Regenerated polishing pad and preparation method thereof

Abstract

In accordance with an embodiment of the present invention, there is provided a regenerated polishing pad and a method of making a regenerated polishing pad. A recycled polishing pad including a buffer layer, an adhesive layer, and a recycled polishing layer having a plurality of grooves on one side, and a compression ratio of the recycled polishing layer calculated by a specific equation being controlled within a predetermined range; accordingly, it is possible to reuse the polishing layer while maintaining excellent polishing rate and polishing uniformity.

Description

Technical Field

[0001] This invention relates to a regenerated polishing pad, and to a method for preparing the same. Background Technology

[0002] Chemical mechanical polishing (CMP) processes can be performed in various technical fields for a variety of purposes. For example, CMP processes can be used to planarize the surfaces of materials and substrates used in semiconductor devices, electronic components, optical components, etc., remove aggregates, resolve lattice damage, and remove surface defects and contaminants.

[0003] In the CMP process, polishing pads are used to polish the surface of the object to be polished. Because the polishing pad interacts directly with the surface of the object being polished, it can affect the quality of the polished object. For example, the polishing characteristics of the CMP process can vary significantly depending on the composition and physical properties of the polishing pad.

[0004] With the emergence of environmental issues such as climate change in recent years, public opinion holds that companies should assume social responsibility through ESG management, such as carbon neutrality, to build a sustainable society. Polishing pads used in CMP processes are consumables, discarded after use and cannot be reused, which may cause environmental pollution. Therefore, efforts are being made to regenerate polishing pads after use.

[0005] Meanwhile, as the CMP process proceeds, the polishing pad's padding layer may wear down or thin. Conventionally, existing research on polishing pad recycling methods involves adding or supplementing new padding layers onto the polishing pad used to achieve the desired CMP performance. However, in this case, the process can become more complex and expensive because additional new padding layers are required for polishing pad reuse. Furthermore, other environmental problems may arise during the production of such new padding layers.

[0006] Therefore, there is a need to develop a technology that can improve the recyclability of polishing pads while giving them excellent physical properties that meet the requirements of CMP processes.

[0007] [Existing Technical Documents]

[0008] [Patent Literature]

[0009] (Patent Document 1) Korean Patent No. 10-0418648. Summary of the Invention

[0010] Technical issues

[0011] The technical problem to be solved by the present invention is to provide a regenerated polishing pad that, by comprising a reusable polishing layer with a predetermined compression ratio, can achieve the desired polishing rate and polishing uniformity, and has excellent CMP performance.

[0012] Furthermore, the present invention also provides a method for preparing a recycled polishing pad by using a reusable polishing layer having a predetermined compression ratio of the polishing pad.

[0013] Solution

[0014] A polishing pad according to one embodiment of the present invention includes a buffer layer; an adhesive layer formed on the buffer layer; and a reusable polishing layer attached to the adhesive layer and having a groove on one side, wherein the compression ratio of the reusable polishing layer, calculated by the following Equation 1, is 0.9% or greater.

[0015] Equation 1

[0016] The compression ratio (%) of the polished layer is then utilized =

[0017] In Equation 1, T1 is the thickness (mm) of the reused polished layer when it is pressed with a load of 85g for 30 seconds, and T2 is the thickness (mm) of the reused polished layer when it is further pressed with a load of 885g for 3 minutes after measuring T1.

[0018] Another embodiment of the present invention provides a method for preparing a recycled polishing pad, which involves recovering the polishing layer from a polishing pad used in a CMP process, planarizing one side of the polishing layer, forming a groove on the planarized side of the polishing layer to prepare a reusable polishing layer, and using an adhesive to attach a buffer layer to the other side of the reusable polishing layer. The compression ratio of the reusable polishing layer calculated using Equation 1 above can be 0.9% or higher.

[0019] Beneficial effects of the present invention

[0020] According to one embodiment of the invention, since the recycled polishing pad includes a reused polishing layer with a specific range of compression ratios, it can provide enhanced polishing rate and polishing uniformity.

[0021] Furthermore, since the compression ratio of the reused polishing layer is within the aforementioned range and includes grooves of a predetermined depth, the physical properties and polishing characteristics of the reused polishing pad can be maintained even better, and it is suitable for use in polishing processes.

[0022] According to another embodiment of the invention, since the polishing layer with a specific range of compression ratios is recycled from the polishing pads discarded after the polishing process to prepare reusable polishing pads, no additional replenishment pads are required, thereby simplifying the recycling process and reducing process costs. Attached Figure Description

[0024] Figure 1 This is a schematic cross-sectional view of a regenerated polishing pad according to an embodiment of the present invention.

[0025] Figures 2a to 2e These are schematic cross-sectional views of a portion of the polishing pad during each step of a method for preparing a regenerated polishing pad according to one embodiment.

[0026] Figures 3a to 3c The graphs show the polishing rates of the center, middle, and edge regions measured in Test Example 1.

[0027] Figures 4a to 4c The graphs show the distribution of polishing rate as a function of distance from the center, as measured in Test Example 1.

[0028] Figures 5a to 5c The graphs show the polishing rates of the central region, the middle region, and the edge region as measured in Test Example 3.

[0029] Figure 6a and Figure 6b The graphs show the polishing rates of the center, middle, and edge regions measured in Test Example 4.

[0030] Figure 7a and Figure 7b The graphs show the distribution of polishing rate as a function of distance from the center, as measured in test example 4.

[0031] Figure 8a and Figure 8b These are SEM images, magnified 5 times, of the cross-section of certain areas of the polishing pad in Example 1.

[0032] Figure 9a and Figure 9b These are SEM images, magnified 5 times, of the cross-sections of certain areas of the polishing pad in Comparative Example 1.

[0033] Figure 10a and Figure 10b These are SEM images, magnified 100 times, of certain regions of the polished layer of the polishing pads in Example 1 and Comparative Example 1, respectively. Detailed Implementation

[0034] Best Implementation of the Invention

[0035] The present invention will now be described in detail with reference to various embodiments and examples. The embodiments are not limited to those disclosed below. These embodiments can be modified in various forms without altering the spirit of the invention.

[0036] In this specification, the terms used to refer to the various components are used to distinguish them from each other and are not intended to limit the scope of the embodiments. Furthermore, in this specification, singular expressions are also construed to cover plural forms unless the context otherwise requires.

[0037] Throughout this specification, when a component is referred to as "containing" an element, it should be understood that, unless otherwise specifically stated, other elements may be included, rather than excluded.

[0038] In this specification, when describing a component forming above / below, or connected to or coupled to another component, it includes cases where these components are formed, connected, or coupled directly or indirectly through the other component. Furthermore, it should be understood that the terminology for "above" and "below" for each component may vary depending on the orientation of the object being observed.

[0039] All numerical ranges relating to the physical properties, dimensions, etc. of components used in this specification, unless otherwise stated, shall be understood to be modified by the word “about”.

