Polishing pad with excellent recyclability and pyrolysis oil obtained therefrom

Abstract

To provide a polishing pad in which the content of residual chlorine components upon pyrolysis is controlled to realize excellent physical properties.SOLUTION: The invention relates to a polishing pad that comprises a polishing layer. When pyrolysis oil obtained by pyrolyzing the polishing layer at 320°C for 6 hours is analyzed by combustion-ion chromatography (C-IC) in accordance with the IEC 62321-3-2 standard, the content of chlorine (Cl) is less than 10000 ppm.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] An implementation example relates to a polishing pad used in a chemical mechanical planarization (CMP) process of a semiconductor element and a pyrolysis oil obtained from the polishing pad.

Background Art

[0002] Among semiconductor manufacturing processes, in a chemical mechanical polishing (CMP) process, a semiconductor substrate such as a wafer is attached to a head and brought into contact with the surface of a polishing pad fixed on a platen, and the platen and the head are relatively moved to planarize the uneven portions on the surface of the semiconductor substrate.

[0003] In such a CMP process, since the polishing pad greatly affects the surface processing quality of the semiconductor substrate, it is required to have stable physical properties. In particular, since the polishing rate of the CMP process can vary sensitively depending on the components contained in the polishing pad and their physical properties, it is necessary to optimize the components contained in the polishing pad and their physical properties.

[0004] On the other hand, as environmental problems have recently become more serious, attempts have been made to recycle used polishing pads. However, it is difficult to process the polishing pad for recycling (for example, melting process using heat), and the discarded polyurethane polishing pad is not decomposed, causing environmental problems. Therefore, attempts have been made to utilize the pyrolysis oil recovered through thermal decomposition of the waste polishing pad as an energy source, or further to manufacture it into a polyol which is a raw material of the polishing pad and use it for the regeneration of the polishing pad. On the other hand, the polishing pad generally contains highly toxic halogen elements such as chlorine, and such components remain even after thermal decomposition, making recycling difficult.

[0005] Therefore, it is necessary to develop a technology that has excellent physical properties of the polishing pad and performance in the CMP process, but can increase the recycling rate by thermal decomposition after use.

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] As a result of research to solve the above conventional problems, the inventors were able to realize a polishing pad in which the chlorine content remaining during the thermal decomposition of the polyurethane-based material was adjusted within a specific range. As a result, while maintaining excellent physical properties and performance of the polishing pad, the occurrence of defects and scratches during the CMP process could be minimized. In addition, by using the pyrolysis oil obtained by the thermal decomposition treatment of such a polishing pad as an energy source, or even manufacturing it as a raw material for the polishing pad, the environmental load can be reduced by recycling it as an organic resource.

[0008] Therefore, the realization example aims to provide a polishing pad in which the content of the residual chlorine component after thermal decomposition is controlled and which can exhibit excellent physical properties. In addition, the realization example aims to provide a pyrolysis oil obtained by thermally decomposing the polishing layer of the polishing pad and a method for producing the same.

Means for Solving the Problems

[0009] According to an example for solving the above problems, there is provided a polishing pad including a polishing layer, wherein the chlorine (Cl) content analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard of the pyrolysis oil obtained by thermally decomposing the polishing layer at 320°C for 6 hours is less than 10,000 ppm.

[0010] According to another implementation example, there is provided a pyrolysis oil obtained from the polishing layer of a polishing pad, wherein the chlorine (Cl) content analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard is less than 10,000 ppm.

Advantages of the Invention

[0011] In the polishing pad according to the above implementation example, the chlorine content remaining during the pyrolysis of the polishing layer is adjusted within a specific range, so that while maintaining excellent physical properties and performance of the polishing pad, the occurrence of defects and scratches during the CMP process can be minimized. Therefore, when the CMP process is performed using the polishing pad, a semiconductor substrate (for example, a wafer) with a high polishing rate and excellent surface processing quality can be provided.

[0012] In addition, the pyrolysis oil according to the above implementation example is obtained by pyrolyzing the polishing layer of the polishing pad and can be used as a high-quality energy source through processes such as purification. Therefore, the implementation example can contribute to improving environmental problems while increasing the recycling rate of the polishing pad.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0014] In the following description of implementation examples, if a specific description of a related known configuration or function is determined to obscure the gist of the implementation example, the detailed description thereof will be omitted. Also, the size of each component in the drawings may be exaggerated or omitted for the purpose of explanation and may differ from the actual size applied.

[0015] In this specification, the description that one component is formed above / below another component, or is connected or coupled to each other, includes all cases where these components are formed, connected, or coupled directly or indirectly via other components. Also, it should be understood that the criteria regarding above / below each component may vary depending on the direction of observing the object.

[0016] In this specification, the terms referring to each component are used to distinguish them from other components and are not intended to limit the implementation examples. Also, in this specification, the singular expression includes the plural expression unless the context clearly has a different meaning.

[0017] In this specification, terms such as first, second, etc. are used to describe various components, and the components should not be limited by the terms. The terms are used for the purpose of distinguishing one component from another.

[0018] The description "comprising" in this specification is for specifying characteristics, regions, stages, processes, elements, components, and does not exclude the existence or addition of other characteristics, regions, stages, processes, elements, components unless otherwise stated.

[0019] Regarding the molecular weight of the compounds and the molecular weight of the polymers described in this specification, for convenience, the unit of molar mass is described, but it may be understood as the relative mass based on carbon-12. Also, the molecular weight of the polymers described in this specification may be interpreted as the number average molecular weight or the weight average molecular weight, for example, it may be interpreted as the number average molecular weight.

[0020] In the numerical ranges that limit the sizes, physical properties, etc. of the components described in this specification, when a numerical range limited only by the upper limit value and a numerical range limited only by the lower limit value are separately exemplified, it should be understood that the numerical range combined with these upper limit values and lower limit values is also included in the exemplified range.

[0021] [Polishing Pad] The polishing pad according to one implementation example includes a polishing layer. FIG. 1 shows a cross-sectional view of a polishing pad according to one implementation example. Referring to FIG. 1, the polishing pad may include a support layer 30 below the polishing layer 10. Also, an adhesive layer 20 may be inserted between the polishing layer and the support layer.

[0022] In one implementation example, the chlorine (Cl) content analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard of the pyrolysis oil obtained by pyrolyzing the polishing layer at 320 ° C for 6 hours is 10,000 ppm or less.

[0023] The IEC62321-3-2 standard using combustion ion chromatography (C-IC) is a halogen component screening test method developed in response to regulations on halogen use. The test method is superior in precision / accuracy and reproducibility compared to conventional halogen analysis methods (for example, oxygen bomb-IC, oxygen flask-IC), and is automated, so the reliability of the test results is excellent.

[0024] The chlorine content in the pyrolysis oil obtained from the polishing layer of the polishing pad according to the implementation example is 10,000 ppm or less, and may be, for example, 5,000 ppm or less, 1,000 ppm or less, 500 ppm or less, 200 ppm or less, 100 ppm or less, 80 ppm or less, 50 ppm or less, 30 ppm or less, 20 ppm or less, or 10 ppm or less. By adjusting the chlorine content within the above range, while maintaining excellent various physical properties and performance of the polishing pad, the size of debris can be reduced to minimize the occurrence of defects and scratches during the CMP process.

[0025] Furthermore, the lower limit of the chlorine content range in the pyrolysis oil obtained from the polishing layer of the polishing pad according to the above embodiment can be, for example, 0 ppm or more, more than 0 ppm, 1 ppm or more, 2 ppm or more, 3 ppm or more, 4 ppm or more, or 5 ppm or more. Within this range, debris will aggregate to an appropriate size, the surface area and adsorption force will be adjusted, adsorption and desorption on the wafer and pad will be facilitated, the electrical attraction / chuck force will be adjusted, and the polishing performance can be made more appropriate.

[0026] As a specific example, the chlorine (Cl) content of the pyrolysis oil obtained by pyrolyzing the polishing layer at 320°C for 6 hours and analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard can be 1 ppm to 10,000 ppm. As another specific example, the chlorine (Cl) content of the pyrolysis oil analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard can be 1 ppm to 1,000 ppm. As still another specific example, the chlorine (Cl) content of the pyrolysis oil analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard can be 1 ppm to 100 ppm. As still another specific example, the chlorine (Cl) content of the pyrolysis oil analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard can be 1 ppm to 10 ppm.

[0027] Thus, by adjusting the chlorine content of the polishing pad according to the above embodiment within a specific range, the size of debris can be reduced, and the occurrence of defects and scratches during the CMP process can be minimized.

