Polishing pad and method for manufacturing same

Abstract

The present invention relates to a polishing pad used in a chemical mechanical polishing (CMP) process for a semiconductor device, and specifically, to an environmentally friendly polishing pad having a sub-pad layer containing biomass, and a method for manufacturing same.

Description

Polishing pad and method of manufacturing the same

[0001] An embodiment relates to a polishing pad used in a chemical mechanical polishing (CMP) process for semiconductor devices, and specifically, to a polishing pad having eco-friendliness by applying a sub-pad layer containing biomass and a method for manufacturing the same.

[0002] Chemical mechanical polishing (CMP) is a process in which a semiconductor substrate, such as a wafer, is attached to a head and contacts the surface of a polishing pad fixed on a platen, and the platen and the head are moved relative to each other to flatten the uneven parts of the surface of the semiconductor substrate.

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

[0004] Meanwhile, with the recent emergence of environmental issues such as climate change, public opinion is forming that companies must assume social responsibility to build a sustainable society through ESG management, including carbon neutrality. Accordingly, various companies are attempting to manufacture a variety of products by applying biomass raw materials derived from plants and other sources instead of petroleum-based raw materials.

[0005] In line with this trend, there is a need to attempt to enhance eco-friendliness by applying biomass raw materials to polishing pads that were previously manufactured using petroleum-based raw materials. Furthermore, there is a need to provide polishing pads with physical properties capable of achieving the polishing rate required in the CMP process, even when the aforementioned biomass raw materials are applied.

[0006] [Prior Art Literature]

[0007] [Patent Literature]

[0008] (Patent Document 1) Korean Published Patent Application No. 2018-0044771

[0009] The embodiment aims to provide an eco-friendly polishing pad by applying a sub-pad layer containing biomass.

[0010] In addition, the embodiment aims to provide a method for manufacturing a polishing pad that can efficiently manufacture the polishing pad.

[0011] According to one embodiment, a grinding pad is provided comprising a top pad layer; and a sub-pad layer made from a biomass-containing composition, wherein the sub-pad layer has a total biomass content of 15% by weight to 20% by weight as measured by ASTM D 6866.

[0012] According to another embodiment, a method for manufacturing a polishing pad is provided, comprising the steps of: manufacturing a biomass-containing urethane prepolymer from a urethane prepolymer composition comprising an isocyanate raw material and a polyol raw material comprising a bio-based polyol; preparing a biomass-containing composition comprising the biomass-containing urethane prepolymer, a curing agent, and a foaming agent; curing the biomass-containing composition to manufacture a sub-pad layer; and attaching the sub-pad layer to a top pad layer, wherein the sub-pad layer has a total biomass content of 15% by weight to 20% by weight as measured by ASTM D 6866.

[0013] The polishing pad according to the above embodiment includes a biomass-containing sub-pad layer, which is highly eco-friendly and has excellent physical properties required for the sub-pad layer, such as hardness, compressibility, density, and compressive modulus, thereby allowing the polishing rate to be evenly distributed according to the distance from the center in the CMP process polishing profile, and thus can improve polishing flatness.

[0014] FIG. 1 shows a cross-sectional view of a polishing pad according to one embodiment.

[0015] FIG. 2 is a semiconductor device manufacturing process using a polishing pad according to one embodiment.

[0016] In describing the embodiments below, detailed descriptions of related known configurations or functions are omitted if it is determined that such descriptions could obscure the essence of the embodiments. Additionally, the sizes of each component in the drawings may be exaggerated or omitted for illustrative purposes and may differ from the actual sizes applied.

[0017] In this specification, the description that one component is connected or coupled with another component includes both direct and indirect formation, connection, or coupling between these components through the interposition of another component.

[0018] In this specification, terms referring to each component are used to distinguish them from other components and are not intended to limit the embodiments. Additionally, in this specification, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0019] In this specification, terms such as "first," "second," etc. are used to describe various components, and said components should not be limited by said terms. These terms are used for the purpose of distinguishing one component from another.

[0020] In this specification, the use of the term "comprising" is intended to specify characteristics, regions, steps, processes, elements, and components, and unless specifically stated otherwise, it does not exclude the existence or addition of other characteristics, regions, steps, processes, elements, or components.

[0021] For convenience, the molecular weights of compounds or polymers described in this specification are indicated in units of molar mass, but they may be understood as relative masses based on carbon-12. Furthermore, the molecular weights of polymers described in this specification may be interpreted as number-average molecular weight or weight-average molecular weight, for example, as weight-average molecular weight.

[0022] In numerical ranges defining the size, physical properties, etc., of components described in this specification, if a numerical range in which only the upper limit is defined and a numerical range in which only the lower limit is defined are separately exemplified, it should be understood that a numerical range combining these upper and lower limits is also included in the exemplary range.

[0023] In this specification, the term "bio-based" component refers to a component obtained by using biomass derived from plants, etc., as wholly or partially as a raw material, rather than fossil fuel-based materials such as petroleum; specifically, carbon-14, a radioactive carbon isotope that is not present in fossil fuel-based materials such as petroleum but exists only in bio-based materials ( 14 It is a component containing C).

[0024] For example, "bio-based polyol" refers to a polyol obtained using biomass derived from plants, etc., as all or part of the raw material, and radiocarbon ( 14 Since it contains C), it can be distinguished from polyols obtained from fossil fuel-based materials that do not contain it.

[0025] The above biomass is a concept that broadly encompasses biologically derived materials such as animal and plant resources like trees, flowers, corn, sugarcane, grass, whale oil, and algae; or organic waste resources like livestock manure, food waste, and sawdust, as well as radioactive carbon ( 14 It may include C).

[0026]

[0027] Polishing pad

[0028] A polishing pad (100) according to one embodiment comprises, as illustrated in FIG. 1, a top pad layer (10); and a sub-pad layer (30) made from a biomass-containing composition. Additionally, the polishing pad (100) may further include an adhesive layer (20) as needed.

[0029]

[0030] Biomass-containing composition

[0031] The above biomass-containing composition includes a urethane prepolymer. The above biomass-containing composition may include a urethane prepolymer comprising a polyol and an isocyanate, and more specifically, may be a composition comprising a urethane prepolymer, a curing agent, and a foaming agent.