[0040] In the numerical ranges of component dimensions, physical properties, etc., described in this specification, when individual examples are limited to the upper limit numerical range or the lower limit numerical range, it should be understood that the numerical range combining these upper and lower limits is also included in the example range.

[0041] Throughout this specification, the terms "first," "second," etc., are used to describe various components. However, these components should not be limited by these terms. These terms are used to distinguish one element from another.

[0042] Recycled polishing pads

[0043] Figure 1 This is a schematic cross-sectional view of a regenerated polishing pad according to an embodiment of the present invention.

[0044] Reference Figure 1 The recycled polishing pad (200) may include a reusable polishing layer (210), an adhesive layer (220), and a buffer layer (230). The reusable polishing layer (210), adhesive layer (220), and buffer layer (230) may be stacked in sequence.

[0045] The reused polishing layer (210) can come from polishing pads that are discarded after use in the polishing process. For example, the polishing layer contained in a waste polishing pad can be recycled after it has been used up and used in the process of preparing a recycled polishing pad (200) as described later.

[0046] A groove (215) can be formed on one side of the reused polishing layer (210). For example, the reused polishing layer (210) includes multiple grooves (215) on a first side and can be attached to a buffer layer (230) via a second side opposite to the first side. The first side can be configured as a polishing surface that comes into direct contact with the object to be polished during the polishing process. By controlling a larger flow rate of the slurry on the polishing surface through the grooves (215), the object to be polished can be mechanically polished, thereby improving polishing efficiency.

[0047] The compression ratio of the reused polishing layer (210) can be 0.9% or higher. The compression ratio of the reused polishing layer (210) can be calculated using the following Equation 1.

[0048] Equation 1

[0049] The compression ratio (%) of the polished layer is then utilized =

[0050] In Equation 1, T1 is the thickness (mm) of the reused polished layer when it is pressed with a load of 85g for 30 seconds, and T2 is the thickness (mm) of the reused polished layer when it is further pressed with a load of 885g for 3 minutes under the T1 condition. The above compression ratio can also be measured by cutting a sample prepared by cutting the reused polished layer into dimensions of 25mm in both width and length.

[0051] Since the compression rate of the reused polishing layer (210) is 0.9% or higher, the recycled polishing pad (200) can provide higher polishing rates, polishing uniformity, and smoothness, even when the polishing layer is recycled from a waste polishing pad. In addition, even if the thickness (Ta) of the reused polishing layer (210) is relatively thinner than the thickness of the polishing layer of a polishing pad that has not been used in the polishing process, it can maintain excellent physical properties and improve the polishing speed while suppressing defects such as scratches that may form on the surface of the object to be polished.

[0052] According to one implementation, the compression ratio of the reused polished layer (210) can be 0.9% or greater, 1.0% or greater, 1.2% or greater, 1.5% or greater, 1.7% or greater, or 1.8% or greater, and can be 3.0% or less, 2.8% or less, 2.6% or less, 2.5% or less, 2.3% or less, 2.2% or less, 2.1% or less, or 2.0% or less.

[0053] Specifically, the compression ratio of the reused polishing layer (210) can be from 0.9% to 3.0%, more specifically, from 0.9% to 2.8%, 0.9% to 2.6%, 0.9% to 2.1%, 1.0% to 2.1%, 1.2% to 2.1%, 1.5% to 2.0%, 1.7% to 2.0%, or 1.8% to 2.0%. Within the above ranges, the regenerated polishing pad (200) can have further enhanced mechanical properties, durability, and stability, while polishing efficiency and smoothness are further improved.

[0054] The ratio (D2 / Ta) of the depth (D2) of the groove (215) to the thickness (Ta) of the reused polishing layer (210) can be 0.7 or less. The thickness (Ta) of the reused polishing layer (210) can refer to the straight-line distance between the first and second sides of the reused polishing layer (210), and the depth (D2) of the groove (215) can refer to the depth of the recess from the first side to the second side. The thickness (Ta) of the reused polishing layer (210) and the depth (D2) of the groove (215) can be measured in mm.

[0055] Since the grooves (215) have a depth within a predetermined range relative to the thickness of the reused polishing layer (210), polishing efficiency and polishing uniformity can be further improved. In addition, debris formed on the polishing surface of the reused polishing layer (210) can be captured by the grooves (215) with the aforementioned depth, thereby enhancing the fluidity of the slurry.

[0056] The ratio (D2 / Ta) of the depth (D2) of the groove (215) to the thickness (Ta) of the reused polished layer (210) can be 0.10 or greater, 0.15 or greater, 0.20 or greater, 0.25 or greater, or 0.30 or greater, and can be 0.70 or less, 0.65 or less, 0.50 or less, 0.45 or less, 0.40 or less, or 0.35 or less.

[0057] Specifically, the ratio (D2 / Ta) can be 0.1 to 0.7, 0.1 to 0.65, 0.1 to 0.5, 0.2 to 0.5, 0.25 to 0.45, 0.30 to 0.45, 0.30 to 0.40, or 0.30 to 0.35. Within the above ranges, the polishing removal rate and polishing speed of the regenerating polishing pad (200) can be further improved, and the generation of surface defects on the polished object can be further suppressed.

[0058] According to one embodiment of the invention, even if the reused polishing layer (210) is obtained from a waste polishing pad and has a relatively thin thickness, its compressibility and groove depth still meet the above-mentioned ranges. Therefore, the recycled polishing pad (200) can maintain excellent mechanical properties and stability, and its polishing performance and smoothness can be significantly improved compared with conventional polishing pads used before the polishing process.

[0059] The ratio (D2 / Tb) of the depth (D2) of the groove (215) to the total thickness (Tb) of the regenerated polishing pad (200) can be 0.2 or less. The total thickness (Tb) of the regenerated polishing pad (200) and the depth (D2) of the groove (215) can be measured in mm. This improves non-uniformity and polishing efficiency within the wafer, while ensuring the hardness and durability required for the polishing process.

[0060] Specifically, the ratio (D2 / Tb) of the depth (D2) of the groove (215) to the total thickness (Tb) of the regenerated polishing pad (200) can be 0.2 or less, 0.19 or less, 0.18 or less, 0.17 or less, 0.16 or less, or 0.15 or less, and can be 0.05 or more, 0.07 or more, 0.08 or more, 0.09 or more, 0.10 or more, or 0.12 or more.

[0061] In one embodiment, the ratio (D2 / Tb) can be 0.05 to 0.2, 0.07 to 0.19, 0.09 to 0.18, 0.10 to 0.18, 0.10 to 0.17, 0.10 to 0.16, or 0.12 to 0.15. Within the above ranges, polishing performance can be further improved while ensuring the strength and durability of the regenerated polishing pad (200).

