Polishing slurry, method of manufacturing semiconductor device, and micelle of branched polymer

Abstract

Disclosed are polishing slurries, methods of manufacturing semiconductor devices, and micelles of branched polymers, the polishing slurries comprising: a branched polymer comprising hydrophobic units, micelles of the branched polymer, or a combination thereof, and a dispersion medium.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2025-0021103, filed with the Korean Intellectual Property Office on February 18, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The polishing slurry and the method for manufacturing semiconductor devices are disclosed. Background Technology

[0004] Consistent with the miniaturization of electronic devices and the resulting miniaturization of integrated circuits, various methods have been studied for forming microstructures with widths of several nanometers, such as metal lines, contact holes, or shallow trench isolation.

[0005] When forming such microstructures, polishing processes can be performed to make the surface of the microstructures flat and smooth, and chemical mechanical polishing (CMP) is one such polishing process. Chemical mechanical polishing is a process of polishing the object to be polished by providing a polishing slurry. Summary of the Invention

[0006] To improve the performance of chemical mechanical polishing, it is necessary to ensure a high polishing rate for the object to be polished, such as a metal layer, while also improving the polishing selectivity relative to adjacent layers, reducing defects such as scratches, and preventing damage caused by particulate residues.

[0007] One embodiment provides a polishing slurry capable of improving polishing selectivity relative to adjacent layers, reducing defects such as scratches, and preventing damage caused by particulate residues.

[0008] Another embodiment provides a method for manufacturing semiconductor devices that can improve polishing selectivity relative to adjacent layers, reduce defects such as scratches, and prevent damage caused by particulate residues.

[0009] According to one embodiment, the polishing slurry comprises: a branched polymer including hydrophobic units, micelles of the branched polymer, or a combination thereof, and a dispersion medium.

[0010] The hydrophobic unit may include substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C3-C30 cycloalkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C6-C30 aromatic group, substituted or unsubstituted siloxane group, or combinations thereof.

[0011] The branched polymer may further include hydrophilic functional groups located at the ends of the branched polymer, and the hydrophilic functional groups may include hydroxyl, sulfonate (sulfonate) groups, carboxylate (carboxylate) groups, phosphonate (phosphonate) groups, ammonium groups, pyrrolidine groups, etc. group, imidazole Groups, amino groups, amide groups, aldehyde groups, ketone groups, epoxy (epoxide) groups, or combinations thereof.

[0012] The branched polymer may include structural units derived from glycerol, ethylene glycol, propylene glycol, ethyleneimine, piperazine, trimethylolpropane, sorbitol, acrylic acid, methacrylic acid, their derivatives, or combinations thereof.

[0013] The branched polymer may include 2 to 100 structural units.

[0014] The branched polymer may include structural units represented by chemical formula A (also known as repeating units or repeating structural units) and terminal portions represented by chemical formula B.

[0015] [Chemical Formula A] [Chemical Formula B]

[0016]

[0017] In chemical formulas A and B,

[0018] X 1 and X 2 Each can be an independent hydrogen or hydrophilic functional group, and

[0019] *This can be a connection point with an adjacent structural unit.

[0020] X of chemical formula B 1 and X 2 Each group can be independently composed of hydrogen, sulfonate, carboxylate, phosphonate, ammonium, or pyrrolidine groups. group, imidazole Groups, amino groups, amide groups, aldehyde groups, ketone groups, epoxy groups, or combinations thereof.

[0021] In the branched polymer, the hydrophobic unit is the starting portion of the branched polymer, and the structural unit represented by chemical formula A is located between the hydrophobic unit and the terminal portion represented by chemical formula B.

[0022] The weight-average molecular weight of the branched polymer can be from about 300 to about 5,000.

[0023] The micelles may be in the form of assemblies or aggregates of multiple branched polymers, and the micelles may include: a core in which the hydrophobic units are assembled, and a shell comprising polymer segments including hydrophilic functional groups and structural units (also referred to as repeating units or repeating structural units) derived from glycerol, ethylene glycol, propylene glycol, ethyleneimine, piperazine, trimethylolpropane, sorbitol, acrylic acid, methacrylic acid, their derivatives, or combinations thereof. The polymer segments may be derived from glycerol, ethylene glycol, propylene glycol, ethyleneimine, piperazine, trimethylolpropane, sorbitol, acrylic acid, methacrylic acid, their derivatives, or combinations thereof. The hydrophilic functional groups may be located at the ends of the polymer segments. A portion of the polymer segment other than the hydrophilic functional groups may be located between the hydrophobic units and the hydrophilic functional groups.