[0032] The above urethane prepolymer may be a prepolymer obtained through the reaction of a polyol raw material comprising a bio-based polyol and an isocyanate raw material. Specifically, the above urethane prepolymer may be prepared from a urethane prepolymer composition comprising a polyol raw material comprising a bio-based polyol and an isocyanate raw material.

[0033] The above polyol raw materials and isocyanate raw materials may include biomass. For example, the polyol raw material may include bio-based polymer polyols and bio-based monomer polyols. Additionally, the above isocyanate raw material may include bio-based isocyanates.

[0034] The above biomass refers to an energy source obtained from living organisms, specifically animal and plant resources such as trees, flowers, corn, sugarcane, grass, whale oil, algae, etc.; or obtained from organic waste resources such as livestock manure, food waste, sawdust, etc., to produce biocarbon (radiocarbon ( 14 It can mean an energy source including C).

[0035] Meanwhile, the biomass (biocarbon) content described below may refer to values ​​measured in accordance with ASTM D 6866. The ASTM D 6866 standard is a standard analytical method for measuring the biomass (biocarbon) content of solid, liquid, or gaseous samples using radiometric dating or accelerator mass spectrometry (AMS) methods.

[0036] The above radiocarbon dating method may include the following process. Specifically, a sample (specimen) that has undergone pretreatment (e.g., removal of foreign substances) is placed in a special vacuum device and burned to produce carbon dioxide. Next, molten lithium is mixed to produce lithium carbide, which is then cooled and reacted with water to produce acetylene gas. Next, the acetylene gas is purified and converted into benzene using a silica-alumina catalyst. Next, benzene, which is 92% carbon, is mixed with a scintillation chemical, and its radioactivity is measured using a liquid scintillation counter for about two days.

[0037] The above accelerated mass spectrometry method may include the following process. Specifically, a sample (specimen) that has undergone pretreatment (e.g., removal of foreign substances) is burned to produce purified carbon dioxide, and then reacted with hydrogen in a vacuum chamber made of special glass to produce graphite. Then, the graphite, which is 100% carbon, is placed in an accelerated mass spectrometer and radioactivity is measured for about 30 minutes.

[0038]

[0039] Polyol raw materials

[0040] Bio-based polymer polyol

[0041] The above bio-based polymer polyol is derived from biomass and is a radioactive carbon isotope, carbon-14 ( 14 A polymer polyol comprising C) may have two or more hydroxyl groups (OH) and may have two or more, five or more, or ten or more repeating units.

[0042] Specifically, the biopolymer polyol may include one or more selected from the group consisting of bio-based polyether polyols, bio-based polyester polyols, bio-based polycarbonate polyols, and bio-based polycaprolactam polyols.

[0043] When the characteristics of the above bio-based polymer polyol, such as molecular weight, hydroxyl value (OH-value), and number of functional groups, are controlled within a certain range, it may be more advantageous to provide a polishing pad with excellent uniformity of CMP process results.

[0044] For example, the molecular weight of the bio-based polymer polyol may be 300 g / mol or more, 400 g / mol or more, 450 g / mol or more, 500 g / mol or more, 600 g / mol or more, 700 g / mol or more, or 800 g / mol or more, and may also be 5000 g / mol or less, 4000 g / mol or less, 3000 g / mol or less, 2700 g / mol or less, 2300 g / mol or less, 1800 g / mol or less, 1500 g / mol or less, or 1200 g / mol or less.

[0045] As a specific example, the bio-based polymer polyol may have a molecular weight of 400 g / mol to 3000 g / mol.

[0046] More specifically, the molecular weight of the bio-based polymer polyol may be 450 g / mol to 2700 g / mol, 500 g / mol to 2300 g / mol, 600 g / mol to 1800 g / mol, 700 g / mol to 1500 g / mol, or 800 g / mol to 1200 g / mol.

[0047] In addition, the hydroxyl value (OH-value) of the above bio-based polymer polyol may be, for example, 35 mgKOH / g or more, 45 mgKOH / g or more, 60 mgKOH / g or more, 70 mgKOH / g or more, 80 mgKOH / g or more, or 90 mgKOH / g or more, and may also be 250 mgKOH / g or less, 230 mgKOH / g or less, 200 mgKOH / g or less, 180 mgKOH / g or less, 150 mgKOH / g or less, or 130 mgKOH / g or less.

[0048] In one embodiment, the bio-based polymer polyol may have a hydroxyl value (OH-value) of 35 mgKOH / g to 250 mgKOH / g.

[0049] More specifically, the hydroxyl value (OH-value) of the bio-based polymer polyol may be 45 mgKOH / g to 230 mgKOH / g, 60 mgKOH / g to 200 mgKOH / g, 70 mgKOH / g to 180 mgKOH / g, 80 mgKOH / g to 150 mgKOH / g, or 90 mgKOH / g to 130 mgKOH / g.

[0050] The number of functional groups of the above bio-based polymer polyol may be 2 or more or 3 or more, and may also be 10 or less, 5 or less, 4 or less, or 3 or less.

[0051] In one embodiment, the number of functional groups of the bio-based polymer polyol may be 2 to 4.

[0052] Examples of the above bio-based polymer polyols available on the market include SK Chemical’s ECOTRION H2000 and ECOTRION H1000; SK Pucore’s BI-550 and B-1184; BASF’s Sovermol 1102, Sovermol 1005, Sovermol 805 and Sovermol 815; NOROO’s BP-04 and BP-05; Croda’s Priplast 2033 and Priplast 1838; ALLESSA’s Velvetol H500, Velvetol H1000, Velvetol H2000 and Velvetol H2700; or combinations thereof.

[0053] The biomass content in the above bio-based polymer polyol may be, for example, 10 wt% or more, 20 wt% or more, 30 wt% or more, 50 wt% or more, 60 wt% or more, 70 wt% or more, or 80 wt% or more, and may also be 100 wt% or less, 90 wt% or less, or 85 wt% or less. Specifically, the biomass content based on the total weight of the above bio-based polymer polyol may be 20 wt% to 100 wt%, and more specifically, 25 wt% to 100 wt%, 40 wt% to 100 wt%, 50 wt% to 100 wt%, 60 wt% to 100 wt%, 70 wt% to 100 wt%, or 80 wt% to 100 wt%. As the biomass content of the above bio-based polymer polyol is within the above range, the results of the CMP process appear uniformly, and a polishing pad with superior eco-friendliness can be provided.