[0062] The depth (D2) of the groove (215) can be 0.75 mm or less. For example, the depth of the groove (215) can be 0.10 mm or more, 0.15 mm or more, 0.20 mm or more, 0.25 mm or more, 0.30 mm or more, or 0.35 mm or more, and can be 0.75 mm or less, 0.70 mm or less, 0.65 mm or less, 0.60 mm or less, 0.55 mm or less, 0.50 mm or less, 0.48 mm or less, or 0.45 mm or less. As a result, the flow rate of the polishing slurry can be controlled within the required range, and the supply and discharge of the polishing slurry can be smooth, thereby further improving polishing efficiency and uniformity.

[0063] Specifically, the depth (D2) of the groove (215) can be 0.10 mm to 0.75 mm, 0.15 mm to 0.70 mm, 0.2 mm to 0.65 mm, 0.25 mm to 0.60 mm, 0.25 mm to 0.55 mm, 0.25 mm to 0.50 mm, 0.30 mm to 0.50 mm, 0.30 mm to 0.48 mm, or 0.35 mm to 0.45 mm.

[0064] The thickness (Ta) of the reused polishing layer (210) can be 0.5 mm or more, 0.7 mm or more, 0.8 mm or more, 0.9 mm or more, or 1.0 mm or more, and can be 2.0 mm or less, 1.8 mm or less, 1.6 mm or less, 1.5 mm or less, 1.3 mm or less, or 1.2 mm or less. Specifically, the thickness (Ta) of the reused polishing layer (210) can be 0.5 mm to 2.0 mm, 0.7 mm to 1.8 mm, 0.8 mm to 1.6 mm, 0.8 mm to 1.5 mm, 0.9 mm to 1.3 mm, 0.9 mm to 1.2 mm, or 1.0 mm to 1.2 mm. Therefore, the mechanical properties of the reused polishing layer (210), such as hardness and tensile strength, can be easily controlled within the desired range, thereby further improving the stability and durability of the recycled polishing pad (200).

[0065] The total thickness (Tb) of the regenerated polishing pad (200) can be 1.5 mm or more, 1.7 mm or more, 1.8 mm or more, 1.9 mm or more, or 2.0 mm or more, and can be 6.0 mm or less, 5.0 mm or less, 4.5 mm or less, 4.0 mm or less, 3.5 mm or less, 3.0 mm or less, or 2.6 mm or less. Specifically, the total thickness of the regenerated polishing pad (200) can be 1.5 mm to 6.0 mm, 1.7 mm to 5.0 mm, 1.8 mm to 4.5 mm, 1.9 mm to 4.0 mm, 2.0 mm to 3.5 mm, 2.0 mm to 3.0 mm, or 2.0 mm to 2.6 mm.

[0066] The hardness of the polished layer (210) can be 40 Shore D to 70 Shore D, 45 Shore D to 65 Shore D, 45 Shore D to 60 Shore D, 50 Shore D to 60 Shore D, or 50 Shore D to 55 Shore D.

[0067] The density of the reused polished layer (210) can be 0.710 g / m³. 3 Up to 0.770 g / m 3 0.710g / m 3 Up to 0.760 g / m 3 0.720g / m3 Up to 0.750g / m 3 0.720g / m 3 Up to 0.745g / m 3 0.725g / m 3 Up to 0.745g / m 3 Or 0.730g / m 3 Up to 0.740 g / m 3 .

[0068] The tensile strength of the polished layer (210) can be 5 N / mm. 2 Up to 30 N / mm 2 10N / mm 2 Up to 25 N / mm 2 15N / mm 2 Up to 25 N / mm 2 or 18N / mm 2 Up to 22N / mm 2 .

[0069] The reused polishing layer (210) can have a porous structure. For example, the reused polishing layer (210) can contain multiple pores on its surface and inside. The pores support the micro-flow of the polishing slurry, thereby allowing proper control of the supply or discharge of the polishing slurry through the pores.

[0070] In some implementations, the average diameter (D) of the multiple holes 50 The diameter of the polishing pad can range from 10µm to 30µm, 10µm to 27µm, 12µm to 25µm, 14µm to 22µm, or 16µm to 20µm. The surface condition of the polishing pad, the flowability of the polishing slurry, and the polishing efficiency will vary depending on the average diameter of the pores.

[0071] The average diameter (D) of the hole can be measured by 3D CT scanning. 50 For example, using the unit area of ​​a polishing pad (1 cm²) 2 Using 3D CT scans as a benchmark, the pores inside the reused polished layer can be measured, and the diameter, area, volume, and number of pores can be calculated using CT data analysis and visualization software Volume Graphics. For example, the volume of a pore with diameter r can be calculated as 4πr. 3 / 3. Average diameter (D) 50 A pore can be defined as the diameter of the pores that constitute 50% of the volume in a volume distribution obtained by accumulating pores in order of increasing diameter.

[0072] The compression ratio of the regenerated polishing pad (200) can be 0.25% or higher. The compression ratio of the regenerated polishing pad (200) can be calculated using the following Equation 2.

[0073] Equation 2

[0074] Compression ratio (%) of regenerated polishing pads =

[0075] In Equation 2, T3 is the thickness (mm) of the regenerated polishing pad when it is pressed with a load of 85g for 30 seconds, and T4 is the thickness (mm) of the regenerated polishing pad when it is further pressed with a load of 885g for 3 minutes under the T3 condition.

[0076] Since the regenerated polishing pad (200) has a compression ratio of 0.25% or more, it can further improve the inhomogeneity and polishing rate within the wafer and suppress the generation of scratches on the object to be polished, thereby further improving the polishing quality.

[0077] In one embodiment, the compression ratio of the regenerated polishing pad (200) can be 0.25% or greater, 0.5% or greater, 0.9% or greater, 1.0% or greater, 1.2% or greater, 1.5% or greater, 1.7% or greater, 1.8% or greater, or 2.0% or greater, and can be 4.0% or less, 3.8% or less, 3.5% or less, 3.0% or less, 2.8% or less, or 2.5% or less.

[0078] Specifically, the compression ratio of the recycled polishing pad (200) can be 0.25% to 4.0%, 0.5% to 3.8%, 0.9% to 3.5%, 0.9% to 3.0%, or 1.0% to 3.0%, more specifically, 1.2% to 3.0%, 1.2% to 2.8%, 1.5% to 2.8%, 1.7% to 2.8%, 1.8% to 2.5%, or 2.0% to 2.5%. Within this range, the stability and durability of the polishing pad, the polishing rate of the object to be polished, and the polishing quality can be further improved.

[0079] In some implementations, the compression ratio of the recycled polishing pad (200) may be greater than that of the reused polishing layer (210).

[0080] The hardness of the recycled polishing pad (200) can be 35 Shore D to 55 Shore D, 38 Shore D to 55 Shore D, 40 Shore D to 50 Shore D, or 40 Shore D to 45 Shore D. In some embodiments, the hardness of the recycled polishing pad (200) can be lower than the compressibility of the reused polishing layer (210).