[0028] Also, in one implementation example, the polishing pad contains sulfur (S) within a specific content range during pyrolysis, thereby maintaining excellent physical properties and performance of the polishing pad, adjusting the size of debris generated during the CMP process, reducing the occurrence of defects and scratches, and improving process stability. For example, when analyzing the pyrolysis oil with an elemental analyzer, the sulfur (S) content can be 1 ppm to 100 ppm. Specifically, when analyzing the pyrolysis oil with an elemental analyzer, the sulfur (S) content can be 3 ppm to 100 ppm. More specifically, when analyzing the pyrolysis oil with an elemental analyzer, the sulfur (S) content can be 3 ppm to 10 ppm.

[0029] Also, when pyrolyzing the polishing layer of the polishing pad according to one implementation example, the residual metal components can be included within a specific content range. For example, when analyzing the pyrolysis oil obtained by pyrolyzing the polishing layer at 320 °C for 6 hours with an ICP-OES (inductively coupled plasma-optical emission spectrometer), the total content of metal components can be 1 ppm to 3000 ppm. Specifically, when analyzing the pyrolysis oil with an ICP-OES, the total content of metal components can be 1 ppm to 3000 ppm, 1 ppm to 1500 ppm, 1 ppm to 1000 ppm, 1 ppm to 100 ppm, or 1 ppm to 10 ppm. More specifically, when analyzing the pyrolysis oil with an ICP-OES, the total content of metal components can be 3 ppm to 3000 ppm, 3 ppm to 1500 ppm, 3 ppm to 1000 ppm, 3 ppm to 100 ppm, or 3 ppm to 10 ppm.

[0030] The metal components are derived from catalyst components used during the manufacture of the polishing pad, etc. The detection of metal components can mean that a polishing pad with excellent physical properties has been manufactured. Specifically, when the content of the metal components contained in the pyrolysis oil obtained by pyrolyzing the polishing layer is within the above range, the polishing pad can exhibit high strength, hardness, etc.

[0031] On the one hand, the metal component is not particularly limited, but specifically, it may contain one or more selected from the group consisting of aluminum (Al), iron (Fe), cadmium (Cd), chromium (Cr), lead (Pb), and arsenic (As). In one specific example, when analyzing the pyrolysis oil by ICP-OES, the content of aluminum (Al) can be 1 ppm to 100 ppm, 1 ppm to 50 ppm, 1 ppm to 10 ppm, or 1 ppm to 5 ppm. In another specific example, when analyzing the pyrolysis oil by ICP-OES, the content of iron (Fe) can be 1 ppm to 100 ppm, 1 ppm to 50 ppm, 1 ppm to 10 ppm, or 1 ppm to 5 ppm. As a more specific example, when analyzing the pyrolysis oil by ICP-OES, the contents of aluminum (Al) and iron (Fe) can each be 1 ppm to 50 ppm.

[0032] Also, when analyzing the pyrolysis oil by ICP-OES, the content of silicon (Si) is 1 ppm to 3000 ppm, specifically, it can be 100 ppm to 3000 ppm.

[0033] Also, the pyrolysis oil according to one implementation example may contain various substances, and when this is distilled, each substance contained in the pyrolysis oil may exhibit a boiling point within a specific range. For example, when analyzing the pyrolysis oil (substances contained in the pyrolysis oil) based on the ASTM D2887 (specifically, ASTM D2887-19a) standard, the initial boiling point can be 10 °C to 50 °C, and the final boiling point can be 400 °C to 500 °C. Specifically, the initial boiling point of the pyrolysis oil can be 30 °C to 40 °C, and the final boiling point of the pyrolysis oil can be 430 °C to 460 °C.

[0034] When the pyrolysis oil is distilled to analyze its boiling point, the boiling point of the substance accounting for 5% by weight of the pyrolysis oil can be 10°C to 69°C. The boiling point of the substance accounting for 10% by weight of the pyrolysis oil can be 69°C to 73°C. The boiling point of the substance accounting for 20% by weight of the pyrolysis oil can be 73°C to 78°C. The boiling point of the substance accounting for 30% by weight of the pyrolysis oil can be 78°C to 87°C. The boiling point of the substance accounting for 40% by weight of the pyrolysis oil can be 87°C to 112°C. The boiling point of the substance accounting for 50% by weight of the pyrolysis oil can be 112°C to 137°C. The boiling point of the substance accounting for 60% by weight of the pyrolysis oil can be 137°C to 163°C. The boiling point of the substance accounting for 70% by weight of the pyrolysis oil can be 163°C to 199°C. The boiling point of the substance accounting for 80% by weight of the pyrolysis oil can be 199°C to 298°C. The boiling point of the substance accounting for 90% by weight of the pyrolysis oil can be 298°C to 358°C. The boiling point of the substance accounting for 95% by weight of the pyrolysis oil can be 358°C to 500°C.

[0035] In addition, the polishing pad according to the above embodiments is excellent in performance and various physical properties. When polishing the silicon oxide film of a silicon wafer in ceria slurry using the polishing pad, the polishing rate can be 2000 Å / min or more, 2200 Å / min or more, 2300 Å / min or more, or 2400 Å / min or more, and can also be 3000 Å / min or less, 2800 Å / min or less, 2600 Å / min or less, or 2500 Å / min or less. As an example, when polishing the silicon oxide film of a silicon wafer in ceria slurry using the polishing pad, the following polishing rate can be 2200 Å / min to 2600 Å / min. Polishing rate (Å / min) = Change in film thickness before and after polishing (Å) / Polishing time (min)

[0036] Specifically, the polishing rate can be the polishing rate for a 300 mm diameter silicon wafer on which silicon oxide is deposited. Further, the polishing rate can be measured under the conditions of a polishing load of 4.0 psi, a polishing pad rotation speed of 150 rpm, while injecting calcined ceria slurry at 250 mL / min and rotating the platen at 150 rpm for 60 seconds. The temperature conditions during the measurement of the polishing rate are not particularly limited, and can be, for example, normal temperature conditions.

[0037] Also, the pad cut rate of the polishing layer can be 30 μm / hr to 60 μm / hr, 30 μm / hr to 50 μm / hr, 40 μm / hr to 60 μm / hr, or 40 μm / hr to 50 μm / hr.

[0038] The thickness of the polishing pad can be 0.8 mm to 5.0 mm, 1.0 mm to 4.0 mm, 1.0 mm to 3.0 mm, 1.5 mm to 2.5 mm, 1.7 mm to 2.3 mm, or 2.0 mm to 2.1 mm. Within this range, while minimizing the particle size deviation by the upper and lower parts of the pores, the basic physical properties as a polishing pad can be sufficiently exhibited.

[0039] [Polishing layer] The polishing layer provides a polishing surface that contacts the semiconductor substrate during the CMP process and constitutes the top pad in the polishing pad.

[0040] According to one implementation example, the polishing layer contains a polyurethane resin. The polishing layer contains a urethane prepolymer, a foaming agent, and a curing agent. Specifically, the polyurethane resin is obtained from a composition containing a urethane prepolymer, a foaming agent, and a curing agent.

[0041] More specifically, the polishing layer contains a polyurethane resin that is a reaction product of a urethane prepolymer, a foaming agent, and a curing agent, that is, a cured product of a composition in which the above components are mixed, thereby containing a porous polyurethane resin. Further, the polishing layer can contain a large number of pores formed from the foaming agent.

[0042] The thickness of the polishing layer is, for example, 0.8 mm or more, 1 mm or more, 1.2 mm or more, or 1.5 mm or more, and may also be 5 mm or less, 3 mm or less, 2.5 mm or less, or 2 mm or less. As a specific example, the thickness of the polishing layer may be 0.8 mm to 5 mm, or 1.5 mm to 3 mm.

[0043] The specific gravity of the polishing layer is, for example, 0.6 g / cm 3 or more, 0.7 g / cm 3 or more, or 0.75 g / cm 3 or more, and may also be 0.9 g / cm 3 or less, 0.85 g / cm 3 or less, or 0.8 g / cm 3 or less. As a specific example, the specific gravity of the polishing layer may be 0.6 g / cm 3 to 0.9 g / cm 3 or 0.7 g / cm 3 to 0.9 g / cm 3 and may be such.

[0044] The hardness of the polishing layer is, for example, 30 Shore D or more, 40 Shore D or more, or 50 Shore D or more, and may also be 80 Shore D or less, 70 Shore D or less, 65 Shore D or less, or 60 Shore D or less. As a specific example, the hardness of the polishing layer may be 30 Shore D to 80 Shore D, or 50 Shore D to 65 Shore D.