[0054]

[0055] Bio-based monomer polyols

[0056] The above polyurethane resin may additionally include one or more bio-based monomer polyols.

[0057] Specifically, the polyurethane resin may be manufactured from a composition comprising one or more bio-based monomer polyols.

[0058] Accordingly, the polyurethane resin may include repeating units derived from the bio-based monomer polyol, along with repeating units derived from the bio-based polymer polyol.

[0059] The above bio-based monomer polyol is derived from biomass and is a radioactive carbon isotope, carbon-14 ( 14 A monomeric polyol containing C) having two or more hydroxyl groups (OH).

[0060] Specifically, the bio-based monomer polyol may include one or more selected from the group consisting of bio-based ethylene glycol, bio-based diethylene glycol, bio-based 1,2-propylene glycol, bio-based 1,3-propanediol, bio-based 2-methyl-1,3-propanediol, bio-based 1,3-butanediol, bio-based 1,4-butanediol, bio-based 2,3-butanediol, bio-based 1,5-pentanediol, bio-based 1,9-nonanediol, bio-based 1,10-decanediol, and bio-based isosorbide.

[0061] More specifically, the bio-based monomer polyol may include one or more selected from the group consisting of bio-based 1,3-propanediol, bio-based 1,3-butanediol, bio-based 1,4-butanediol, bio-based 2,3-butanediol, bio-based 1,5-pentanediol, bio-based 1,9-nonanediol, bio-based 1,10-decanediol, and bio-based isosorbide.

[0062] In this way, by including a bio-based monomer polyol, the crosslinking density of the urethane prepolymer is increased, thereby providing a polishing pad in which the hardness and CMP process results are uniform.

[0063] The above bio-based monomer polyol may have a molecular weight of 50 g / mol to 200 g / mol, specifically 55 g / mol to 180 g / mol, 60 g / mol to 150 g / mol, 65 g / mol to 130 g / mol, 70 g / mol to 100 g / mol, or 75 g / mol to 90 g / mol. When the molecular weight of the above bio-based monomer polyol is within the above range, a polishing pad with excellent eco-friendliness can be provided while the results of the CMP process appear uniform.

[0064] These bio-based monomer polyols may have a biomass content of 50% or more, 80% or more, or 90% or more based on the total weight of the bio-based monomer polyol, specifically 80% to 100%, and more specifically 100%.

[0065] When the biomass content of the above biomonomer polyol is within the above range, the results of the CMP process appear uniform, which may be more advantageous for providing an eco-friendly polishing pad.

[0066]

[0067] Other polyols

[0068] The above polyol raw material may further include petroleum-based polyols in addition to the above bio-based polymer polyol and bio-based monomer polyol.

[0069] Specifically, the above polyol may further include one or more selected from the group consisting of petroleum-based polymer polyols and petroleum-based monomer polyols.

[0070] The above petroleum-based polymer polyol may include one or more selected from the group consisting of commonly known polyether polyols, polyester polyols, polycarbonate polyols, and polycaprolactam polyols.

[0071] In addition, the above petroleum-based monomer polyol may include one or more selected from the group consisting of commonly known ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, n-butanol, isobutanol, 1,5-pentanediol, 1,6-hexanediol, 2-octanol, 1,9-nonanediol, and 1,10-decanediol.

[0072] When the polyol in the polyurethane resin includes both the bio-based polyol (a) and the petroleum-based polyol (b), the mixing ratio (a:b) of these may be a molar ratio of 1:0.65 to 1:3, a molar ratio of 1:0.65 to 1:1.5, a molar ratio of 1:0.65 to 1:1.25, a molar ratio of 1:0.65 to 1:0.92, a molar ratio of 1:0.68 to 1:0.90, a molar ratio of 1:0.72 to 1:0.88, a molar ratio of 1:0.75 to 1:0.86, or a molar ratio of 1:0.80 to 1:0.85.

[0073] Within the above mixing ratio range, it is more advantageous to provide a polishing pad with excellent eco-friendliness while ensuring uniform results from the CMP process.

[0074]

[0075] Isocyanate raw materials

[0076] Bio-based isocyanates

[0077] The above isocyanate raw material may include bio-based isocyanates.

[0078] The above bio-based isocyanate is derived from biomass, contains radiocarbon, and may have two or more isocyanate groups (NCO).

[0079] The terminal NCO content (NCO%) of the above bio-based isocyanate may be 5 wt% or more, 10 wt% or more, 15 wt% or more, or 20 wt% or more, and may also be 50 wt% or less, 40 wt% or less, or 30 wt% or less. In one embodiment, the terminal NCO content (NCO%) of the above bio-based isocyanate may be 20 wt% to 30 wt%, and more specifically, 21 wt% to 28 wt%, 22 wt% to 26 wt%, or 23 wt% to 25 wt%.

[0080] If the NCO% of the above bio-based isocyanate is within the above range, a polishing pad with superior hardness, durability, etc. can be provided.

[0081] The above bio-based isocyanate may be one or more selected from the group consisting of bio-based hexamethylene diisocyanate (bio-based HDI), bio-based 4,4'-diphenylmethane diisocyanate (bio-based MDI), and bio-based 1,5-pentamethylene diisocyanate (bio-based PDI), and the type of bio-based isocyanate may vary depending on the intent of the technician or the emergence of new technology. In one embodiment, the bio-based isocyanate may include bio-based 1,5-pentamethylene diisocyanate.

[0082] Examples of the aforementioned bio-based isocyanates available on the market include STABiO TM ...can be cited.