[0081] The reusable polishing layer (210) can be in direct contact with the adhesive layer (220). In one embodiment, the buffer layer (230), adhesive layer (220), and reusable polishing layer (210) can be laminated sequentially when in contact with each other. For example, no additional pad, such as a sub-pad or supplementary pad, may be inserted between the reusable polishing layer (210) and the buffer layer (230). The reusable polishing layer (210) has a compression ratio within the aforementioned range, and the depth of the groove (215) is adjusted to a predetermined range; therefore, it can have excellent performance even without supplementing an additional pad. The regenerated polishing pad (200) can provide enhanced polishing rates and non-uniformity within the wafer. This reduces the cost of the regeneration process, avoids environmental problems caused by the additional use of pads, and avoids yield reduction due to process complexity. Polishing pads can be made lighter, thinner, and smaller.

[0082] A buffer layer (230) is located below the reused polishing layer (210) to stably support the reused polishing layer (210) while absorbing and dispersing the impact forces applied to the reused polishing layer (210). In one embodiment, a buffer layer (230) that has not been used in the polishing process can be used.

[0083] The cushioning layer (230) may include a base layer, such as a nonwoven fabric, suede, or a porous pad. In one embodiment, the cushioning layer (230) may be prepared by forming a surface coating on the base layer with a coating composition comprising a fluoropolymer or a silane-based resin. It may also be prepared by impregnating the base layer with a resin comprising a fluoropolymer or a silane-based polyurethane resin.

[0084] The thickness of the buffer layer (230) can be, for example, 0.5 mm to 4.0 mm, 0.6 mm to 3.5 mm, 0.8 mm to 3.0 mm, or 1.0 mm to 2.0 mm. Within the above range, the recycled polishing pad (200) can be made lighter, while the buffer layer (230) can more stably support the reused polishing layer (210).

[0085] The thickness of the reused polishing layer (210) can be thinner than that of the buffer layer (230). Even if the thin polishing layer in the worn polishing pad is recycled and reused, the buffer layer (230) has a relatively thicker thickness than the reused polishing layer (210), which can stably support the reused polishing pad (200) and improve its durability.

[0086] The density of the buffer layer (230) can be 0.20 g / m³. 3 Up to 0.50g / m 3 0.25g / m 3 Up to 0.45g / m 3 0.30g / m 3Up to 0.40g / m 3 0.30g / m 3 Up to 0.37g / m 3 .

[0087] The Shore C hardness of the buffer layer (230) can be 50 Shore C to 85 Shore C, 55 Shore C to 80 Shore C, 60 Shore C to 78 Shore C, or 68 Shore C to 76 Shore C.

[0088] The adhesive layer (220) serves to bond the reused polishing layer (210) and the buffer layer (220) together. In addition, the adhesive layer (220) can prevent polishing slurry from flowing out from the top of the reused polishing layer (210) or leaking into the buffer layer (220).

[0089] In some embodiments, the adhesive layer (220) may be formed using a hot melt adhesive composition. For example, the adhesive layer (220) may comprise a hot melt adhesive with a melting point of 90°C to 130°C or 110°C to 130°C.

[0090] The hot melt adhesive composition may comprise common hot melt adhesives. In one embodiment, the hot melt adhesive may comprise polyurethane resin, polyester resin, ethylene-vinyl acetate resin, polyamide resin, and / or polyolefin resin. They may be used alone or in combination of two or more.

[0091] The thickness of the adhesive layer (220) can be, for example, 3 μm to 250 μm, 5 μm to 200 μm, 5 μm to 150 μm, 10 μm to 100 μm, 20 μm to 50 μm, or 23 μm to 40 μm. Within the above range, the bonding strength between the reused polishing layer (210) and the buffer layer (230) can be further enhanced, and the regenerated polishing pad (200) can be made lighter.

[0092] Method for preparing regenerated polishing pads

[0093] Figures 2a to 2e These are schematic cross-sectional views of a portion of the polishing pad during each step of a method for preparing a regenerated polishing pad according to one embodiment.

[0094] Figure 2a This is a schematic diagram showing the cross-section of the polishing pad before the polishing process.

[0095] Reference Figure 2a The polishing pad (100) may include a polishing layer (110), an adhesive layer (120), and a buffer layer (130) laminated in sequence. The polishing layer (110) and the buffer layer (130) may be attached to each other through the adhesive layer (120).

[0096] The polishing layer (110) may include polyurethane resin, polyester resin, polyamide resin, acrylic resin, polycarbonate resin, halogen-based resin (polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, etc.), polystyrene resin, olefin-based resin (polyethylene, polypropylene, etc.), epoxy resin, etc. Specifically, the polishing layer (110) may include polyurethane resin.

[0097] The polishing layer (110) may have a porous structure. For example, the polishing layer (110) may be formed from a mixture of raw materials comprising a polyurethane-based prepolymer, a curing agent, and a foaming agent. The polyurethane-based prepolymer may be a polymer prepared by reacting an isocyanate compound with a polyol.

[0098] "Prepolymer" typically refers to a polymer with a low molecular weight in which the degree of polymerization is adjusted to a moderate level to facilitate molding during the product's manufacturing process. Prepolymers can be molded alone or after reacting with another polymerizable compound.

[0099] The foaming agent may include a solid-phase foaming agent, a liquid-phase foaming agent, or a gas-phase foaming agent. Specifically, the foaming agent may include a solid-phase foaming agent. The pores formed on the surface and inside the polished layer (110) may originate from the foaming agent.

[0100] Curing agents may include amine compounds and / or alcohol compounds. For example, a curing agent may contain at least one compound selected from the group consisting of aromatic amines, fatty amines, aromatic alcohols, and fatty alcohols.

[0101] A groove (115) may be formed on one side of the polishing layer (110). For example, the polishing layer (110) may include a plurality of grooves (115) on a first side and may be attached to a buffer layer (130) via a second side opposite to the first side. The grooves (115) may have a predetermined depth or a greater depth D1. The depth D1 may be a depth with a performance level suitable for the polishing process. For example, if the depth of the grooves (115) is too small, the polishing rate required for the polishing process may not be achieved.

[0102] The polishing pad (100) can be used to polish an object to be polished, such as a semiconductor substrate. The first side of the polishing layer (110) can be a polishing surface, which is in direct contact with the object to be polished during the polishing process.

[0103] Figure 2b This is a schematic diagram showing the cross-section of a polishing pad that has been worn down after the polishing process.

[0104] according to Figure 2bAs the polishing process, such as CMP, progresses, the polished surface of the polished layer (110) may gradually wear down. With wear, the thickness of the polished layer (110) decreases, and the depth of the grooves (115) formed on the polished surface may decrease or collapse. Furthermore, the wear rate of the polished surface may vary depending on the polishing process conditions, the object being polished, and other regional variations. In such cases, the grooves (115) may have different depths, leading to an uneven polished surface.

[0105] When the depth of the groove (115) decreases or its shape is deformed to the point that its depth or shape can no longer be polished, the polishing pad (100) can be discarded.