[0045] The tensile strength of the polishing layer is, for example, 5 N / mm 2 or more, 10 N / mm 2 or more, or 15 N / mm 2 or more, and may also be 30 N / mm 2 or less, 25 N / mm 2 or less, or 20 N / mm 2 or less. As a specific example, the tensile strength of the polishing layer may be 5 N / mm 2 to 30 N / mm 2 or 15 N / mm 2 to 25 N / mm 2 and may be such.

[0046] The elongation rate of the polishing layer is, for example, 50% or more, 70% or more, 90% or more, 106% or more, or 120% or more, and may also be 300% or less, 250% or less, 200% or less, or 150% or less. As a specific example, the elongation rate of the polishing layer may be 50% - 300% or 90% - 130%. The elongation rate may be the elongation at break.

[0047] As a specific example, the polishing layer may have a hardness of 50 Shore D - 65 Shore D, a tensile strength of 15 N / mm 2 ~25 N / mm 2 and an elongation rate of 90% - 130%.

[0048] The pores are dispersed and present in the polishing layer. The average diameter of the pores may be, for example, 10 μm - 60 μm, 10 μm - 50 μm, 20 μm - 50 μm, 20 μm - 40 μm, 10 μm - 30 μm, 20 μm - 25 μm, or 30 μm - 50 μm.

[0049] Also, the total area of the pores may be 30% - 60%, 35% - 50%, or 35% - 43% based on the total area of the polishing layer. Also, the total volume of the pores may be 30% - 70% or 40% - 60% based on the total volume of the polishing layer.

[0050] The polishing layer may have grooves on its surface for mechanical polishing. The grooves can have appropriate depths, widths, and intervals for mechanical polishing and are not particularly limited.

[0051] In one implementation example, by adjusting the chlorine content within a specific range, the physical properties and performance of the polishing pad can be maintained in an excellent state while reducing the size of debris, minimizing the occurrence of defects and scratches during the CMP process. For example, the chlorine (Cl) content analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard in the polishing layer can be less than 10,000 ppm. Specifically, the chlorine content within the polishing layer can be 5,000 ppm or less, 1,000 ppm or less, 500 ppm or less, 200 ppm or less, 100 ppm or less, 80 ppm or less, or 50 ppm or less.

[0052] Furthermore, the lower limit of the chlorine content range within the polishing layer according to the implementation example can be, for example, 0 ppm or more, more than 0 ppm, 1 ppm or more, 5 ppm or more, 10 ppm or more, 20 ppm or more, 50 ppm or more, or 100 ppm or more. Within the preferred range, debris will aggregate to an appropriate size, the surface area and adsorption force will be adjusted, adsorption and desorption on the wafer and pad will be facilitated, the electrical attraction / chuck force will be adjusted, and the polishing performance can become more appropriate.

[0053] As a specific example, the chlorine (Cl) content analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard in the polishing layer can be 10 ppm to 1,000 ppm. As another specific example, the chlorine (Cl) content analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard in the polishing layer can be 10 ppm to 100 ppm, 20 ppm to 80 ppm, or 20 ppm to 50 ppm. As yet another specific example, the chlorine (Cl) content analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard in the polishing layer can be 50 ppm to 10,000 or 100 ppm to 10,000 ppm.

[0054] The chlorine content can be obtained by measuring the chlorine content in the sample according to IEC62321-3-2, which is an international standard method for measuring the content of specific components by combustion ion chromatography (C-IC). At this time, the sample in which the chlorine content is measured can be a circular sample collected from the polishing layer of the polishing pad with a size of 3 cm in diameter and 0.3 cm in height. [Urethane prepolymer] The polishing layer of the polishing pad according to one implementation example contains a urethane prepolymer. Prepolymer means a polymer having a relatively low molecular weight in which the degree of polymerization is stopped at an intermediate stage so as to be easily molded in the production of a cured product. The prepolymer can be formed into a final cured product by itself or after reacting with other polymerizable compounds.

[0055] In one implementation example, the urethane prepolymer can be prepared by reacting an isocyanate compound with a polyol.

[0056] As the isocyanate compound used for preparing the urethane prepolymer, one selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and combinations thereof can be used.

[0057] The isocyanate compound can include, for example, one selected from the group consisting of toluene 2,4-diisocyanate (2,4-TDI), toluene 2,6-diisocyanate (2,6-TDI), naphthalene-1,5-diisocyanate, para-phenylene diisocyanate, tolidine diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and combinations thereof.

[0058] The polyol is a compound containing at least two or more hydroxy groups (-OH) per molecule, and may include, for example, one selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, and combinations thereof.

[0059] The polyol may include, for example, one selected from the group consisting of polytetramethylene ether glycol, polypropylene ether glycol, ethylene glycol, 1,2 - propylene glycol, 1,3 - propylene glycol, 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, dipropylene glycol, tripropylene glycol, and combinations thereof.

[0060] The polyol may have a weight - average molecular weight (Mw) of 100 to 3000. The polyol may have a weight - average molecular weight (Mw) of, for example, 100 to 3000, for example, 100 to 2000, for example, 100 to 1800.

[0061] In one embodiment, the polyol may include a low - molecular - weight polyol with a weight - average molecular weight (Mw) of 100 to 300 and a high - molecular - weight polyol with a weight - average molecular weight (Mw) of 300 to 1800.

[0062] The urethane prepolymer may have a weight - average molecular weight of 500 to 3000. The urethane prepolymer may have a weight - average molecular weight (Mw) of, for example, 1000 to 2000, for example, 1000 to 1500.

[0063] In one implementation example, the isocyanate compound for preparing the urethane prepolymer includes an aromatic diisocyanate compound, and the aromatic diisocyanate compound may include, for example, 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI). The polyol compound for preparing the urethane prepolymer may include polytetramethylene ether glycol (PTMEG) and diethylene glycol (DEG).

[0064] In another implementation example, the isocyanate compound for preparing the urethane prepolymer can include an aromatic diisocyanate compound and an alicyclic diisocyanate compound. For example, the aromatic diisocyanate compound includes 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI), and the alicyclic diisocyanate compound may include dicyclohexylmethane diisocyanate (H12MDI). The polyol compound for preparing the urethane prepolymer may include polytetramethylene ether glycol (PTMEG) and diethylene glycol (DEG).

[0065] The urethane prepolymer may have a terminal isocyanate group content (NCO%) of 5 wt% or more, 7.5 wt% or more, or 10 wt% or more, and may also be 13 wt% or less, 12 wt% or less, or 11 wt% or less. As a specific example, the urethane prepolymer may have a terminal isocyanate group content (NCO%) of 7.5 wt% to 12 wt%. As a more specific example, the urethane prepolymer may have a terminal isocyanate group content (NCO%) of 11 wt% to 12 wt%.

[0066] The terminal isocyanate group content (NCO%) of the urethane prepolymer can be designed by comprehensively adjusting the types and contents of the isocyanate compound and polyol compound for preparing the urethane prepolymer, the process conditions such as temperature, pressure, and time in the process of preparing the urethane prepolymer, and the types and contents of additives used in the preparation of the urethane prepolymer.

[0067] When the terminal isocyanate group content (NCO%) of the urethane prepolymer satisfies the above range, the reaction rate, reaction time, and final cured structure, etc. when subsequently reacting the urethane prepolymer with a curing agent can be adjusted in a direction advantageous to the polishing performance according to the use and purpose of the final polishing pad.

[0068] In one implementation example, the terminal isocyanate group content (NCO%) of the urethane prepolymer can be 8 wt% to 10 wt%, for example, 8 wt% to 9.4 wt%. When the NCO% is less than the above range, as the electrical properties due to the chemical cured structure in the polishing pad, the desired polishing performance may not be realized in terms of polishing rate and flatness, and there may be a problem that the life of the polishing pad is reduced due to an excessive increase in the cutting rate, etc. On the other hand, when the NCO% exceeds the above range, surface defects such as scratches and chatter marks on the semiconductor substrate may increase.

[0069] [Blowing agent] The blowing agent may include one selected from the group consisting of a solid-phase blowing agent, a gas-phase blowing agent, a liquid-phase blowing agent, and combinations thereof as a component for forming the pore structure in the polishing layer.

[0070] According to one implementation example, the foaming agent is a non-chlorine-based foaming agent that does not contain a chlorine component. In particular, it does not contain a chlorine-based foaming agent component commonly used in the production of polishing pads, such as vinylidene chloride (VDC), or the use thereof can be minimized. For example, the content of the non-chlorine-based foaming agent based on the total weight of the foaming agent is 50% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, 97% by weight or more, 99% by weight or more, or 99.5% by weight or more, and is also 100% by weight or less or 99.5% by weight or less. As specific examples, it can be 80% by weight to 100% by weight, 90% by weight to 100% by weight, or 80% by weight to 99.5% by weight. Also, the content of the chlorine-based foaming agent based on the total weight of the foaming agent is 20% by weight or less, 10% by weight or less, 5% by weight or less, 1% by weight or less, 0.5% by weight or less, or 0.3% by weight or less, and is also 0% by weight or more, 0.1% by weight or more, 0.5% by weight or more. As specific examples, it can be 0% by weight to 20% by weight, 0% by weight to 1% by weight, 0% by weight to 0.5% by weight, or 0.5% by weight to 20% by weight.