[0024] The particle size of the micelles, as measured by dynamic light scattering in an aqueous (water-containing) medium, can be from about 1 nm to about 50 nm.

[0025] Based on the total amount of the polishing slurry, the branched polymer, the micelles, or a combination thereof may be included in an amount of about 0.1% to about 30% by weight.

[0026] The polishing slurry may further include an oxidant and may not include inorganic abrasives.

[0027] According to another embodiment, a method of manufacturing a semiconductor device includes: forming a conductive layer (e.g., a metal layer) on a dielectric layer having trenches, supplying a polishing slurry onto the conductive layer (e.g., the metal layer), and chemically and mechanically polishing the conductive layer (e.g., the metal layer) to form a conductive pattern (e.g., a metal pattern) embedded in the trenches, wherein the polishing slurry comprises: a branched polymer including hydrophobic units, micelles of the branched polymer, or a combination thereof, and a dispersion medium.

[0028] The hydrophobic unit may include substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C3-C30 cycloalkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C6-C30 aromatic, substituted or unsubstituted siloxane groups, or combinations thereof, and the branched polymer may further include structural units derived from glycerol, ethylene glycol, propylene glycol, ethyleneimine, piperazine, trimethylolpropane, sorbitol, acrylic acid, methacrylic acid, their derivatives, or combinations thereof, and units including hydroxyl, sulfonate, carboxylate, phosphonate, ammonium, and pyrrolidine groups. group, imidazole Hydrophilic functional groups, including groups, amino groups, amide groups, aldehyde groups, ketone groups, epoxy groups, or combinations thereof.

[0029] The branched polymer may include structural units represented by chemical formula A and terminal portions represented by chemical formula B.

[0030] Based on the total amount of the polishing slurry, the branched polymer or micelles of the branched polymer may be included in an amount from about 0.1% to about 30% by weight, and the temperature of the polishing slurry during the chemical mechanical polishing may be from room temperature to about 70°C.

[0031] The micelles may be in the form of assemblies or aggregates of the branched polymers, and each micelle may include: a core in which the hydrophobic unit is assembled, and a shell comprising structural units and hydrophilic functional groups derived from glycerol, ethylene glycol, propylene glycol, ethyleneimine, piperazine, trimethylolpropane, sorbitol, acrylic acid, methacrylic acid, their derivatives, or combinations thereof.

[0032] The particle size of the micelles, measured by dynamic light scattering in an aqueous medium, can be from about 1 nm to about 50 nm.

[0033] According to another embodiment, the micelles of the branched polymer comprise: a core in which hydrophobic units are assembled, and a shell comprising polymer segments including (a plurality of) hydrophilic functional groups and structural units derived from (derived from) glycerol, ethylene glycol, propylene glycol, ethyleneimine, piperazine, trimethylolpropane, sorbitol, acrylic acid, methacrylic acid, derivatives thereof, or combinations thereof, and the particle size of the micelles, measured by dynamic light scattering in an aqueous medium, is from about 1 nm to about 50 nm.

[0034] It will be understood that the description herein of branched polymers in polishing slurries and / or micelles of said branched polymers may also be applied to methods for manufacturing semiconductor devices and micelles of branched polymers.

[0035] The polishing slurry, the method of manufacturing semiconductor devices, and the micelles of the branched polymer can effectively reduce defects such as scratches and prevent damage caused by particulate residues while improving polishing selectivity. Attached Figure Description

[0036] Figure 1 This is a schematic diagram illustrating an example of a branched polymer and its micelles according to an embodiment.

[0037] Figures 2 to 5 This is a cross-sectional view illustrating an example of a method for manufacturing a semiconductor device according to an embodiment.

[0038] Figure 6This is a schematic diagram showing a chemical mechanical polishing apparatus according to an embodiment.

[0039] Figure 7A The image shows a SEM image of the surface of the polished product obtained by chemical mechanical polishing according to Example 4.

[0040] Figure 7B This is a SEM image of the cross-section of the polished product obtained by chemical mechanical polishing according to Example 4.

[0041] Figure 7C The image shows a SEM image of the surface of the polished product obtained by chemical mechanical polishing according to Example 1.