[0106] The discarded polishing pad (100) can be recycled and cleaned. Impurities or foreign matter remaining on the polishing pad (100) after the polishing process can be removed by cleaning. The cleaning process is not limited, as long as it is a method that can remove impurities by cleaning the discarded polishing pad (100). For example, wet cleaning, chemical cleaning, dry cleaning, mechanical cleaning, etc. can be used.

[0107] according to Figure 2c The adhesive layer (120) and buffer layer (130) can be removed from the discarded polishing pad (100) to selectively recover the polishing layer (110). For example, the process of recovering the polishing layer (110) can be carried out by a mechanical method that mechanically peels or separates the adhesive layer (120) from the polishing layer (110), or by a chemical method that dissolves or decomposes and removes the adhesive layer (120).

[0108] according to Figure 2d The polished layer (110) can be planarized. For example, the first side of the polished layer (110) with the groove (115) formed can be planarized by cutting or milling. The groove (115) formed on the first side of the polished layer (110) can be removed by a planarization process.

[0109] In one embodiment, a planarization process may also be performed on the second side of the polished layer (110). The second side may be cut or milled to remove impurities remaining on the second side, such as adhesive components.

[0110] The thickness of the polishing layer (110) can be reduced by planarizing it to adjust it to the thickness range of the aforementioned reused polishing layer. For example, the thickness Tc of the initial polishing layer (110) can be reduced to a predetermined thickness by a polishing process, and further reduced by a planarization process. Figure 1 The range of thickness Ta described in the text.

[0111] For example, a planarization process can be performed so that the regenerated polishing pad (110) can have a thickness of 0.5 mm to 2.0 mm, 0.7 mm to 1.8 mm, 0.8 mm to 1.6 mm, 0.8 mm to 1.5 mm, 0.9 mm to 1.3 mm, 0.9 mm to 1.2 mm, or 1.0 mm to 1.2 mm.

[0112] See Figure 2e Grooves are formed on one side of the planarized polished layer (110) to prepare a reusable polished layer (210). For example, the reusable polished layer (210) may include a plurality of grooves (215) on the first side.

[0113] In one embodiment, a first side of the reusable polished layer (210) can be cut with a tip to form a groove (215). Specifically, the tip can be fixed so that it contacts the first side, and a portion of the first side can be removed by moving the reusable polished layer (210).

[0114] A cutting process using a cutting tip can be performed to make the depth of the groove (215) meet the above-mentioned range. For example, a cutting process can be performed to make the depth of the groove (215) relative to the thickness of the reuse polished layer (210) 0.10 or greater, 0.15 or greater, 0.20 or greater, 0.25 or greater, or 0.30 or greater, and 0.70 or less, 0.65 or less, 0.50 or less, 0.45 or less, 0.40 or less, or 0.35 or less.

[0115] For example, the depth of the groove (215) formed by the cutting process can be 0.10 mm or more, 0.15 mm or more, 0.20 mm or more, 0.25 mm or more, 0.30 mm or more, or 0.35 mm or more, and can be 0.75 mm or less, 0.70 mm or less, 0.65 mm or less, 0.60 mm or less, 0.55 mm or less, 0.50 mm or less, 0.48 mm or less, or 0.45 mm or less.

[0116] The groove (215) can have a concentric circular shape spaced at predetermined intervals. Alternatively, a surface machining process can be performed to machine the edges of the groove (215) into curved surfaces. The surface machining process can be performed using a grinding machine or a bearing housing.

[0117] A buffer layer (230) can be laminated onto the recycled polishing layer (210) to prepare a recycled polishing pad (200). For example, an adhesive can be applied to the second side of the recycled polishing layer (210) and / or one side of the buffer layer (230), and the recycled polishing layer (210) and the buffer layer (230) can be laminated such that the second side of the recycled polishing layer (210) and one side of the buffer layer (230) are in contact with each other, and the laminate can be pressed. Thus, as Figure 1 As shown, a regenerated polishing pad (200) with a structure in which a reusable polishing layer (210), an adhesive layer (220) and a buffer layer (230) are laminated in sequence can be prepared.

[0118] According to one embodiment of the invention, even when the polishing layer obtained from the waste polishing pad is reused, the reused polishing layer (210) has a compression ratio of 0.9% or higher, so that its mechanical properties, such as hardness, durability and pad cutting rate, as well as polishing performance, such as polishing rate and smoothness, can be substantially equivalent to or improved compared with the initial polishing pad (110) before the polishing process.

[0119] Furthermore, when a reused polishing layer is prepared using only a polishing layer obtained from a discarded polishing pad without using an additional supplementary pad, the thickness (Ta) of the reused polishing layer (210) becomes thinner than the thickness (Tc) of the initial polishing layer (110). According to one embodiment of the invention, since the reused polishing layer (210) has the compression ratio described above, and since the grooves (215) are formed to have a predetermined depth ratio relative to the thickness of the reused polishing layer (210), enhanced physical properties and polishing performance can be achieved.

[0120] In one embodiment, during the step of recovering the polishing layer (110) from the waste polishing pad (100), a polishing layer with a compression ratio of 0.9% or greater may be selected. The compression ratio of the polishing layer can be calculated using the following Equation 3.

[0121] Equation 3

[0122] Compression ratio of polished layer (%) =

[0123] In Equation 3, T5 is the thickness (mm) of the polished layer when the polished layer is pressed with a load of 85g for 30 seconds, and T6 is the thickness (mm) of the polished layer when the polished layer is further pressed with a load of 885g for 3 minutes under the T5 condition.

[0124] For example, as the polishing process progresses, the compression ratio of the polishing layer changes from its initial value. Therefore, the compression ratio of the polishing layer used in discarded polishing pads may have a different value than the initial one. Since polishing layers with a compression ratio of 0.9% or higher are selectively recovered from discarded polishing pads, these layers can be directly used in the reuse process without additional processing steps to adjust the compression ratio. Therefore, processing costs can be reduced, and recycled polishing pads with the desired performance and polishing characteristics can be obtained more easily.

[0125] In one embodiment, the compression ratio of the polishing layer (110) obtained from the waste polishing pad (100) can be substantially the same as the compression ratio of the reused polishing layer. For example, it can be 0.9% to 3.0%, 0.9% to 2.8%, 0.9% to 2.6%, 0.9% to 2.2%, 0.9% to 2.1%, 1.0% to 2.1%, 1.2% to 2.1%, 1.5% to 2.0%, 1.7% to 2.0%, or 1.8% to 2.0%.

[0126] According to one embodiment of the invention, since the recycled polishing pad includes a reused polishing layer with a specific range of compression ratios, its mechanical properties and polishing rate can be further improved while reusing the waste polishing pad. Because the surface defect characteristics appearing on the semiconductor substrate surface can be improved, high-quality semiconductor devices can be efficiently manufactured using the recycled polishing pad.

[0127] The present invention will be described in detail below through the following embodiments. However, these embodiments are for illustrative purposes only, and the scope of the invention is not limited thereto.