[0071] The foaming agent can be one or more selected from a solid-phase foaming agent containing particles with a hollow structure, a liquid-phase foaming agent using a volatile liquid, and an inert gas.

[0072] As an example, the solid-phase foaming agent can contain particles with a hollow structure whose size is adjusted by expansion due to heat. Such a solid-phase foaming agent has the advantage that it can be uniformly adjusted in the pore size by being put into the raw material in an already expanded form and having a uniform particle size.

[0073] Also, the solid-phase foaming agent can contain expandable particles. The expandable particles are particles having the property of being expandable by heat or pressure, etc., and the size in the final polishing layer can be determined by the heat or pressure, etc., applied during the process of manufacturing the polishing layer. The expandable particles are put into the raw material in a non-expanded particle state and are expanded by the heat or pressure applied during the manufacturing process of the polishing layer, and the final size can be determined.

[0074] The average particle size of the solid foaming agent is, for example, 5 μm to 100 μm, and specifically may be 5 μm to 50 μm or 20 μm to 50 μm. The average particle size of the solid foaming agent means the average particle size of the expanded particles themselves when the solid foaming agent is particles introduced into the raw material in an expanded state as described later, and when the solid foaming agent is particles introduced into the raw material in an unexpanded state as described later, it may mean the average particle size of the particles after expansion by heat or pressure during the manufacturing process.

[0075] The expandable particle type solid foaming agent may include an outer skin of a resin material and an expansion-inducing component present inside the outer skin. Such expandable particles can be formed into a hollow structure by vaporization of the internal expansion-inducing component by heat during the manufacturing process.

[0076] For example, the outer skin may include a thermoplastic resin. The thermoplastic resin may be one or more selected from the group consisting of acrylonitrile-based copolymers, methacrylonitrile-based copolymers, and acrylic-based copolymers.

[0077] The thickness of the outer skin is, for example, 0.1 μm or more, 0.5 μm or more, 1 μm or more, 2 μm or more, or 3 μm or more, and is also 15 μm or less, 12 μm or less, or 10 μm or less, and may specifically be 2 μm to 15 μm as an example.

[0078] The expansion-inducing component may include one selected from the group consisting of hydrocarbon compounds, tetraalkylsilane compounds, and combinations thereof. Specifically, the hydrocarbon compound may include one selected from the group consisting of ethane, ethylene, propane, propene, n-butane, isobutene, n-butene, isobutene, n-pentane, isopentane, neopentane, n-hexane, heptane, petroleum ether, and combinations thereof. The tetraalkylsilane compound may include one selected from the group consisting of tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, trimethyl-n-propylsilane, and combinations thereof.

[0079] The solid foaming agent may include particles treated with an inorganic component. In one implementation example, the solid foaming agent may be one whose surface is treated with silica (SiO 2 ) particles. The treatment of the inorganic component of the solid foaming agent may prevent aggregation between multiple particles. The solid foaming agent treated with the inorganic component may have different chemical, electrical, and / or physical properties on the surface of the foaming agent from those of the solid foaming agent not treated with the inorganic component.

[0080] Commercially available products of the solid foaming agent include 920DE20d70, 051DET40d25, 051DET40d42, etc. of Nouryon, and F-65DE, F-80DE, FN-80SDE, etc. of Matsumoto.

[0081] As a specific example, the foaming agent used in the polishing pad according to the implementation example includes a solid foaming agent, and the solid foaming agent may include one or more selected from the group consisting of acrylonitrile-based copolymers, methyl methacrylate-based copolymers, methacrylonitrile-based copolymers, and acrylic-based copolymers.

[0082] Based on 100 parts by weight of the urethane prepolymer, the content of the solid foaming agent is 0.1 part by weight or more, 0.5 part by weight or more, or 1 part by weight or more, and can be 5 parts by weight or less, 3 parts by weight or less, or 2 parts by weight or less. As a specific example, based on 100 parts by weight of the urethane prepolymer, the content of the solid foaming agent can be 0.1 part by weight to 5 parts by weight, or 0.5 part by weight to 2 parts by weight.

[0083] According to the intended pore structure and physical properties of the polishing layer, the type and content of the solid foaming agent can be designed.

[0084] On the other hand, the liquid foaming agent can be introduced during the process of mixing and reacting the prepolymer and the curing agent to form pores and does not participate in the reaction between the prepolymer and the curing agent. Also, the liquid foaming agent physically vaporizes due to the heat generated during the process of mixing and reacting the prepolymer and the curing agent to form pores.

[0085] The volatile liquid foaming agent does not react with isocyanate groups, amide groups, and alcohol groups and can be in a liquid phase at 25°C. Specifically, the volatile liquid foaming agent can be selected from the group consisting of perfluorinated compounds such as cyclopentane, n-pentane, cyclohexane, n-butyl acetate, bis(nonafluorobutyl)(trifluoromethyl)amine, and perfluorotributylamine, perfluoro-N-methylmorpholine, perfluorotripentylamine, perfluorohexane. Commercially available products of the perfluorinated compounds include FC-40, FC-43, FC-70, FC-72, FC-770, FC-3283, FC-3284 from 3M.

[0086] In addition, the blowing agent may include a gas-phase blowing agent. For example, the blowing agent may include a solid-phase blowing agent and a gas-phase blowing agent.

[0087] The gas-phase blowing agent may include an inert gas. The gas-phase blowing agent is introduced during the reaction process of the urethane prepolymer and the curing agent and can be used as a pore-forming element.

[0088] The type of the inert gas is not particularly limited as long as it is a gas that does not participate in the reaction between the urethane prepolymer and the curing agent. For example, the inert gas may include one selected from the group consisting of nitrogen gas (N 2 ), carbon dioxide gas (CO 2 ), argon gas (Ar), helium gas (He), and combinations thereof.

[0089] According to the intended pore structure and physical properties of the polishing layer, the type and content of the gas-phase blowing agent can be designed.

[0090] The inert gas can be introduced in a volume corresponding to 10% - 30% of the total volume of the composition. Specifically, the inert gas can be introduced in a volume corresponding to 15% - 30% of the total volume of the composition. Specifically, the gas-phase blowing agent can be injected through a predetermined injection line during the mixing process of the urethane prepolymer, the solid-phase blowing agent, and the curing agent. The injection rate of the gas-phase blowing agent can be about 0.8 L / min to about 2.0 L / min, for example, about 0.8 L / min to about 1.8 L / min, for example, about 0.8 L / min to about 1.7 L / min, for example, about 1.0 L / min to about 2.0 L / min, for example, about 1.0 L / min to about 1.8 L / min, for example, about 1.0 L / min to about 1.7 L / min.

[0091] [Curing Agent] The hardener is a compound for chemically reacting with the urethane prepolymer to form a final cured structure in the polishing layer, and may include, for example, an amine compound or an alcohol compound. Specifically, the hardener may include one selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, aliphatic alcohols, and combinations thereof.

[0092] According to one implementation example, the hardener may include a non-chlorine-based hardener that does not contain a chlorine component. For example, the content of the non-chlorine-based hardener based on the total weight of the hardener is 50% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, 97% by weight or more, 99% by weight or more, or 99.5% by weight or more, and is also 100% by weight or less or 99.5% by weight or less. As a specific example, it may be 80% by weight to 100% by weight, 90% by weight to 100% by weight, or 80% by weight to 99.5% by weight. Also, the content of the chlorine-based hardener based on the total weight of the hardener is 20% by weight or less, 10% by weight or less, 5% by weight or less, 1% by weight or less, or 0.5% by weight or less, 0.3% by weight or less, and is also 0% by weight or more, 0.1% by weight or more, 0.5% by weight or more. As a specific example, it may be 0% by weight to 20% by weight, 0% by weight to 1% by weight, 0% by weight to 0.5% by weight, or 0.5% by weight to 20% by weight.

[0093] The hardener may be at least one selected from a solid-phase hardener and a liquid-phase hardener.

[0094] The solid-phase hardener may contain an active hydrogen group. The solid-phase hardener may include an amine group (-NH 2 ) as the active hydrogen group.

[0095] Also, the solid-phase hardener may be an ester compound having two or more benzene rings. Specifically, the solid-phase hardener may contain two or more of the ester groups in the molecule.