[0083] The bio-based isocyanate may have a biomass content of 60 wt% or more, 63 wt% or more, or 65 wt% or more as measured according to ASTM D6866-04, and may also have a biomass content of 100 wt% or less, 95 wt% or less, 90 wt% or less, 80 wt% or less, or 75 wt% or less. Specifically, the biomass content based on the total weight of the bio-based isocyanate may be 60 wt% to 100 wt%, and more specifically, 60 wt% to 90 wt%, 63 wt% to 80 wt%, or 65 wt% to 75 wt%. When the biomass content of the bio-based isocyanate is within the above range, a polishing pad with superior eco-friendliness can be provided while the results of the CMP process appear uniform.

[0084] The above bio-based isocyanate may have a viscosity at 25°C measured according to ASTM D6866-04 of 100 mPa·s or more, 200 mPa·s or more, 300 mPa·s or more, 400 mPa·s or more, 500 mPa·s or more, and 5000 mPa·s or less, 4000 mPa·s or less, 3000 mPa·s or less, 2500 mPa·s or less, and 2000 mPa·s or less. For example, the above bio-based isocyanate may have a viscosity at 25°C measured according to ASTM D6866-04 of 100 mPa·s to 5000 mPa·s or 500 mPa·s to 2000 mPa·s. As the viscosity of the above bio-based isocyanate at 25°C, measured according to ASTM D6866-04, satisfies the above range, a polishing pad can be provided in which the results of the CMP process appear uniform.

[0085]

[0086] Other isocyanates

[0087] The above isocyanate raw material may further include petroleum-based isocyanates.

[0088] Specifically, the isocyanate may include one or more selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates. More specifically, the isocyanate may include one or more selected from the group consisting of aromatic diisocyanates and alicyclic diisocyanates.

[0089] For example, the above isocyanates are toluene diisocyanate (TDI), naphthalene-1,5-diisocyanate, p-phenylene diisocyanate, tolidin diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, and 4,4'-methylene dicyclohexyl diisocyanate (H 12 It may include one or more selected from the group consisting of MDI and isophorone diisocyanate.

[0090]

[0091] Curing agents and foaming agents

[0092] The above biomass-containing composition may further include a curing agent and a foaming agent in addition to the urethane prepolymer.

[0093] The above curing agent may include a compound that undergoes a curing reaction with the urethane prepolymer.

[0094] Specifically, the curing agent may include one or more selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, and aliphatic alcohols.

[0095] More specifically, the curing agent is 4,4'-methylenebis(2-chloroaniline) (4,4'-methylenebis(2-chloroaniline)), diethyltoluenediamine, diaminodiphenylmethane, dimethyl thio-toluene diamine, propanediol bis(p-aminobenzoate)), diaminodiphenyl sulfone, m-xylylenediamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, and It may include one or more selected from the group consisting of bis(4-amino-3-chlorophenyl)methane.

[0096] The above blowing agent is intended to form a porous structure and may include one or more selected from the group consisting of solid blowing agents, liquid blowing agents, and gaseous blowing agents (e.g., gases such as nitrogen, argon, helium, and carbon dioxide).

[0097] Specifically, the foaming agent may be a solid foaming agent containing expandable particles. The expandable particles are particles having the characteristic of being expandable by heat or pressure, and their final size may be determined by the applied heat or pressure. Specifically, the expandable particles may include expanded particles, unexpanded particles, or a combination thereof.

[0098] The above thermally expanded particles are particles that have been pre-expanded by heat, and may refer to particles whose final size is determined by expansion caused by applied heat or pressure.

[0099] These expandable particles may include an outer shell made of resin material and an expansion-inducing component present inside the outer shell.

[0100] The outer shell made of the above resin material may include a thermoplastic resin. Specifically, the thermoplastic resin may be one or more selected from the group consisting of vinylidene chloride copolymers, acrylonitrile copolymers, methacrylonitrile copolymers, and acrylic copolymers.

[0101] The above-mentioned swelling-inducing component may include one or more selected from the group consisting of hydrocarbon compounds, chlorofluoro compounds, and tetraalkylsilane compounds.

[0102] Specifically, the hydrocarbon compound may include one or more selected from the group consisting of ethane, ethylene, propane, propene, n-butane, isobutene, n-butene, isobutene, n-pentane, isopentane, neopentane, n-hexane, heptane, and petroleum ether.

[0103] The above chlorofluoro compound may include one or more selected from the group consisting of trichlorofluoromethane (CCl3F), dichlorodifluoromethane (CCl2F2), chlorotrifluoromethane (CClF3), and dichlorotetrafluoroethylene (CClF2-CClF2).

[0104] The above tetraalkylsilane compound may include one or more selected from the group consisting of tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, and trimethyl-n-propylsilane.

[0105] Such solid foaming agents may have an average particle size of 5 μm to 200 μm, specifically 10 μm to 100 μm, 15 μm to 70 μm, or 20 μm to 45 μm. Here, if the solid foaming agent contains the thermally expanded particles as the expandable particles, the average particle size may refer to the average particle size of the thermally expanded particles themselves. Additionally, if the solid foaming agent contains the unexpanded particles as the expandable particles, the average particle size may refer to the average particle size of the particles after expansion by heat or pressure.

[0106]

[0107] Top pad layer

[0108] The top pad layer (10) included in the polishing pad (100) according to the embodiment plays the role of polishing a semiconductor substrate (e.g., wafer) that is to be polished.

[0109] The material of the top pad layer (10) can be any material that has the physical properties required for the chemical mechanical polishing (CMP) process of a semiconductor device, but specifically, polyurethane is suitable, and commercially available products may also be applied.

[0110] Meanwhile, for the sake of eco-friendliness, it may be considered to manufacture the top pad layer (10) using a biomass-containing composition, similar to the sub pad layer (30). The range of components applicable to the manufacture of the top pad layer (10) is the same as the components of the polyol raw material, isocyanate raw material, curing agent, and foaming agent described above.

[0111] However, if a separate distinction regarding the components is required, the components used in the top pad layer (10) may be referred to as the first composition, the first isocyanate raw material, the first polyol raw material, the first bio-based isocyanate, the first bio-based polymer polyol, and the first bio-based monomer polyol, and the components used in the sub pad layer (30) may be referred to as the second composition, the second isocyanate raw material, the second polyol raw material, the second bio-based isocyanate, the second bio-based polymer polyol, and the second bio-based monomer polyol to distinguish them.