[0128] Embodiments of the present invention

[0129] Example 1

[0130] (1) Preparation of polishing pad

[0131] Polishing pads are prepared using a casting apparatus equipped with an injection line containing polyurethane-based prepolymer, curing agent, inert gas, and reaction rate control agent.

[0132] Specifically, a polyurethane-based prepolymer (SKC) containing 9.3% by weight of unreacted NCO is loaded into a prepolymer tank, and 4,4'-methylenebis(2-chloroaniline) (Ishihara Sangyo Co., Ltd.) is loaded into a curing agent tank, using nitrogen (N2) as an inert gas. Additionally, 1 part by weight of a solid-phase blowing agent (AkzoNobel) and 1 part by weight of a silicone-based surfactant (Evonik) are premixed relative to 100 parts by weight of the polyurethane-based prepolymer and then added to the prepolymer tank.

[0133] The raw materials are agitated as they are fed to the mixing head at a constant rate through their respective delivery lines. The molar equivalent ratio of NCO groups in the polyurethane-based prepolymer to reactive groups in the curing agent is adjusted to 1:1, and the total feed rate is maintained at 10 kg / min. The mixed raw materials are injected into a mold (1,000 mm × 1,000 mm × 3 mm) and cured to obtain a molded product.

[0134] The top and bottom of the molded part were each cut to a thickness of 0.5 mm to obtain a polished layer with a thickness of 2.03 mm. The compression rate of the polished layer was measured to be 0.83%. Using a tip, concentric grooves with a width of 0.45 mm and a depth of 0.85 mm were formed on one side of the polished layer at equal intervals of 3.0 mm.

[0135] A 1.3 mm thick buffer layer is prepared by impregnating polyester nonwoven fabric with polyurethane resin. The polishing layer and the buffer layer are bonded together using hot melt adhesive to form a polishing pad (thickness: 3.43 mm), which has a structure of polishing layer, adhesive layer and buffer layer.

[0136] (2) Preparation of waste polishing pads

[0137] Secure the polishing pad to the platen of the CMP equipment, and position the silicon wafer (diameter: 300 mm) with its tungsten (W) film facing down. Then perform the CMP process (polishing load: 2.8 psi, application of calcined silica slurry). Repeat the CMP process until the polishing pad is determined to be unusable, and collect the used polishing pads (waste polishing pads).

[0138] (3) Preparation of regenerated polishing pads

[0139] Remove the buffer and adhesive layers from the waste polishing pad, and select and recycle the polishing layer with a compression ratio of 1.89%. Planarize the polishing layer to prepare a reusable polishing layer with a thickness of 1.03 mm. Using a tip, form concentric grooves with a width of 0.45 mm and a depth of 0.35 mm at equal intervals of 3.0 mm on one side of the reusable polishing layer.

[0140] A recycled polishing pad containing a reused polishing layer as the polishing layer was prepared. Specifically, a buffer layer with a thickness of 1.3 mm was prepared by impregnating polyester nonwoven fabric with polyurethane resin. The reused polishing layer and the buffer layer were bonded together using hot melt adhesive to form a recycled polishing pad (thickness: 2.43 mm) having a structure of a reused polishing layer, an adhesive layer, and a buffer layer.

[0141] Example 2

[0142] The recycled polishing pad (thickness: 2.43 mm) was prepared by the same method as in Example 1, except that in step (3) of Example 1, a polishing layer with a compression rate of 1.0% was recovered from the waste polishing pad and planarized to prepare a reused polishing layer with a thickness of 1.03 mm.

[0143] Example 3

[0144] The recycled polishing pad (thickness: 2.43 mm) was prepared by the same method as in Example 1, except that in step (3) of Example 1, a polishing layer with a compression rate of 2.2% was recovered from the waste polishing pad and planarized to prepare a reused polishing layer with a thickness of 1.03 mm.

[0145] Example 4

[0146] Regenerated polishing pad (thickness: prepared by the same method as in Example 1, except that in step (3) of Example 1, concentric grooves with a width of 0.45 mm and a depth of 0.20 mm are formed at equal intervals of 3.0 mm on one side of the reused polishing layer.

[0147] Example 5

[0148] Regenerated polishing pad (thickness: prepared by the same method as in Example 1, except that in step (3) of Example 1, concentric grooves with a width of 0.45 mm and a depth of 0.65 mm are formed at equal intervals of 3.0 mm on one side of the reused polishing layer.

[0149] Comparative Example 1

[0150] The polishing pad (thickness: 3.43 mm) was prepared in the same manner as step (1) of Example 1.

[0151] Measurement of the physical properties of polishing pads

[0152] (1) Measurement of compressibility

[0153] The compressibility of each polished layer, the reused polished layer, and the recycled polishing pad was measured using a thickness gauge (129-E, YASUDA, Yasuda Corporation) at 23°C ± 2°C and 50% ± 5% humidity.

[0154] Specifically, a weight of 85 g was applied to each polished layer (reused polished layer) sample, each measuring 2.5 cm × 2.5 cm, for 30 seconds, and the sample thickness (T1 or T5) was measured in mm. The weight was then increased to 885 g, and the sample thickness (T2 or T6) was measured in mm after 3 minutes. The compressibility of the polished layer or reused polished layer was measured using Equation 1 or Equation 3 above.

[0155] In addition, under the same conditions, the thicknesses T3 (mm) and T4 (mm) of each polishing pad sample with a length and width of 2.5cm × 2.5cm were measured, and the compressibility of the polishing pad was measured using Equation 2 above.

[0156] (2) Measurement of hardness

[0157] Polishing pad samples measuring 2cm x 2cm were left to stand for 16 hours at 25℃ and 50±5% humidity. Subsequently, the Shore D hardness of each polishing pad and each polishing layer was measured using a D-type hardness tester.

[0158] (3) Measurement of density

[0159] The density of each polishing layer and each polishing pad was measured at 20°C. The density was measured using Archimedes' principle.

[0160] Table 1

[0161]

[0162] Test Example 1: Polishing Rate Evaluation 1

[0163] Each polishing pad was fixed to the platen of the CMP equipment, and the silicon wafer (diameter: 300 mm) was positioned with its silicon oxide layer facing down. The CMP process was then performed. Specifically, the silicon oxide layer was polished under the polishing loads shown in Table 2 below, while the platen rotated at 150 rpm for 60 seconds, and calcined silica slurry (ACESOL 2580) was supplied to the polishing pads at a rate of 190 ml / min. After polishing, the silicon wafer was removed from the carrier, placed in a rotary dryer, rinsed with deionized water, and then dried for 15 seconds. The thickness difference of the silicon oxide layer before and after polishing (polishing thickness) at 98 locations on each dried silicon wafer was measured using a contact surface resistance measuring device (4 probes). The average polishing thickness was calculated based on the measurements. The polishing rate (removal rate) was calculated using the following equation:

[0164] Polishing rate (Å / min) = Average polishing thickness of silicon wafer (silicon oxide layer) (Å) / Polishing time (min)

[0165] In Example 1 and Comparative Example 1, the region from the center of the silicon wafer to a radius of 60 mm was defined as the center region, the region from a radius of 60 mm to a radius of 130 mm was defined as the middle region, and the region from a radius of 130 mm to a radius of 150 mm was defined as the edge region. The polishing rate of the center region was calculated as the average of the values ​​(polishing thickness) measured in the center region. The polishing rate of the middle region was calculated as the average of the values ​​measured in the middle region. The polishing rate of the edge region was calculated as the average of the values ​​measured in the edge region.

