad is prepared in the same way as in Example 1.

[0414] Evaluate

[0415] Experimental Example 5: Polishing Pad Hardness Evaluation

[0416] For each polishing pad in the embodiments and comparative examples, the Shore D hardness of the first surface, which serves as the polishing surface, was measured. Specifically, samples were prepared by cutting them into pieces with a width and length of 5 cm × 3 cm. After each sample was stored at 25°C for 12 hours, the Shore D hardness was measured using a Shore D hardness tester. The results are shown in Table 2 below.

[0417] Experiment Example 6: Evaluation of Polishing Pad Compression Ratio

[0418] For each polishing pad in the embodiments and comparative examples, the initial thickness D1 under no-load conditions was measured, and the thickness D2 after being pressurized under pressure conditions of 2400g of cylindrical weight with a cross-sectional area of ​​25mm and a diameter of 1 minute was measured. The compression ratio (%) was then derived by using the formula D1-D2 / D1×100.

[0419] Experiment 7: Evaluation of Polishing Variables

[0420] For each of the embodiments and comparative examples, based on the centerline average roughness Ra, the surface roughness Ri of the first surface of the polishing variable layer after the preparation of each polishing pad and before its application to the polishing process was measured, and the total thickness Ti of each polishing pad and the depth Gi of the trenches on each first surface were measured.

[0421] Then, for each polishing pad, silicon oxide (SiO2) was deposited on a 300 mm diameter silicon wafer using a chemical vapor deposition (CVD) process. The polishing pads were attached to a CMP apparatus, with the surface of the silicon oxide layer on the silicon wafer facing the polishing pads. While calcined cerium oxide slurry was fed onto the polishing pads at a rate of 250 mL / min, the silicon wafer was pressed onto the polishing surface under a load of 3.0 psi, and the silicon oxide film was polished by setting the rotational speeds of both the polishing pads and the silicon wafer to 100 rpm. Polishing continued until the polishing rate changed by 20% compared to the initial polishing rate. The silicon wafer was then removed from the carrier, mounted in a spin dryer, washed with distilled water, and dried with nitrogen for 15 seconds.

[0422] For each polishing pad, the point at which the polishing rate changes by 20% compared to the initial polishing rate is taken as the end of the polishing pad's lifespan. Based on the centerline average roughness Ra, the surface roughness Rf of the first surface of the polishing variable layer of each dried polishing pad was measured, and the total thickness Tf of each polishing pad and the depth Gf of the trenches on each first surface were measured.

[0423] Then, the first polishing variability index and the second polishing variability index are derived by using Equations 1 and 2, and the results are shown in Table 2 below.

[0424] Experiment Example 8: Polishing Performance Evaluation

[0425] For each polishing pad in the embodiments and comparative examples, polishing was performed using the same method as in Experimental Example 3, and the polishing performance was evaluated as described below. The results are shown in Table 2.

[0426] (4) Average polishing rate

[0427] Polishing was performed using the same method as in Experimental Example 6. After 1 minute of polishing, the change in film thickness of the dried silicon wafer before and after polishing was measured using an optical interferometric thickness gauge (F54, Filmetrics). The polishing rate was then calculated using the following formula. The polishing rate was measured a total of 5 times, and the average value was taken as the average polishing rate.

[0428]

[0429] (5) Defects

[0430] Polishing was performed using the same method as in Experimental Example 6. After polishing for 1 minute, the number of defects such as scratches was counted by visually observing the polished surface of the object. Specifically, after polishing, the silicon wafer was moved to a cleaner and washed for 10 seconds each with 1% hydrogen fluoride (HF) and purified water (DIW), and 1% nitric acid (H2NO3) and purified water (DIW). Then, the silicon wafer was moved to a rotary dryer, washed with purified water (DIW), and dried with nitrogen (N2) for 15 seconds. The changes in defects before and after polishing were then observed visually using a defect detection device (Tenkor, XP+).

[0431] (6) Polishing flatness

[0432] Polishing was performed using the same method as in Experimental Example 6, and after 1 minute of polishing, the in-plane film thickness of 49 wafers was measured, and the formula (standard deviation of polished thickness) was used. Average polishing thickness The polishing flatness (WIWNU: Within Wafer Non Uniformity, %) is derived by multiplying by 100.