[0042] Figure 8A SEM images of the surface of the polished product obtained by chemical mechanical polishing according to Reference Example 1, and

[0043] Figure 8B The image shows a cross-sectional SEM image of the polished product obtained by chemical mechanical polishing according to Reference Example 1. Detailed Implementation

[0044] Example implementations will be described in detail below and can be readily performed by those skilled in the art. However, this disclosure may be implemented in many different forms and is not to be construed as limited to the exemplary implementations set forth herein.

[0045] In the accompanying drawings, for clarity, the thickness of layers, films, panels, regions, etc., is exaggerated. The same reference numerals denote the same elements throughout the specification. It will be understood that when an element, such as a layer, film, region, or substrate, is referred to as being "on" another element, it may be directly on said other element, or there may be intermediate elements present. Conversely, when an element is referred to as being "directly on" another element, there are no intermediate elements present.

[0046] As used herein, unless otherwise defined, “substituted” means that the hydrogen atom of a compound or group is replaced by a substituent selected from the following: halogen atom, hydroxyl, nitro, cyano, amino, azide, amido, hydrazine, hydrazone, C2 to C20 acyl, carbamoyl, thiol, ester group, carboxyl or a salt thereof, sulfonic acid or a salt thereof, phosphate or a salt thereof, silyl, C1 to C20 alkyl, C2 to C20 alkenyl, C2 to C20 alkynyl, C6 to C30 aryl, C7 to C30 arylalkyl, C1 to C30 alkoxy, C1 to C20 heteroalkyl, C3 to C20 heteroaryl, C3 to C20 heteroarylalkyl, C3 to C30 cycloalkyl, C3 to C15 cycloalkenyl, C6 to C15 cycloalkynyl, C3 to C30 heterocycloalkyl, and combinations thereof.

[0047] As used herein, unless otherwise defined, “heterogeneous” means one to four heteroatoms selected from N, O, S, Se, Te, Si, and P.

[0048] In this article, the unit of molecular weight is g / mol.

[0049] In the following text, the term "combination" includes mixtures or stacked structures of two or more.

[0050] The polishing slurry according to the embodiments is described below.

[0051] Polishing slurries can be used in semiconductor device manufacturing processes to planarize solid surfaces or remove steps on solid surfaces by being applied to the surface of the object to be polished (dielectric or conductive layer).

[0052] The polishing slurry according to embodiments includes a branched polymer, micelles of the branched polymer, or a combination thereof, and a dispersion medium. Hereinafter, when the terms "branched polymer" and "mice of a branched polymer" are mentioned together, the term "branched polymer" refers to a branched polymer that has not formed micelles.

[0053] The branched polymer may be a macromolecule in which side chains extend regularly or irregularly (regularly or randomly) from the main chain of the polymer, and may have multiple branching points, with two or more chains connected at said branching points.

[0054] The branched polymer may include: polymer segments in which repeating structural units (repeating units) of the polymer are distributed, and hydrophobic units bonded to the polymer segments, wherein the polymer segments include hydrophilic functional groups located at their ends. A portion of the polymer segment other than the hydrophilic functional groups may be located between the hydrophobic units and the hydrophilic functional groups. One polymer segment may correspond to one hydrophobic unit and two or more hydrophilic functional groups.

[0055] The polymer chain segment may include branch points and multiple structural units connected to the branch points, and each structural unit may be connected to other branch points and extend in one or more directions to form a three-dimensional structure without cross-linking.

[0056] The polymer segments can determine the size of the branched polymer and can be formed into a hyperbranched polymer occupying the desired extended space by controlling, for example, the number of branch points and structural units and / or the degree of branching (DB) in the polymer segments.

[0057] The branched polymers disclosed herein may be hyperbranched polymers.

[0058] The number of repeating structural units in the hyperbranched polymer may be, for example, two or more, and may be, for example, two to 100, three to 50, four to 30, five to 20, or six to 10.

[0059] The degree of branching of a branched polymer can be calculated by the ratio between the linear (linear) structure and the branched structure of the polymer, and can be calculated, for example, by Equation 1.

[0060] [Equation 1]

[0061] Branching degree (DB) = (D + T) / (D + T + L)

[0062] In Equation 1, D represents a dendritic cell originating from a branch point, T represents a terminal cell, and L represents a linear cell.

[0063] The D, T, and L values ​​can be obtained by distinguishing the signal of each structure using nuclear magnetic resonance spectroscopy (NMR) and integrating it. The closer the branching degree (DB) is to 0, the closer it is to a linear structure, and when the branching degree (DB) is 1, it can mean a fully branched structure.