[0166] Figures 3a to 3c The image shows the polishing rates for the center, middle, and edge regions. Specifically, Figure 3a The polishing rate is shown as measured at a polishing load of 1.7 psi. Figure 3b The polishing rate is shown as measured at a polishing load of 2.7 psi. Figure 3c The polishing rate is shown as measured at a polishing load of 3.7 psi.

[0167] also, Figures 4a to 4c The figure shows a curve showing the distribution of polishing rate relative to distance from the center.

[0168] according to Figures 3a to 3c Examples 4a to 4c show that when the polishing process was performed using the polishing pad of Example 1, a higher polishing rate than Comparative Example 1 was achieved under all evaluated polishing loads. Furthermore, it was determined that the polishing rate of Example 1 was more uniform across the entire area of ​​the silicon wafer than that of Comparative Example 1, indicating superior inhomogeneity within the wafer.

[0169] Test Example 2: Intra-wafer non-uniformity

[0170] Based on the measured values ​​obtained from the evaluation of polishing rate 1 in Test Example 1, the in-wafer non-uniformity (WIWNU) is calculated according to the following equation.

[0171] Intra-wafer non-uniformity (%) = (Standard deviation of polishing thickness (Å) / Average polishing thickness (Å)) × 100

[0172] Test Example 3: Polishing Rate Evaluation 2

[0173] Except that the slurry was changed to cerium dioxide slurry (ACS-580), the polishing rate was evaluated in the same manner as in Test Example 1.

[0174] In Example 1 and Comparative Example 1, the polishing rates of the center, middle, and edge regions of each silicon wafer were measured and are shown in the figures. Figures 5a to 5c Specifically, Figure 5a The polishing rate is shown as measured at a polishing load of 1.7 psi. Figure 5b The polishing rate is shown as measured at a polishing load of 2.7 psi. Figure 5c The polishing rate is shown as measured at a polishing load of 3.7 psi.

[0175] according to Figures 5a to 5c The polishing pad of Example 1 has a polishing rate that is substantially similar to that of the polishing pad of Comparative Example 1, indicating that the polishing uniformity is maintained excellently.

[0176] Test Example 4: Polishing Rate Evaluation 3

[0177] Except that the object to be polished was changed to a tungsten (W) layer on a silicon wafer and the slurry was changed to a silica slurry (SP6730), the polishing rate was evaluated in the same manner as in Test Example 1. The difference in tungsten layer thickness before and after polishing was measured, and the polishing rate was calculated according to the following equation.

[0178] Polishing rate (Å / min) = Silicon wafer (tungsten layer) polishing thickness (Å) / Polishing time (min)

[0179] In Example 1 and Comparative Example 1, the polishing rates of the center, middle, and edge regions of each silicon wafer were measured and are shown in the figures. Figure 6a and 6b Specifically, Figure 6a The polishing rate is shown as measured at a polishing load of 1.7 psi. Figure 6b The polishing rate is shown as measured at a polishing load of 2.7 psi.

[0180] also, Figures 4a to 4c Curves 7a and 7b, showing the distribution of polishing rate relative to distance from the center, are shown in the figure.

[0181] according to Figure 6a , 6b Examples 1, 7a and 7b, show a higher polishing rate than Comparative Example 1, while also indicating a relatively uniform polishing rate.

[0182] Table 2

[0183]

[0184] According to Table 2 above, when the polishing process is performed using the polishing pad of Example 1, a higher polishing rate and lower in-wafer non-uniformity are achieved compared to Comparative Example 1, which indicates that the polishing efficiency and uniformity are both excellent.

[0185] Test Example 5: Surface Roughness of Polishing Pad

[0186] The surface roughness of the polishing pads in Example 1 and Comparative Example 1 was measured using an optical surface roughness meter (Contour GT, Bruker). Specifically, the surface roughness was measured with the following scan options: measurement mode VSI / VXI, eyepiece magnification 5x, objective magnification 1.5x, scan speed 1x, back scan distance 10 μm, length 80 μm, and threshold 5%. The accumulated data were plotted against the measured height per unit area to obtain the area material ratio curve of the surface roughness. The S-parameter was derived, which is a parameter that converts the area material ratio curve into depth (height). Specifically, the core roughness depth (Sa), the reduced valley depth (Svk), and the reduced peak height (Spk) of each polishing pad were measured.

[0187] The evaluation results are shown in Table 3 below.

[0188] Test Example 6: Fragment Size

[0189] Polishing pads from Example 1 and Comparative Example 1 were respectively placed on the pressure plates of a CMP polishing apparatus. Subsequently, excluding carrier operations, only conditioner and deionized water (DIW) were used to collect polishing layer debris. The polishing layer was conditioned under the conditions of a pressure plate speed of 93 rpm, a conditioner load of 9 lbs., a rotational speed of 64 rpm, and a sweeping speed of 19 times / min, while supplying deionized water at a rate of 300 cc / min. During the conditionation process, polishing layer debris and deionized water were collected. The particle size distribution of the collected debris was measured using a particle size analyzer (Mastersize 3000, Malvern, Malvern Instruments, UK) and a medium-capacity automatic disperser (Hydro MV, Malvern). In the particle size distribution, when the debris was arranged in order of increasing particle size, the D10, D50, and D90 of the debris were measured at the 10%, 50%, and 90% points, respectively. The analyzer was set to use polyurethane with a refractive index of 1.55 as the analyte, deionized water with a refractive index of 1.33 as the dispersant, and a stirring speed of 2,500 rpm.

[0190] The evaluation results are shown in Table 3 below.

[0191] Test Example 7: Pad Cutting Rate of Polishing Pad

[0192] The polishing pads of Example 1 and Comparative Example 1 were pretreated by spraying deionized water onto them for 10 minutes. Then, each polishing pad was sprayed with deionized water for 1 hour while adjustment was performed, and the thickness change (μm / hr) of the polishing pads before and after adjustment was measured. The device used for pre-adjustment was a CTS AP-300HM. The pressure was 6 lbf, the rotation speed was 100 rpm to 110 rpm, and the disk used was a Sasol LPX-DS2.

[0193] The evaluation results are shown in Table 3 below.

[0194] Table 3

[0195]

[0196] According to Table 3 above, although the polishing pad of Example 1 contains a reused polishing layer, it still exhibits excellent overall performance. Specifically, its surface roughness, fragment size, and polishing pad cutting rate are substantially similar to those of Comparative Example 1, which has a new polishing layer.