[0433] Table 2

[0434]

[0435]

[0436] Referring to Table 2, the polishing pads of Examples 3 to 5 include a variable polishing layer and a constant polishing layer. Crushed particles, along with a predetermined binder, are applied to a recycled layer as the constant polishing layer. The crushed particles are pulverized using a grinding mill to break down byproducts generated during the processing of the grooves and thickness of the variable polishing layer into an average particle size of 1–2 mm (approximately 1.5 mm). Comparative Example 4 is a polishing pad without this recycled layer. Even though the polishing pads of Examples 3 to 5 include a recycled structure, they achieve the same level of polishing performance as Comparative Example 4. This confirms that in addition to the original polishing function, improvements can also be achieved in terms of process productivity and economy.

[0437] The preferred embodiments of the present invention have been described in detail above. However, the scope of the present invention is not limited thereto. Various modifications and improvements made by those skilled in the art based on the basic concepts of the present invention as defined in the appended scope of the claims also fall within the scope of the present invention.

Claims

1. A polishing pad, wherein, Including the polished layer, The polishing layer includes: a variable polishing layer having a polishing surface, and a constant polishing layer disposed on the back side of the polishing surface of the variable polishing layer. The interface between the variable polishing layer and the constant polishing layer is a separable interface. The ratio of the Shore D hardness of the variable polishing layer to the Shore D hardness of the constant polishing layer is 0.50 to 1.

50. The variable polishing layer accounts for 30% to 60% of the total volume of the polishing layer. According to Equation 1 below, the first polishing variability index of the polishing variable layer is 0.1 to 11.0; Formula 1 In Equation 1, Ri is the surface roughness Ra of the polished surface at the lifetime introduction time point of the polishing variable layer. Rf is the surface roughness Ra of the polished surface at the end of the lifetime of the variable polishing layer. Ti represents the total thickness of the polishing pad at the lifetime introduction time of the variable polishing layer. Tf is the total thickness of the polishing pad at the end of the lifetime of the variable polishing layer.

2. The polishing pad according to claim 1, wherein, The polishing variable layer includes at least one trench on the polished surface, having a depth less than or equal to the total thickness of the polishing variable layer. According to Equation 2 below, the second polishing variability index of the polishing variable layer is 0.1 to 3.5; Formula 2 In Equation 2, Ri is the surface roughness Ra of the polished surface at the lifetime introduction time point of the polishing variable layer. Rf is the surface roughness Ra of the polished surface at the end of the lifetime of the variable polishing layer. Gi is the depth of the trench at the lifetime introduction time point of the polishing variable layer. Gf is the depth of the trench at the end of the lifetime of the polished variable layer.

3. The polishing pad according to claim 1, wherein, The polishing variable layer includes at least one trench on the polished surface, having a depth less than or equal to the total thickness of the polishing variable layer. According to the following formula 3, the depth variation rate (%) of the trench is 20% to 100%; Formula 3 In Equation 3, Gi is the trench depth at the lifetime introduction time point of the polishing variable layer. Gf is the trench depth at the end of the lifetime of the polished variable layer.

4. The polishing pad according to claim 1, wherein, The Shore D hardness of the total laminate is 45 to 70.

5. The polishing pad according to claim 1, wherein, The polishing variable layer comprises a thermosetting resin. The polishing-resistant layer comprises a thermoplastic resin.

6. The polishing pad according to claim 1, wherein, The polishing-resistant layer comprises a cured composition comprising thermosetting polyurethane particles and an adhesive.

7. A method for fabricating a semiconductor device, in, include: The step of providing a polishing pad, including a polishing layer, to a surface plate, wherein the polishing layer has a polished surface, and The step of polishing an object by configuring the surface to be polished to contact the polishing surface, and then rotating the polishing pad and the object to be polished relative to each other under pressure. The polishing layer includes: a variable polishing layer including the polishing surface, and a constant polishing layer disposed on the back side of the polishing surface of the variable polishing layer; The interface between the variable polishing layer and the constant polishing layer is a separable interface. The ratio of the Shore D hardness of the variable polishing layer to the Shore D hardness of the constant polishing layer is 0.50 to 1.

50. The variable polishing layer accounts for 30% to 60% of the total volume of the polishing layer. According to Equation 1 below, the first polishing variability index of the polishing variable layer is 0.1 to 11.0; Formula 1 In Equation 1, Ri is the surface roughness Ra of the polished surface at the lifetime introduction time point of the polishing variable layer. Rf is the surface roughness Ra of the polished surface at the end of the lifetime of the variable polishing layer. Ti represents the total thickness of the polishing pad at the lifetime introduction time of the variable polishing layer. Tf is the total thickness of the polishing pad at the end of the lifetime of the variable polishing layer.

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