[0096] The solid-phase curing agent may have a weight-average molecular weight of 150 to 400, such as 150 to 350, such as 200 to 350, such as 250 to 350, such as 300 to 350. The solid-phase curing agent may have a melting point (m.p) of 100°C to 150°C, such as 100°C to 140°C, such as 110°C to 130°C.

[0097] In one implementation example, the solid-phase curing agent may include one or more selected from the group consisting of 1,3-propanediol bis(4-aminobenzoate) (PDPAB), 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylene bis-methyl anthranilate (MBNA).

[0098] The liquid-phase curing agent may contain an active hydrogen group. As the active hydrogen group, the liquid-phase curing agent may include one or more selected from the group consisting of an amine group (-NH 2 ), a hydroxyl group (-OH), a carboxylic acid group (-COOH), an epoxy group, and combinations thereof. Specifically, it may include an amine group (-NH 2 ) group.

[0099] In addition, the liquid-phase curing agent may contain sulfur in the molecule, specifically, it may contain two or more sulfur elements in the molecule.

[0100] The liquid-phase curing agent may have a weight-average molecular weight of 50 to 300, such as 100 to 250, such as 150 to 250, such as 200 to 250.

[0101] In addition, the liquid-phase curing agent may be in a liquid phase at room temperature. Or, the liquid-phase curing agent may have a boiling point (b.p) of 160°C to 240°C, specifically 170°C to 240°C, more specifically 170°C to 220°C.

[0102] Examples of the liquid hardener may include one or more selected from the group consisting of 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, and N,N'-bis(sec-butylamino)diphenylmethane.

[0103] In addition to the liquid hardener and the solid hardener, the hardener may further contain other hardeners. The other hardeners may be, for example, one or more of an amine compound and an alcohol compound. Specifically, the other hardeners may include one or more compounds selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, and aliphatic alcohols.

[0104] For example, the other hardeners may be one or more selected from the group consisting of diaminodiphenyl methane, diaminodiphenyl sulphone, m-xylylene diamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, ethylene glycol, diethyleneglycol, dipropyleneglycol, butanediol, hexanediol, glycerine, and trimethylolpropane.

[0105] As a specific example, the curing agent may include one or more selected from the group consisting of diethyltoluenediamine (DETDA), 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 1,3-propanediol bis(4-aminobenzoate) (PDPAB), N,N'-bis(sec-butylamino)diphenylmethane, 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylene bis-methyl anthranilate (MBNA).

[0106] The content of the curing agent is 5 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, or 20 parts by weight or more based on 100 parts by weight of the urethane prepolymer, and may be 50 parts by weight or less, 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, 30 parts by weight or less, or 25 parts by weight or less. Specifically, the content of the curing agent is 10 to 40 parts by weight based on 100 parts by weight of the urethane prepolymer, and more specifically, may be 15 to 35 parts by weight or 15 to 25 parts by weight.

[0107] [Additives] The composition for producing the polishing layer may further include other additives such as a surfactant and a reaction rate regulator. The names such as "surfactant" and "reaction rate regulator" are arbitrary names based on the main roles of the corresponding substances, and each corresponding substance does not necessarily perform only the functions limited by the names.

[0108] The surfactant is not particularly limited as long as it plays a role in preventing phenomena such as aggregation or overlap of pores. For example, the surfactant may include a silicone-based surfactant.

[0109] The surfactant can be used in a content of 0.2 parts by weight to 2 parts by weight based on 100 parts by weight of the urethane prepolymer. Specifically, the surfactant can be contained in a content of 0.2 parts by weight to 1.9 parts by weight, for example, 0.2 parts by weight to 1.8 parts by weight, for example, 0.2 parts by weight to 1.7 parts by weight, for example, 0.2 parts by weight to 1.6 parts by weight, for example, 0.2 parts by weight to 1.5 parts by weight, for example, 0.5 parts by weight to 1.5 parts by weight based on 100 parts by weight of the urethane prepolymer. When the surfactant is included in the content within the above range, pores derived from the gas-phase foaming agent can be stably formed and maintained in the mold.

[0110] The reaction rate regulator serves to promote or delay the reaction, and a reaction accelerator, a reaction retarder, or both can be used according to the purpose. The reaction rate regulator may include a reaction accelerator. For example, the reaction accelerator may be one or more reaction accelerators selected from the group consisting of tertiary amine compounds and organometallic compounds.

[0111] Specifically, the reaction rate regulator may include one or more selected from the group consisting of triethylenediamine, dimethylethanolamine, tetramethylbutanediamine, 2-methyl-triethylenediamine, dimethylcyclohexylamine, triethylamine, triisopropanolamine, 1,4-diazabicyclo(2,2,2)octane, bis(2-methylaminoethyl)ether, trimethylaminoethylethanolamine, N,N,N',N'',N''-pentamethyldiethylenetriamine, dimethylaminoethylamine, dimethylaminopropylamine, benzyldimethylamine, N-ethylmorpholine, N,N-dimethylaminoethylmorpholine, N,N-dimethylcyclohexylamine, 2-methyl-2-azanorborene, dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin maleate, dibutyltin di-2-ethylhexanoate, and dibutyltin dimercaptide. Specifically, the reaction rate regulator may include one or more selected from the group consisting of benzyldimethylamine, N,N-dimethylcyclohexylamine, and triethylamine.

[0112] The reaction rate regulator can be used in an amount of 0.05 parts by weight to 2 parts by weight based on 100 parts by weight of the urethane prepolymer. Specifically, the reaction rate regulator can be used in an amount of 0.05 parts by weight to 1.8 parts by weight, for example, 0.05 parts by weight to 1.7 parts by weight, for example, 0.05 parts by weight to 1.6 parts by weight, for example, 0.1 parts by weight to 1.5 parts by weight, for example, 0.1 parts by weight to 0.3 parts by weight, for example, 0.2 parts by weight to 1.8 parts by weight, for example, 0.2 parts by weight to 1.7 parts by weight, for example, 0.2 parts by weight to 1.6 parts by weight, for example 0.2 parts by weight to 1.5 parts by weight, for example 0.5 parts by weight to 1 part by weight based on 100 parts by weight of the urethane prepolymer. When the reaction rate regulator is used within the above content range, the curing reaction rate of the prepolymer composition can be appropriately adjusted to form a polishing layer having pores and hardness of a desired size.

[0113] [Other constituent layers] The support layer constitutes a lower pad and serves to absorb and disperse an external impact applied to the polishing layer while supporting the polishing layer, thereby minimizing the occurrence of damage and defects to the object to be polished during the polishing process using the polishing pad.

[0114] The support layer may include, but is not limited to, a non-woven fabric or suede. In one implementation example, the support layer may be a resin-impregnated non-woven fabric. The non-woven fabric may be a fiber non-woven fabric including one selected from the group consisting of polyester fibers, polyamide fibers, polypropylene fibers, polyethylene fibers, and combinations thereof. The resin impregnated in the non-woven fabric may include one selected from the group consisting of polyurethane resins, polybutadiene resins, styrene-butadiene copolymer resins, styrene-butadiene-styrene copolymer resins, acrylonitrile-butadiene copolymer resins, styrene-ethylene-butadiene-styrene copolymer resins, silicone rubber resins, polyester-based elastomer resins, polyamide-based elastomer resins, and combinations thereof.

[0115] The thickness of the support layer may be, for example, 0.3 mm or more, or 0.5 mm or more, and may also be 3 mm or less, 2 mm or less, or 1 mm or less. As a specific example, the thickness of the support layer may be 0.3 mm to 3 mm or 0.5 mm to 1 mm.

[0116] The hardness of the support layer may be, for example, 50 Asker C or more, 60 Asker C or more, or 70 Asker C or more, and may also be 100 Asker C or less, 90 Asker C or less, or 80 Asker C or less. As a specific example, the hardness of the support layer may be 50 Asker C to 100 Asker C or 60 Asker C to 90 Asker C.

[0117] Also, an adhesive layer may be inserted between the polishing layer (upper pad) and the support layer (lower pad).

[0118] The adhesive layer may contain a hot melt adhesive. The hot melt adhesive may be one or more selected from the group consisting of polyurethane-based resins, polyester-based resins, ethylene-vinyl acetate-based resins, polyamide-based resins, and polyolefin-based resins. Specifically, the hot melt adhesive may be one or more selected from the group consisting of polyurethane-based resins and polyester-based resins.

[0119] Also, a double-sided tape is attached to the lower part of the support layer, and when applied to a CMP apparatus, the release paper of the double-sided tape can be removed and attached to the platen for use.

[0120] [Manufacturing Method of Polishing Pad] A manufacturing method of a polishing pad according to one implementation example includes the steps of preparing a polishing layer composition containing a urethane prepolymer, a foaming agent, and a curing agent, injecting the polishing layer composition into a mold and curing it to manufacture a polishing layer, and bonding the polishing layer to a support layer.