[0112] In reacting the first polyol raw material (x) and the first isocyanate raw material (y) to manufacture the top pad layer (10), the reaction ratio (x:y) is not particularly limited, but considering the overall physical properties of the top pad layer (10), specifically, it may be a weight ratio of 1:2 to 1:14, a weight ratio of 1:3 to 1:12, a weight ratio of 1:4 to 1:10, or a weight ratio of 1:5 to 1:8.

[0113]

[0114] Sub-pad layer

[0115] The sub-pad layer (30) included in the polishing pad according to the embodiment is provided below the top pad layer (10) and serves to stably support the top pad layer (10) while absorbing and / or dispersing the impact applied to the top pad layer (10).

[0116] The sub-pad layer (30) may have a total biomass content of 15 wt% or more, 16 wt% or more as measured by ASTM D 6866, and may have a total biomass content of 20 wt% or less, 19 wt% or less, or 18 wt% or less. For example, the sub-pad layer (30) may have a total biomass content of 15 wt% to 20 wt% or 16 wt% to 18 wt% as measured by ASTM D 6866. The sub-pad layer (30) has excellent eco-friendliness as the biomass content is controlled within the above-mentioned range.

[0117] The range of components applicable to the manufacture of the above sub-pad layer (30) is the same as the components of the aforementioned polyol raw material, isocyanate raw material, curing agent, and foaming agent.

[0118] Meanwhile, when reacting the second polyol raw material (z) and the second isocyanate raw material (w) to manufacture the sub-pad layer (30), the reaction ratio (z:w) is not particularly limited, but considering the overall physical properties of the sub-pad layer (30), specifically, it may be a weight ratio of 1:1 to 1:2, a weight ratio of 1:1.4 to 1:2, a weight ratio of 1:1.6 to 1:1.9, or a weight ratio of 1:1.7 to 1:1.9.

[0119] In addition, the ratio of the moles of the bio-containing raw material to the total moles of the second polyol raw material and the second isocyanate raw material may be 0.15 to 0.20, 0.16 to 0.19, or 0.16 to 0.18. Specifically, the ratio (M) may be a value calculated according to Formula 1 below. As the ratio (M) is within the above range, a polishing pad with excellent eco-friendliness while having the physical properties required in the CMP process can be provided.

[0120] [Equation 1]

[0121] M = (M BP1 + M BI1 ) / (M BP1 + M P2 + M BI1 + M I2 )

[0122] In the above Equation 1, M BP1 is the number of moles (total number of moles) of the bio-based polyol included in the second urethane prepolymer composition, and M P2 is the moles (total moles) of petroleum-based polyol included in the second urethane prepolymer composition, and M BI is the moles (total moles) of bio-based isocyanate included in the second urethane prepolymer composition, and M I2 is the number of moles (total number of moles) of petroleum-based isocyanate included in the second urethane prepolymer composition.

[0123] The thickness of the sub-pad layer (30) is not specifically limited, but specifically may be 0.1 mm to 5 mm, 0.2 mm to 4 mm, 0.3 mm to 3 mm, or 0.5 mm to 2 mm. In addition, the hardness (Shore D) of the sub-pad layer (30) is not specifically limited, but specifically may be 40 Shore D to 90 Shore D or 45 Shore D to 85 Shore D. In addition, the average pore size formed in the sub-pad layer (30) is not specifically limited, but specifically may be 10 μm to 40 μm or 15 μm to 35 μm. As the thickness, hardness, and average pore size of the sub-pad layer (30) are each within the above ranges, the CMP process can be performed stably and the polishing pad (100) can be made lighter.

[0124] Meanwhile, the compression ratio (%) of the sub-pad layer (30) may be 7.0% to 8.5% or 8.0% to 8.5%. In addition, the density (g / cm²) of the sub-pad layer (30) 3 ) is 0.2 g / cm 3 Up to 0.3 g / cm 3 , 0.25 g / cm 3 Up to 0.29 g / cm³ 3 , 0.26 g / cm 3 Up to 0.29 g / cm³ 3 or 0.27 g / cm³ 3 Up to 0.29 g / cm³ 3 It may be. Also, the compressive elasticity modulus (%) of the sub-pad layer (30) may be 75% to 85%, 76% to 84%, 77% to 83%, 78% to 82%, 79% to 81%, or 79% to 80%. Compression rate (%), density (g / cm³) of the sub-pad layer (30). 3As the ) and compressive modulus (%) satisfy the above range, the polishing rate according to the distance from the center in the CMP process polishing profile is evenly distributed, thereby improving polishing flatness, and in particular, the polishing profile characteristics of the polishing pad edge can be improved.

[0125]

[0126] adhesive layer

[0127] An adhesive layer (20) further included in the polishing pad (100) according to the embodiment is provided between the top pad layer (10) and the sub pad layer (30) and serves to bond the top pad layer (10) and the sub pad layer (30). Furthermore, the adhesive layer (20) can also serve to prevent polishing slurry supplied to the top pad layer (10) from leaking into the sub pad layer (30). Such an adhesive layer (20) can be manufactured (formed) using a hot melt adhesive composition.

[0128] The above hot melt adhesive composition may include a commonly known hot melt adhesive. Specifically, the hot melt adhesive may include one or more selected from the group consisting of polyurethane resins, polyester resins, ethylene-vinyl acetate resins, polyamide resins, and polyolefin resins.

[0129] The thickness of the adhesive layer (20) is not specifically limited, but specifically may be 5 μm to 30 μm, 10 μm to 30 μm, 20 μm to 27 μm, or 23 μm to 25 μm. As the thickness of the adhesive layer (20) is within the above range, the bonding force (adhesion force) between the top pad layer (10) and the sub pad layer (30) can be secured to the required level.

[0130]

[0131] Method for manufacturing a polishing pad

[0132] A method for manufacturing a polishing pad according to an embodiment comprises the steps of: preparing a biomass-containing urethane prepolymer from a urethane prepolymer composition comprising an isocyanate raw material and a polyol raw material comprising a bio-based polyol; preparing a biomass-containing composition comprising the biomass-containing urethane prepolymer, a curing agent, and a foaming agent; curing the biomass-containing composition to produce a sub-pad layer; and attaching the sub-pad layer to a top pad layer, wherein the sub-pad layer is characterized by having a total biomass content of 15% to 20% by weight as measured by ASTM D 6866.