[0197] Test Example 8: Evaluation of the Cross-section and Surface of the Polishing Pad

[0198] The cross-sections and surfaces of the polishing pads in Example 1 and Comparative Example 1 were observed using a scanning electron microscope (SEM). Figure 8a and Figure 8b These are SEM images of certain areas of the cross-section of the polishing pad in Example 1, magnified 5 times. Figure 9a and Figure 9b These are SEM images of certain areas of the polishing pad cross-section in Comparative Example 1, magnified 5 times.

[0199] Specifically, Figure 8a and 9a This is a cross-sectional view of a certain area of ​​the polishing pad taken before the polishing rate assessment. Figure 8b and 9b These are cross-sectional views of certain areas of the polishing pad taken after the polishing rate evaluation, based on Test Example 1.

[0200] according to Figure 8a and 8b As shown, in Example 1, even after the polishing rate evaluation, the shape of the polishing pad did not change significantly, and the grooves and polishing layers had shapes, depths and thicknesses that could be reused in the polishing process.

[0201] In comparison, according to Figure 9a and 9b In Comparative Example 1, the shape of the polishing pad changed after the polishing rate evaluation, and it had a shape that was not suitable for use in the polishing process due to groove collapse or gap filling.

[0202] Figure 10a and Figure 10b These are SEM images, magnified 100 times, of certain regions of the polished layer of the polishing pads in Example 1 and Comparative Example 1, respectively.

[0203] according to Figure 10a The polishing layer of the polishing pad in Example 1 contains pores, and its porosity is substantially similar to that of the polishing layer of the initial polishing pad not used in the polishing process of Comparative Example 1.

[0204] Test Example 9: Evaluation of Polishing Rate Related to Compressibility and Groove Depth

[0205] For the polishing pads of Examples 1 to 5 and Comparative Example 1, the polishing rate (Å / min) of the silicon oxide layer was determined using the same method as the evaluation of polishing rate 1 in Test Example 1 and polishing rate 2 in Test Example 3. The evaluation results are shown in Tables 4 and 5 below.

[0206] Table 4

[0207]

[0208] Table 5

[0209]

[0210] According to Table 4 above, the polishing rate varies depending on the compression ratio of the polishing layer. Specifically, in Examples 1 to 3, the depth of the groove, the thickness of the polishing layer, and the thickness of the polishing pad are basically the same, but the compression ratio of the polishing layer is different, resulting in different polishing rates of the wafer during the polishing process.

[0211] According to Table 5 above, the polishing rate of the wafer changes as the ratio of groove depth to polishing layer thickness changes. Specifically, in Examples 1 to 3, the compression ratio of the polishing layer, the thickness of the polishing layer, and the thickness of the polishing pad are basically the same. However, because the grooves have different depths, and the groove depth is different relative to the thickness of the polishing layer, the polishing rate of the wafer changes during the polishing process.

[0212] Therefore, by controlling the compression ratio of the polishing layer and / or the groove depth relative to the thickness of the polishing layer and the polishing pad, the polishing pad can have excellent physical properties and can provide the desired polishing characteristics in the polishing process.

[0213] [Explanation of Labels in the Attached Image]

[0214] 100: Polishing pad, 110: Polishing layer, 115, 215: Groove, 120, 220: Adhesive layer, 130, 230: Buffer layer, 200: Recycled polishing pad, 210: Reusable polishing layer.

Claims

1. A regenerative polishing pad, comprising: a buffer layer; an adhesive layer formed on the buffer layer; and a reutilization polishing layer attached to the adhesive layer and having a groove on one side, wherein the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and Recovery rate (%) of the polished layer the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and 【Equation 1】 In Equation 1, T1 is the thickness (mm) of the reutilization polishing layer measured when the reutilization polishing layer is pressed for 30 seconds with a load of 85 g. T2 is the thickness (mm) of the reutilization polishing layer measured when the reutilization polishing layer is further pressed for 3 minutes with a load of 885 g after measuring T1. Compression rate (%) of the regenerative polishing pad = 2. The reutilization polishing pad according to claim 1, wherein the ratio of the depth of the groove to the thickness of the reutilization polishing layer is 0.1 to 0.

7.

3. The reutilization polishing pad according to claim 1, wherein the depth of the groove is 0.10 mm to 0.75 mm.

6. The regenerative polishing pad of claim 1, wherein, 4. The reutilization polishing pad according to claim 1, wherein the compression rate of the reutilization polishing layer is 0.9% to 3.0%.

7. The regenerative polishing pad of claim 1, wherein, 5. The reutilization polishing pad according to claim 1, wherein the reutilization polishing pad has a compression rate of 0.25% or more calculated by Equation 2 below: 【Equation 2】 In Equation 2, T3 is the thickness (mm) of the reutilization polishing pad measured when the reutilization polishing pad is pressed for 30 seconds with a load of 85 g, and T4 is the thickness (mm) of the reutilization polishing pad measured when the reutilization polishing pad is further pressed for 3 minutes with a load of 885 g after measuring T3. The reutilization polishing layer has a hardness of 40 Shore D to 70 Shore D. The reutilization polishing layer has a hardness of 40 Shore D to 70 Shore D.

8. A method of manufacturing a reutilization polishing pad, comprising: reclaiming a polishing layer from a polishing pad used in a CMP process; planarizing one side of the polishing layer; Recovery rate (%) of the polished layer forming a groove on one side of the planarized polishing layer to manufacture a reutilization polishing layer; and attaching a buffer layer to the other side of the reutilization polishing layer using an adhesive, wherein the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and the reutilization polishing layer has a compression rate of 0.9% or more calculated by Equation 1 below, and 【Equation 1】 In Equation 1, T1 is the thickness (mm) of the reutilization polishing layer measured when the reutilization polishing layer is pressed for 30 seconds with a load of 85 g, and T2 is the thickness (mm) of the reutilization polishing layer measured when the reutilization polishing layer is further pressed for 3 minutes with a load of 885 g after measuring T1.

9. The method of manufacturing a reutilization polishing pad according to claim 8, wherein in the step of forming a groove, the groove is formed so that the depth of the groove is 0.7 times or less of the thickness of the reutilization polishing layer.

10. The method of manufacturing a reutilization polishing pad according to claim 8, wherein the step of reclaiming a polishing layer includes selecting a polishing layer having a compression rate of 0.9% or more calculated by Equation 3 from the polishing layer obtained from a polishing pad used in a CMP process: 【Equation 3】 In Equation 3, T is the thickness (mm) of the polishing layer measured when the polishing layer is pressed for 30 seconds with a load of 85 g, and Compression rate (%) of the polished layer In Equation 3, T5 is the thickness (mm) of the polishing layer measured when the polishing layer is pressed for 30 seconds with a load of 85 g; T6 is the thickness (mm) of the polishing layer measured when the polishing layer is further pressed for 3 minutes with a load of 885 g after measuring T5.

Images