[0121] The specific types and contents of the urethane prepolymer, curing agent, and foaming agent are as exemplified above.

[0122] The polishing layer composition can be prepared by sequentially or simultaneously mixing a urethane prepolymer, a foaming agent, and a curing agent.

[0123] As an example, the step of preparing the polishing layer composition may be performed by further mixing the foaming agent after mixing the urethane prepolymer with the curing agent, or by further mixing the curing agent after mixing the urethane prepolymer with the foaming agent.

[0124] As another example, the urethane prepolymer, the curing agent, and the foaming agent are substantially simultaneously introduced into the mixing process, and when a foaming agent, a surfactant, and an inert gas are further added, they may also be substantially simultaneously introduced into the mixing process.

[0125] As still another example, the urethane prepolymer, the foaming agent, and the surfactant may be premixed and then the curing agent may be added, or the curing agent and the inert gas may be added together.

[0126] In the mixing, the urethane prepolymer and the curing agent are mixed to initiate the reaction, and the foaming agent and the inert gas can be uniformly dispersed in the raw material. At this time, the reaction rate regulator can intervene in the reaction between the urethane prepolymer and the curing agent from the initial stage of the reaction to adjust the reaction rate. Specifically, the mixing can be performed at a speed of 1000 rpm to 10000 rpm or 4000 rpm to 7000 rpm. When within the speed range, it may be more advantageous for the inert gas and the foaming agent to be uniformly dispersed in the raw material.

[0127] Also, the step of preparing the polishing layer composition is performed under the conditions of 50°C to 150°C and can be performed under vacuum degassing conditions as necessary.

[0128] When the foaming agent includes a solid-phase foaming agent, the step of preparing the polishing layer composition may include a step of mixing the urethane prepolymer and the solid-phase foaming agent to prepare a first preliminary composition, and a step of mixing the first preliminary composition and the curing agent to prepare a second preliminary composition.

[0129] The viscosity of the first preliminary composition is about 1000 cps to about 2000 cps at about 80°C, and can be, for example, about 1000 cps to about 1800 cps, for example, about 1000 cps to about 1600 cps, for example, about 1000 cps to about 1500 cps.

[0130] When the foaming agent includes a gas-phase foaming agent, the step of preparing the polishing layer composition may include a step of preparing a third preliminary composition including the urethane prepolymer and the curing agent, and a step of injecting the gas-phase foaming agent into the third preliminary composition to prepare a fourth preliminary composition. In one implementation example, the third preliminary composition may further include a solid-phase foaming agent.

[0131] In one implementation example, the step of manufacturing the polishing layer may include a step of preparing a mold preheated to a first temperature, a step of injecting the polishing layer composition into the preheated mold and curing it, and a step of post-curing the cured polishing layer composition under a second temperature condition higher than the preheating temperature.

[0132] In one implementation example, the temperature difference between the first temperature and the second temperature is about 10°C to about 40°C, and can be, for example, about 10°C to about 35°C, for example, about 15°C to about 35°C. In one implementation example, the first temperature can be about 60°C to about 100°C, for example, about 65°C to about 95°C, for example, about 70°C to about 90°C. In one implementation example, the second temperature is about 100°C to about 130°C, and can be, for example, about 100°C to about 125°C, for example, about 100°C to about 120°C.

[0133] The step of curing the polishing layer composition at the first temperature may 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.

[0134] The step of post-curing the polishing layer composition cured at the first temperature at the second temperature can be carried out 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.

[0135] Subsequently, the step of injecting the polishing layer composition into a mold and then curing it can be carried out under temperature conditions of 60°C to 120°C and pressure conditions of 50 kg / m 2 ~200 kg / m 2 .

[0136] In addition, the manufacturing method may further include a step of cutting the surface of the obtained polishing layer, a step of processing grooves on the surface, an adhesion step with the lower layer part, an inspection step, a packaging step, and the like. These steps can be carried out by a normal polishing pad manufacturing method.

[0137] As an example, the manufacturing method of the polishing pad may include a step of processing at least one surface of the polishing layer. The step of processing at least one surface of the polishing layer may include at least one of a step of forming grooves on at least one surface of the polishing layer, a step of turning at least one surface of the polishing layer, and a step of roughening at least one surface of the polishing layer.

[0138] The grooves may include at least one of concentric grooves formed at a predetermined interval from the center of the polishing layer and radial grooves continuously connected from the center of the polishing layer to the edge of the polishing layer. The turning can be carried out by a method of shaving off a predetermined thickness of the polishing layer using a cutting tool. The roughening can be carried out by a method of processing the surface of the polishing layer with a sanding roller.

[0139] [Pyrolysis oil] In addition, pyrolysis oil obtained from the polishing layer of the polishing pad is provided. According to one implementation example, the pyrolysis oil is obtained from the polishing layer of the aforementioned polishing pad.

[0140] The chlorine content analyzed by combustion ion chromatography (C-IC) based on the IEC62321-3-2 standard of the pyrolysis oil is less than 10,000 ppm, and can be, for example, 5,000 ppm or less, 1,000 ppm or less, 500 ppm or less, 200 ppm or less, 100 ppm or less, 80 ppm or less, or 50 ppm or less. When the content of the residual chlorine component contained in the pyrolysis oil obtained by pyrolyzing the polishing layer of the polishing pad is within the preferred range, environmental problems caused by the chlorine component can be effectively reduced.

[0141] Furthermore, the lower limit of the chlorine content range in the pyrolysis oil obtained from the polishing layer of the polishing pad according to the above-mentioned examples can be, for example, 0 ppm or more, more than 0 ppm, 1 ppm or more, 2 ppm or more, 3 ppm or more, 4 ppm or more, or 5 ppm or more. When the content of the residual chlorine component contained in the pyrolysis oil is within the above range, the pyrolysis oil can be converted into a high-quality energy source.

[0142] In addition, the composition and properties of the pyrolysis oil are as exemplified in the above description of the polishing pad.

[0143] The temperature for pyrolyzing the polishing layer to obtain such pyrolysis oil is, for example, 280°C to 350°C, and specifically can be 280°C to 345°C, 290°C to 340°C, 295°C to 330°C, 300°C to 325°C, or 310°C to 320°C. Also, the time for pyrolyzing the polishing layer to obtain the pyrolysis oil is, for example, 1 hour to 10 hours, and specifically can be 2 hours to 9 hours, 3 hours to 9 hours, 4 hours to 8 hours, 5 hours to 7 hours, 5 hours to 6 hours, or 6 hours to 7 hours. As a specific example, the pyrolysis oil can be obtained by pyrolyzing the polishing layer at 280°C to 350°C for 3 hours to 9 hours.

[0144] On the other hand, when the pyrolysis of the polishing layer is completed, residual solids will remain, which can be used as solid fuel.

[0145] Such pyrolysis oil is obtained from the polishing layer of the aforementioned polishing pad. At this time, the polishing pad can be a waste polishing pad that has been used in the CMP process. Thereby, the realization example can improve the conventional problem that it was difficult to recycle waste polishing pads, and furthermore, it can contribute to the provision of renewable energy and the reduction of environmental problems.

[0146] The pyrolysis oil is obtained by pyrolyzing the polishing layer of the polishing pad. FIG. 2 shows the process of obtaining pyrolysis oil by pyrolyzing the polishing layer of the polishing pad. Referring to FIG. 2, the method for producing the pyrolysis oil includes a step of charging the polishing layer 10 of the polishing pad into the chamber 100 (step S-1), a step of pyrolyzing the polishing layer 10 charged into the chamber 100 at 280° C. to 350° C. (step S-2), and a step of passing the vaporization stream formed by the pyrolysis through the heat exchanger 200 to obtain a liquid pyrolysis oil (step S-3).

[0147] The step S-1 may consist of a process of charging the polishing layer, specifically the polishing layer of the waste polishing pad, into the chamber. That is, the polishing layer of the waste polishing pad that has been used up in the CMP process can be charged into the chamber. When the waste polishing pad further includes a support layer and an adhesive layer in addition to the polishing layer (in a state where the polishing layer / adhesive layer / support layer are bonded), after separating each layer, only the polishing layer can be charged into the chamber. Also, one or more, specifically 1 to 5, or 2 to 3 polishing layers can be charged into the chamber at the same time. Thereby, the realization example can easily recycle (process) the waste polishing pad.

[0148] The chamber is attached to a reactor capable of performing pyrolysis of the polishing layer, is made of a heat-resistant material, and may have a structure that separates from the reactor when pyrolysis is completed.