[0133] Accordingly, the polishing pad may have a sub-pad layer (30) in which a urethane prepolymer containing the bio-based polymer polyol is cured.

[0134] First, a biomass-containing urethane prepolymer is prepared from a urethane prepolymer composition comprising an isocyanate raw material and a polyol raw material comprising a bio-based polyol. Specifically, a urethane prepolymer composition comprising a polyol raw material comprising the bio-based polymer polyol and the isocyanate raw material can be introduced into a reactor and prepolymerization can be carried out to prepare the urethane prepolymer. The reaction conditions are not particularly limited, but the reaction temperature may be 70°C to 90°C (specifically 75°C to 85°C), and the reaction time may be 1 hour to 4 hours (specifically 2 hours to 3 hours). Meanwhile, the descriptions for the polyol raw material and the isocyanate raw material, respectively, may be applied in the same manner to the polyol raw material and isocyanate raw material exemplified in the polishing pad above.

[0135] Next, a biomass-containing composition is prepared comprising a biomass-containing urethane prepolymer, a curing agent, and a foaming agent. The biomass-containing composition may include a biomass-containing urethane prepolymer, a curing agent, and a foaming agent, and a surfactant and a reaction rate regulator may be further added during the manufacturing process. The surfactant is not particularly limited, but specifically, it may be a silicone-based surfactant. The above reaction rate regulators are not particularly limited, but specifically include 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''-pentamethyldiethyldimethylaminoethylamine, dimethylaminopropylamine, benzyldimethylamine, N-ethylmorpholine, N,N-dimethylaminoethylmorpholine, N,N-dimethylcyclohexylamine, 2-methyl-2-azanobornenein, dibutyltin dilaurate, stannus octoate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin maleate, It may include one or more selected from the group consisting of dibutyltin di-2-ethylhexanoate and dibutin dimercaptide.

[0136] Subsequently, the biomass-containing composition is cured to produce a sub-pad layer (30). To do this, the urethane prepolymer, curing agent, and foaming agent can be filled into their respective injection lines and mixed to produce the sub-pad layer (30). Specifically, the mixing can be performed at a speed of 1,000 rpm to 10,000 rpm, 2,500 rpm to 8,500 rpm, or 4,000 rpm to 7,000 rpm. Here, the foaming agent may be mixed through an injection line separate from the biomass-containing urethane prepolymer injection line, or may be mixed with the biomass-containing urethane prepolymer in advance before the biomass-containing urethane prepolymer is filled into the injection line. The descriptions for the curing agent and the foaming agent, respectively, can be applied in the same way as the descriptions for the curing agent and foaming agent exemplified in the polishing pad above. For example, the content of the curing agent may be 15 to 55 parts by weight per 100 parts by weight of the urethane prepolymer, and specifically, 20 to 50 parts by weight, 25 to 45 parts by weight, or 30 to 40 parts by weight. When the content of the curing agent is within the above range, it may be more advantageous to implement a polishing pad equipped with a sub-pad layer (30) having excellent physical properties. Meanwhile, the reaction ratio (curing reaction ratio) between the urethane prepolymer and the curing agent is not particularly limited, but specifically, it may be an equivalent ratio of 1:0.5 to 1:1.3, an equivalent ratio of 1:0.6 to 1:1.2, an equivalent ratio of 1:0.7 to 1:1.1, or an equivalent ratio of 1:0.8 to 1:1. As the curing reaction is carried out at the above reaction ratio, the curing reaction is optimized, thereby providing a polishing pad equipped with a sub-pad layer (30) having the physical properties required in the CMP process. The step of manufacturing the sub-pad layer (30) may include the process of introducing a composition mixed with the urethane prepolymer, curing agent, and foaming agent into a mold and causing a curing reaction.The above curing reaction conditions are not particularly limited, but the curing reaction temperature is 60 ℃ to 130 ℃, specifically 75 ℃ to 110 ℃, and the mold pressure is 50 kg / m. 2 Up to 260 kg / m² 2 (Specifically, 80 kg / m² 2 up to 180 kg / m² 2 It can be.

[0137] Next, a top pad layer (10) is attached to the sub pad layer (30). The top pad layer (10) may be manufactured using a urethane prepolymer composition containing isocyanate raw materials and polyol raw materials, as in the method for manufacturing the sub pad layer (30), or it may be commercially available. Specifically, the process of attaching the top pad layer (10) to the sub pad layer (30) may be a method of attaching the top pad layer (10) to the sub pad layer (30) using a hot melt adhesive composition, and in this process, an adhesive layer (20) may be formed between the sub pad layer (30) and the top pad layer (10).

[0138]

[0139] Chemical Mechanical Polishing (CMP)

[0140] A semiconductor device can be manufactured through chemical mechanical polishing using a polishing pad according to the above embodiment.

[0141] A method for manufacturing a semiconductor device according to one embodiment includes the step of polishing the surface of a semiconductor substrate using a polishing pad. Specifically, the method for manufacturing a semiconductor device may include the step of providing a polishing pad according to the embodiment; and the step of polishing the surface of the semiconductor substrate by rotating relative to each other so that the polishing surface of the polishing layer and the surface of the semiconductor substrate come into contact with each other.

[0142] FIG. 2 illustrates a semiconductor device manufacturing process using a polishing pad according to one embodiment. Referring to FIG. 2, after mounting the polishing pad (100) according to the one embodiment onto a platen (200), a semiconductor substrate (600) to be polished is placed on the polishing pad (100). At this time, the surface to be polished of the semiconductor substrate (600) is in direct contact with the polishing surface of the polishing pad (100). For polishing, a polishing slurry (400) may be sprayed onto the polishing pad through a nozzle. Subsequently, the semiconductor substrate (600) and the polishing pad (100) rotate relative to each other so that the surface of the semiconductor substrate (600) can be polished. At this time, the rotation direction of the semiconductor substrate (600) and the rotation direction of the polishing pad (100) may be the same direction or opposite directions. The semiconductor substrate (600) can be mounted on a polishing head (510) and pressed against the polishing surface of the polishing pad (100) with a predetermined load, and then the surface thereof can be polished. Additionally, the method for manufacturing the semiconductor device may further include a step of processing the polishing surface of the polishing pad (100) through a conditioner (300) simultaneously with the polishing of the semiconductor substrate (600) in order to maintain the polishing surface of the polishing pad (100) in a state suitable for polishing.