[0149] The S-2 stage may consist of a process of thermally decomposing the polishing layer introduced into the chamber at 280°C to 350°C. Specifically, the thermal decomposition temperature of the polishing layer may be 280°C to 345°C, 290°C to 340°C, 295°C to 330°C, 300°C to 325°C, or 310°C to 320°C. By thermally decomposing the polishing layer within this temperature range, pyrolysis oil can be obtained in a high yield, and the generation of harmful components such as dioxins during the thermal decomposition process can be minimized. Also, it can be controlled so that the pyrolysis oil contains chlorine components at a required level.

[0150] On the other hand, the thermal decomposition of the polishing layer can be carried out in the presence of a catalyst. The catalyst is not particularly limited as long as it is a commonly known catalyst used in the thermal decomposition process of polymers, and specifically, it may contain zeolite or potassium hydroxide. By carrying out the thermal decomposition in the presence of the catalyst, while increasing the yield of pyrolysis oil, the generation of by-products such as tar can be suppressed.

[0151] As such an S-2 stage proceeds, the pyrolysis oil can be vaporized and converted into a vapor stream.

[0152] The S-3 stage may consist of a process of passing the vapor stream formed by the thermal decomposition through a heat exchanger to obtain liquid pyrolysis oil. Specifically, the vapor stream can be converted into liquid pyrolysis oil by being cooled through the heat exchanger. The heat exchanger is not particularly limited as long as it has a commonly known structure and material.

[0153] On the other hand, after the completion of the S-3 stage, the solid matter remaining in the chamber can be used as solid fuel through a separate recovery process. Also, the pyrolysis oil obtained through the S-3 stage may undergo a purification process such as distillation.

[0154] The pyrolysis oil can be converted into a high-quality energy source by adjusting the content of the residual chlorine component contained therein to a specific range.

[0155] Figure 3 shows the process of obtaining an energy source and basic raw materials from pyrolysis oil. Referring to Figure 3, the pyrolysis oil obtained by pyrolyzing the polishing layer is converted, for example, into heavy oil, naphtha, etc. through a purification process in a distillation column 300. At this time, the heavy oil can be used as an energy source such as heating oil and power plant fuel. In addition, the naphtha is converted into petrochemical basic raw materials such as benzene, toluene, xylene, and butanediol through processes such as a cracking process and can be used in the industry.

[0156] (Example) Examples are described below, but the realizable scope is not limited to these.

[0157] (Example 1) Step (1) Preparation of urethane prepolymer 2,4-Toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), dicyclohexylmethane diisocyanate (H12MDI), polytetramethylene ether glycol (PTMEG), and diethylene glycol (DEG) were charged into a four-necked flask and reacted at 80 °C for 3 hours to prepare a urethane prepolymer with a terminal NCO group content (NCO%) of 10 wt%.

[0158] Step (2) Manufacture of the polishing layer A casting device equipped with tanks and input lines for supplying raw materials such as prepolymer, curing agent, inert gas, and blowing agent was prepared. The urethane prepolymer prepared above, curing agent (DMTDA, Covestro), solid blowing agent (F-65DE, Matsumoto), inert gas (N 2 )), and silicone surfactant (Evonik) were filled into their respective tanks. Specifically, 32 parts by weight of the curing agent, 1 part by weight of the solid blowing agent, and 1 part by weight of the surfactant were filled per 100 parts by weight of the prepolymer, and the inert gas was introduced at 1.5 L / min.

[0159] The raw materials were stirred while being fed into the mixing head at a constant speed through each feed line. The rotational speed of the mixing head was set at approximately 5000 rpm. After the mixed composition of the raw materials was mixed in the mixing head, it was poured into a mold measuring 1000 mm in length, 1000 mm in width, and 3 mm in height. The temperature of the mold was adjusted to approximately 80 (±5) °C. The mixed composition solidified in the mold and was cast into a sheet form. The sheet was post-cured at approximately 110 (±5) °C for about 18 hours to produce a polishing layer.

[0160] Step (3) Production of the polishing pad One surface of the polishing layer was turned using a cutting tool and subjected to a process of forming grooves using chips to produce an average thickness of 2 mm. A cushion layer impregnated with a polyurethane resin was provided on a polyester fiber non-woven fabric, and a heat-fusible adhesive was applied to one surface of the cushion layer and the back surface of the groove-forming surface of the polishing layer, respectively. The cushion layer and the polishing layer were laminated such that the surfaces coated with the respective heat-fusible adhesives were in contact with each other, and pressure lamination was performed under the pressure conditions of a temperature of approximately 140 (±5) °C and 2 kgf / cm 2 to produce a polishing pad.

[0161] (Example 2) The same procedure as in Example 1 was repeated, but in step (2), a casting apparatus equipped with tanks and feed lines for supplying raw materials such as prepolymer, curing agent, inert gas, and foaming agent was prepared. The urethane prepolymer, curing agent (DMTDA, Covestro), solid-phase foaming agent (051DET40d25, Nouryon), inert gas (N 2 ), and silicone surfactant (Evonik) prepared above were filled into their respective tanks, and the subsequent procedure was carried out in the same manner as in Example 1 to produce a polishing pad.

[0162] (Example 3) Repeat the same procedure as in Example 1. However, in step (2), prepare a casting apparatus equipped with tanks and input lines for supplying raw materials such as prepolymer, curing agent, inert gas, and foaming agent respectively. The urethane prepolymer, curing agent (DMTDA, Covestro), solid foaming agent (F-80DE, Matsumoto), inert gas (N 2 ), and silicone surfactant (Evonik) prepared above were filled into their respective tanks, and the subsequent procedure was carried out in the same manner as in Example 1 to produce a polishing pad.

[0163] (Comparative Example 1) Repeat the same procedure as in Example 1. However, in step (2), prepare a casting apparatus equipped with tanks and input lines for supplying raw materials such as prepolymer, curing agent, inert gas, and foaming agent respectively. The urethane prepolymer, curing agent (MOCA, Ishihara), solid foaming agent (051DET40d25, Nouryon), inert gas (N 2 ), and silicone surfactant (Evonik) prepared above were filled into their respective tanks, and the subsequent procedure was carried out in the same manner as in Example 1 to produce a polishing pad.

[0164] (Comparative Example 2) Repeat the same procedure as in Example 1. However, in step (2), prepare a casting apparatus equipped with tanks and input lines for supplying raw materials such as prepolymer, curing agent, inert gas, and foaming agent respectively. The urethane prepolymer, curing agent (MOCA, Ishihara), solid foaming agent (461DET40d25, Nouryon), inert gas (N 2 ), and silicone surfactant (Evonik) prepared above were filled into their respective tanks, and the subsequent procedure was carried out in the same manner as in Example 1 to produce a polishing pad.

[0165] (Test Example 1) The polishing layer, support layer, and polishing pad obtained by laminating them manufactured above were tested as follows.

[0166] (1) Hardness The sample was cut into pieces of 5 cm × 5 cm (thickness: 2 mm), stored at normal temperature, 30 °C, 50 °C, and 70 °C for 12 hours respectively, and then the Shore D hardness and Asker C hardness were measured using a hardness tester.

[0167] (2) Specific gravity The sample was cut into pieces of 2 cm × 5 cm (thickness: 2 mm), stored at a temperature of 25 °C for 12 hours, and then the multi-layer specific gravity was measured using a specific gravity meter.

[0168] (3) Tensile strength The sample was cut into pieces of 4 cm × 1 cm (thickness: 2 mm), and using a universal testing machine (UTM), the maximum strength value just before the break of the polishing pad was measured at a speed of 50 mm / min.

[0169] (4) Elongation at break The sample was cut into pieces of 4 cm × 1 cm (thickness: 2 mm), and using a universal testing machine (UTM), the maximum deformation amount just before the break of the polishing pad was measured at a speed of 50 mm / min. Then, the ratio of the maximum deformation amount to the initial length was expressed as a percentage (%). The results were summarized in the following table.

[0170]

Table 1

[0171] As can be seen from the above table, the polishing pads of Examples 1 to 3 were at a level equal to or higher than those of the polishing pads of Comparative Examples 1 and 2 in terms of hardness, specific gravity, tensile strength, and elongation at break.

[0172] (Test Example 2: Component analysis) The polishing layers of the polishing pads manufactured in the examples and comparative examples, and the pyrolysis oil obtained therefrom were analyzed as follows.

[0173] (1) Chlorine content (polishing pad) A circular sample with a size of 3 cm in diameter and 0.3 cm in height was prepared from the polishing layer of the polishing pad. Based on IEC62321-3-2, an international standard method for measuring the content of specific components by combustion ion chromatography (C-IC), the chlorine content in the polishing layer was measured.