[0143] The following embodiments are described, but the scope of implementation is not limited to these.

[0144]

[0145] Examples

[0146] <Example 1 and Comparative Examples 1 to 2>

[0147] Example 1

[0148] (1) Manufacturing of top pad

[0149] As a first isocyanate raw material, 165 parts by weight of toluene diisocyanate (TDI) and 4,4'-methylene dicyclohexyl diisocyanate (H 1225 parts by weight of MDI, 285 parts by weight of a bio-based polymer polyol (ECOTRION H1000, SK Chemical Co., Ltd. (molecular weight 1000 g / mol, OH-value 102.0~124.7, biomass content 100 wt% based on total weight of bio-based polymer polyol) as a first polymer polyol raw material, and 25 parts by weight of diethylene glycol as a first monomer polyol raw material were added to a 4-necked flask and reacted at 80 ℃ for 3 hours to produce a first urethane prepolymer having an NCO% of 9%.

[0150] In a casting machine equipped with an inert gas injection line, the first urethane prepolymer prepared in step (1) was filled into the prepolymer tank, and bis(4-amino-3-chlorophenyl)methane (Ishihara Co.) was filled into the curing agent tank, and nitrogen (N2) was applied as the inert gas. Each raw material was stirred while being fed into the mixing head at a constant speed through each input line. At this time, the urethane prepolymer and the curing agent were fed in an equivalent ratio of 1:1, and the inert gas nitrogen (N2) was injected at a rate of 0.5 to 1.5 L / min. The stirred raw material was extruded into a mold (1,000 mm × 1,000 mm × 3 mm) preheated to 80 ℃ at an extrusion rate of 10 kg / min, and then cast at 120 ℃ to obtain a molded body. Subsequently, the top and bottom ends of the molded body were each cut to a thickness of 0.5 mm to obtain a top pad (top pad layer) with a thickness of 2 mm (specific gravity 0.82 g / cc, average pore size 23.6 μm).

[0151] (2) Manufacturing of sub-pads

[0152] 180 parts by weight of bio-based PDI (STABiO PDI, MITSUI CHEMICALS) as the second isocyanate raw material, 300 parts by weight of bio-based polymer polyol (ECOTRION H1000, SK Chemical) as the second polymer polyol, and 20 parts by weight of bio-based 1,3-PDO as the second monomer polyol were added to a 4-necked flask and reacted at 80°C for 3 hours to produce a second urethane prepolymer having an NCO% of 9%.

[0153] In a casting machine equipped with an inert gas injection line, the second urethane prepolymer was filled into the prepolymer tank and bis(4-amino-3-chlorophenyl)methane (Ishihara Co.) was filled into the curing agent tank, and nitrogen (N2) was applied as the inert gas. Each raw material was stirred while being fed into the mixing head at a constant speed through each input line. At this time, the urethane prepolymer and the curing agent were fed in an equivalent ratio of 1:1, and the inert gas nitrogen (N2) was injected at a rate of 0.5 L / min to 1.5 L / min. The stirred raw material was extruded into a mold (1,000 mm × 1,000 mm × 3 mm) preheated to 80 ℃ at an extrusion rate of 10 kg / min, and then cast at 120 ℃ to obtain a molded body. Subsequently, the top and bottom of the molded body were cut to obtain a sub-pad (sub-pad layer) with a thickness of 1.1 mm.

[0154] (3) Attachment of sub-pad layer and top pad layer

[0155] A polishing pad (thickness: 3.32 mm) having a structure of a top pad layer / adhesive layer / sub-pad layer was manufactured by bonding the sub-pad to the top pad using a hot melt adhesive. Meanwhile, some of the sub-pads were prepared without being attached to the top pad for the experiment.

[0156]

[0157] Comparative Example 1

[0158] (1) Manufacturing of top pad

[0159] A top pad with a thickness of 2 mm was manufactured using the same method as in Example 1 above.

[0160] (2) Manufacturing of sub-pads

[0161] A sub-pad (thickness: 1.1 mm) was prepared by impregnating a polyester fiber nonwoven fabric with polyurethane resin.

[0162] (3) Manufacturing of polishing pads

[0163] A polishing pad (thickness: 3.32 mm) was manufactured by attaching a sub-pad and a top pad in the same manner as in Example 1 above. Meanwhile, some of the sub-pads were prepared without being attached to the top pad for the experiment.

[0164]

[0165] Comparative Example 2

[0166] (1) Manufacturing of top pad

[0167] A top pad with a thickness of 2 mm was manufactured using the same method as in Example 1 above.

[0168] (2) Manufacturing of sub-pads

[0169] A subpad (thickness: 1.1 mm) was prepared in the same manner as in Example 1, except that 160 parts by weight of toluene diisocyanate (TDI) and 25 parts by weight of H12MDI were used as the second isocyanate raw materials, 300 parts by weight of PTMG as the second polymer polyol, and 25 parts by weight of bio 1,3-PDO as the second monomer polyol.

[0170] (3) Attach the sub-pad layer and the top pad layer

[0171] A polishing pad (thickness: 3.32 mm) was manufactured by attaching a sub-pad and a top pad in the same manner as in Example 1 above. Meanwhile, some of the sub-pads were prepared without being attached to the top pad for the experiment.

[0172]

[0173] <Physical properties of the sub-pad>

[0174] Experimental Example 1: Hardness

[0175] The hardness of the subpads prepared in Example 1, Comparative Example 1, and Comparative Example 2 was measured. Specifically, the subpads were cut to a width of 5 cm and a length of 5 cm, stored at 25°C for 12 hours, and then the Shore D hardness was measured using a durometer.