[0174] (2) Chlorine content (pyrolysis oil) The polishing layer of the polishing pad was separated and put into the chamber, and a temperature of 320 °C was applied for 6 hours to pyrolyze the polishing layer. The vaporization stream formed by the pyrolysis was passed through a heat exchanger to obtain liquid pyrolysis oil. Then, after the process of cooling when the liquid pyrolysis oil stream disappeared, the production of pyrolysis oil was completed. The produced pyrolysis oil was put into a sample container, and based on IEC62321-3-2, an international standard method for measuring the content of specific components by combustion ion chromatography (C-IC), the chlorine content in the pyrolysis oil was measured.

[0175] (3) Elemental analysis The elements in the pyrolysis oil of the polishing layer obtained by the same method as in (2) above were analyzed. Using a FLASH 2000 CHNS / O analyzer (Elemental Analyzer, Thermo Fisher Scientific), the elemental contents of C, H, N, S, and O excluding the halogen group (F, Cl) were burned and reduced at 1800 °C. The generated gas was quantitatively analyzed for the content of sulfur (S) element by a GC column.

[0176] (4) Inorganic content analysis - ICP-OES The inorganic content in the pyrolysis oil of the polishing layer obtained by the same method as in (2) above was measured. The pyrolysis oil sample was put into an ICP-OES (5110SVDV, Agilent) and excited to an atomic or ionic excited state using an argon plasma. At this time, the intensity of the light emitted when the electrons of the atom or ion returned to the ground state or a lower state was measured. Then, based on the calibration graph, the inorganic content (Al, Si, Fe) in the pyrolysis oil was quantitatively analyzed.

[0177]

Table 2

[0178] As can be seen from the above table, the polishing layers of the polishing pads in Examples 1 to 3 and their pyrolysis oils were measured with the chlorine (Cl) content within a preferable range. Further, the pyrolysis oils obtained from the polishing layers of the polishing pads in Examples 1 to 3 were also measured with the content of components such as sulfur (S), aluminum (Al), iron (Fe), and silicon (Si) all within preferable ranges.

[0179] (Test Example 3: CMP Process Evaluation) For each of the manufactured polishing pads, tests were conducted as follows.

[0180] (1) Removal rate After installing a 300-mm diameter silicon wafer on which silicon oxide was deposited by a CVD process in a CMP polishing apparatus, it was set on a platen with the porous polyurethane polishing pad attached thereto with the silicon oxide film of the silicon wafer facing down. Thereafter, while feeding a calcined ceria slurry onto the polishing pad at a rate of 250 mL / min under the conditions of a polishing load of 4.0 psi and a polishing pad rotation speed of 150 rpm, the platen was rotated at 150 rpm for 60 seconds to polish the silicon oxide film. After polishing, the silicon wafer was removed from the carrier, mounted on a spin dryer, washed with deionized water (DIW), and then dried with nitrogen for 15 seconds. The dried silicon wafer was measured for the film thickness change before and after polishing using a spectroscopic interference type wafer thickness meter (model name: SI-F80R, manufactured by Keyence Corporation).

[0181] Thereafter, the removal rate was calculated using the following Mathematical Formula 1. [Equation 1] Removal rate (Å / min) = Film thickness change before and after polishing (Å) / Polishing time (min)

[0182] (2) Defects Using a CMP polishing apparatus, polishing was performed in the same manner as in the removal rate test. After polishing, the silicon wafer was transferred to a washer and treated with 1% HF, deionized water (DIW), 1% H2 NO 3 Each was washed for 10 seconds respectively. Then, it was transferred to a spin dryer, washed with deionized water (DIW), and dried with nitrogen for 15 seconds. The dried silicon wafer was measured for defect changes before and after polishing using a defect measurement device (model name: XP+, manufactured by KLA-TENCOR). Specifically, the total number of scratches, chatter marks, pits, and residues on the wafer was measured.

[0183] (3) Debris size (D50 particle size) a) Obtaining a debris aqueous solution A porous polyurethane polishing pad was attached and set on the platen of the CMP polishing apparatus. Then, except for the operation of the carrier, debris on the polishing layer was collected using only a conditioner and deionized water (DIW). The conditions were set as follows: platen speed 93 rpm, conditioner load 9 lb, conditioner speed 64 rpm, sweep speed 19 times / min, and deionized water was injected at 300 cc / min. While injecting deionized water, CI45 (pad cutting rate 80 - 90, manufactured by Sesol) was used as the conditioner disk to condition the polishing layer. The debris generated on the polishing layer 10 minutes after conditioning was collected in a solution state mixed with deionized water to obtain a 300 mL debris aqueous solution.

[0184] b) pH adjustment and particle size analysis of debris The debris aqueous solution was at a pH level of 6.0 - 6.5, and the pH was adjusted to 5.5 using a nitric acid aqueous solution. The concentration of the nitric acid aqueous solution used at this time was 35%. Using a particle size analyzer (Mastersize 3000, manufactured by Malvern) and a medium-capacity automatic wet disperser (Hydro MV, manufactured by Malvern), the D50 particle size of the debris in the debris aqueous solution was obtained. The settings of the analyzer were as follows: refractive index of the analyte as 1.55 for polyurethane, refractive index of the dispersant as 1.33 for deionized water, and stirring speed as 2500 rpm. The results are shown in the following table.

[0185]

Table 3

[0186] As can be seen from the above table, the polishing pads of Examples 1 to 3 had performance levels such as polishing rate that were equal to or higher than those of Comparative Examples 1 and 2. In particular, the debris particle size of the polishing pads of Examples 1 to 3 was measured to be smaller than that of Comparative Examples 1 and 2, and the number of defects / scratches of Examples 1 to 3 was measured to be significantly less than that of Comparative Examples 1 and 2.

Explanation of Reference Numerals

[0187] 10: Polishing layer 20: Adhesive layer 30: Support layer 100: Chamber 200: Heat exchanger 300: Distillation column

Claims

1. 1. A polishing pad comprising a polishing layer, The polishing pad has a chlorine (Cl) content of less than 10,000 ppm when a pyrolysis oil obtained by pyrolyzing the polishing layer at 320° C. for 6 hours is analyzed by combustion-ion chromatography (C-IC) based on the IEC 62321-3-2 standard.

2. 2. The polishing pad according to claim 1, wherein the chlorine (Cl) content of the pyrolysis oil analyzed by combustion ion chromatography (C-IC) based on the IEC 62321-3-2 standard is 1 ppm to 100 ppm.

3. The polishing pad according to claim 1, wherein the pyrolysis oil has a total metal component content of 1 ppm to 3000 ppm when analyzed by ICP-OES (inductively coupled plasma-optical emission spectrometer).

4. 2. The polishing pad according to claim 1, wherein the pyrolysis oil has a sulfur (S) content of 1 ppm to 100 ppm when analyzed with an elemental analyzer.

5. When the pyrolysis oil was analyzed according to the ASTM D2887 standard, The initial boiling point of the pyrolysis oil is 10°C to 50°C; 2. The polishing pad of claim 1, wherein the final boiling point of the pyrolysis oil is 400°C to 500°C.

6. The polishing layer contains a polyurethane resin, The polyurethane resin is obtained from a composition including a urethane-based prepolymer, a foaming agent, and a curing agent; 2. The polishing pad according to claim 1, wherein the urethane-based prepolymer has a terminal isocyanate group content (NCO%) of 7.5% by weight to 12% by weight.

7. The foaming agent includes a solid-phase foaming agent, and the solid-phase foaming agent includes at least one selected from the group consisting of an acrylonitrile-based copolymer, a methyl methacrylate-based copolymer, a methacrylonitrile-based copolymer, and an acrylic-based copolymer; The hardener is selected from the group consisting of diethyltoluenediamine (DETDA), 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 1,3-propanediol bis(4-aminobenzoate) (PDPAB), N,N'-bis(sec-butylamino)diphenylmethane, 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylene bis-methylanthranilate (MBNA). The polishing pad of claim 6.

8. The polishing layer is Hardness of 50 Shore D to 65 Shore D; 15N / mm ２ ~25N / mm ２ and a tensile strength of 2. The polishing pad of claim 1, having an elongation of 90% to 130%.

9. 2. The polishing pad according to claim 1, wherein when a silicon oxide film of a silicon wafer is polished with the polishing pad in a ceria slurry, the polishing rate is 2200 Å / min to 2600 Å / min. Polishing rate (Å / min) = change in film thickness before and after polishing (Å) / polishing time (min).

10. A pyrolysis oil obtained from the polishing layer of the polishing pad of claim 1, A pyrolysis oil having a chlorine (Cl) content of less than 10,000 ppm as analyzed by combustion ion chromatography (C-IC) based on the IEC 62321-3-2 standard.

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