[0176]

[0177] Experimental Example 2: Compression Ratio

[0178] For the sub-pads prepared in Example 1, Comparative Example 1, and Comparative Example 2 above, the compression ratio was measured. Specifically, the sub-pad was cut to a width of 5 cm and a length of 5 cm, and a thickness (A) was measured after placing an 85 g weight on it for 30 seconds using a Dial Thickness Gauge (129-E, YASUDA), and a thickness (B) was measured after placing an additional 800 g weight (85 g weight + 800 g weight) on it for 3 minutes, and the compression ratio was calculated according to the following Equation 3.

[0179] [Mathematical Formula 3]

[0180] Compression ratio (%) = [(A - B) / A] × 100

[0181]

[0182] Experimental Example 3: Density

[0183] For the subpads prepared in Example 1, Comparative Example 1, and Comparative Example 2 above, the density was measured according to ASTM D1622.

[0184]

[0185] Experimental Example 4: Compressive modulus

[0186] The elasticity of the sub-pads prepared in Example 1, Comparative Example 1, and Comparative Example 2 above was measured. Specifically, the sub-pad was cut to a width of 5 cm and a length of 5 cm, and a thickness (A) was measured after placing an 85 g weight on it for 30 seconds using a dial thickness gauge (model name: 129-E, manufacturer: YASUDA), and a thickness (C) was measured after placing an additional 800 g weight (85 g weight + 800 g weight) on it for 3 minutes, then removing the 800 g weight and leaving it for 1 minute, and the compressive elasticity modulus was calculated according to the following Equation 4.

[0187] [Mathematical Formula 4]

[0188] Compressive modulus (%) = [C / A] × 100

[0189]

[0190] Classification Example 1 Comparative Example 1 Comparative Example 2 Subpad Thickness (mm) 1.1 1.1 1.1 Hardness (Shore A) 6 6.7 7 6.4 7 2.3 Compression Ratio (%) 8.4 9.1 8.8 Density (g / cm³) 3 Compressive modulus (%) 79.39 2.386

[0191] As a result, the subpad of Example 1 showed higher hardness (Shore D), compression ratio (%), and density (g / cm³) compared to the subpads of Comparative Examples 1 and 2. 3 It was confirmed that the required physical properties of the sub-pad layer were excellent in terms of ) and compressive elasticity (%).

[0192]

[0193] Biomass Content

[0194] Experimental Example 5: Biomass content of the sub-pad

[0195] Based on ASTM D 6866 standards (applying radiocarbon dating methods), the biomass (biocarbon) content (sample size: width: 5 cm, length: 5 cm) contained in the subpads of Example 1 and Comparative Examples 1 and 2 was analyzed, and the results are shown in Table 2 below.

[0196]

[0197] Biomass Content Example 1 Comparative Example 1 Comparative Example 2 Based on total weight of sub-pad 17 wt% 0 wt% 0 wt%

[0198] As a result, it was confirmed that the sub-pad layer of Example 1 had a higher biomass content compared to the sub-pad layers of Comparative Examples 1 and 2.

[0199] In conclusion, the sub-pad layer of the polishing pad according to the present invention has a high biomass content while maintaining hardness (Shore D), compressibility (%), and density (g / cm³). 3 It was confirmed that the material has excellent properties in terms of ) and compressive modulus (%), and that the polishing rate is evenly distributed according to the distance from the center in the CMP process polishing profile, thereby improving polishing flatness.

[0200]

[0201] [Explanation of the symbol]

[0202] 10: Top pad layer, 20: Adhesive layer, 30: Sub pad layer,

[0203] 100: Polishing pad, 200: Platen, 300: Conditioner,

[0204] 400: Grinding slurry, 510: Grinding head, 520: Carrier,

[0205] 600: Semiconductor substrate (wafer).

Claims

1. Top pad layer; and It includes a sub-pad layer prepared from a biomass-containing composition, and The above sub-pad layer is an abrasive pad having a total biomass content of 15% to 20% by weight as measured by ASTM D 6866.

2. In Paragraph 1, The above biomass-containing composition includes a urethane prepolymer, and A polishing pad in which the above urethane prepolymer is manufactured from a urethane prepolymer composition comprising an isocyanate raw material and a polyol raw material.

3. In Paragraph 2, A polishing pad comprising the above isocyanate raw material; and the above polyol raw material comprising biomass.

4. In Paragraph 2, A polishing pad comprising one or more types selected from the group consisting of bio-based polymer polyols and bio-based monomer polyols, wherein the above polyol raw material comprises 5. In Paragraph 4, A polishing pad comprising one or more types selected from the group consisting of bio-based polymer polyols, bio-based polyether polyols, bio-based polyester polyols, bio-based polycarbonate polyols, and bio-based polycaprolactam polyols.

6. In Paragraph 4, A polishing pad comprising one or more selected from the group consisting of bio-based monomer polyols: bio-based ethylene glycol, bio-based diethylene glycol, bio-based 1,2-propylene glycol, bio-based 1,3-propanediol, bio-based 2-methyl-1,3-propanediol, bio-based 1,3-butanediol, bio-based 1,4-butanediol, bio-based 2,3-butanediol, bio-based n-butanol, bio-based isobutanol, bio-based 1,5-pentanediol, bio-based 2-octanol, bio-based 1,9-nonanediol, bio-based 1,10-decanediol, bio-based diethylene glycol, and bio-based isosorbide.

7. In Paragraph 2, A polishing pad in which the above isocyanate raw material comprises a bio-based isocyanate.

8. In Paragraph 7, A polishing pad comprising one or more types selected from the group consisting of bio-based isocyanates, bio-based toluene diisocyanate, and bio-based 4,4'-methylene dicyclohexyl diisocyanate.

9. A step of preparing a biomass-containing urethane prepolymer from a urethane prepolymer composition comprising an isocyanate raw material and a polyol raw material comprising a bio-based polyol; A step of preparing a biomass-containing composition comprising the above-mentioned biomass-containing urethane prepolymer, a curing agent, and a foaming agent; A step of manufacturing a sub-pad layer by curing the above biomass-containing composition; The method includes the step of attaching the above sub-pad layer to the top pad layer, A method for manufacturing a polishing pad, wherein the above sub-pad layer has a total biomass content of 15% to 20% by weight as measured by ASTM D 6866.

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