[0064] Typically, the degree of branching in hyperbranched polymers ranges from about 0.2 to about 1.0. Branching reactions in branched polymers can occur randomly, and therefore, the number and / or degree of branching of branching points and structural units (repeating units) in the polymer chain segments can vary. These characteristics lead to structural diversity in branched polymers, which can affect the physical and chemical properties of the final material (branched polymer).

[0065] Branched polymers can possess the following properties. First, branched polymers include abundant reactive functional groups at the branching terminal groups, which facilitates various chemical modifications and functionalizations. This allows branched polymers to play an important role in a wide range of applications, such as drug delivery, catalyst design, coatings, and polymer composites. Second, compared to linear polymers with the same weight-average molecular weight, they can exhibit relatively low solution viscosity, which is advantageous in the mixing and processing of polymer solutions, and this low viscosity enables cost-effective batch processing. Third, branched polymers can be endowed with properties tailored to specific application purposes through the diversity of branching structures and design flexibility, and can be, for example, tuned to be designed as biocompatible materials or for improving heat resistance and mechanical strength.

[0066] The polymer segments can be obtained by polymerization of reactants (monomers) having reactive sites such as -OH, -NH- and / or -NH2, and may include structural units (repeating units) derived from (obtained from), for example, glycerol, ethylene glycol, propylene glycol, ethyleneimine, piperazine, trimethylolpropane, sorbitol, acrylic acid, methacrylic acid, their derivatives, or combinations thereof. In this document, the term "derivative" means (1) a substituted compound or substituted group in which at least one hydrogen atom of a compound or group is replaced by a substituent, or (2) a compound or group obtained by removing one or more small molecules (e.g., H2O) from a compound or group (e.g., by condensation reaction). The substituents are as defined above.

[0067] The monomers used to form these polymer segments can be classified into various types depending on their structure and reactivity. For example, AB2-type monomers include one A-type functional group and two B-type functional groups, and can form branched structures through selective reactions between A and B. For example, A2B3-type monomers can form more highly branched and complex three-dimensional structures by including two A-type functional groups and three B-type functional groups. For example, AB... x Type monomers (x≥3) may include one A functional group and three or more B functional groups, and as the value of x increases, the branching degree and complexity of the polymer may increase, and for example, they may include polyfunctional alcohols such as glycerol.

[0068] For example, glycidyl ether, as a derivative of glycerol, can possess the characteristics of AB2-type monomers, and glycidyl ether can form branched structures through ring-opening polymerization (ROP), and can be efficiently polymerized, for example, through anionic ring-opening multibranching polymerization. In this process, the epoxy ring of glycidyl ether can exhibit high reactivity and simultaneously act on the branching and growth processes. Glycidyl ether can be used in this paper in the manufacture of branched polymers such as hyperbranched polyether polyols.

[0069] For example, epoxide monomers such as ethylene oxide or propylene oxide (e.g., as derivatives of ethylene glycol or propylene glycol) can be used to synthesize branched polyethers, and such epoxide monomers can be used as important building blocks for designing polymer materials suitable for specific applications by introducing functional terminal groups or by structural control.

[0070] These monomers are used to design and synthesize multi-branched polymers suitable for specific applications by utilizing their respective reactive functional groups and the ability to form branched structures.

[0071] The hydrophobic unit may be a portion having hydrophobic properties. The hydrophobic unit may be derived from (e.g., from) an initiator used for the polymerization of branched polymers, and may be a portion of said initiator other than the reactive site (e.g., -OH, -NH-, and / or -NH2) (e.g., a hydrocarbon moiety). The hydrophobic unit may include, but is not limited to, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C3-C30 cycloalkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C6-C30 aromatic groups, substituted or unsubstituted siloxane groups, or combinations thereof.

[0072] The hydrophobic unit can be bonded to the starting point of the polymer segment and can be located on the opposite side of the hydrophilic functional group described below, with the portion of the polymer segment other than the hydrophilic functional group in between. For example, when the initiator has one reaction site, the reaction by the initiator occurs in one direction, and therefore the branched polymer can include a polymer segment bonded to one side of the hydrophobic unit. For example, when two reaction sites of the initiator are present, the reaction by the initiator occurs in two directions, and therefore the branched polymer can include polymer segments bonded to both sides of the hydrophobic unit. For example, when the initiator has three reaction sites, the reaction by the initiator occurs in three directions, and therefore the branched polymer can include polymer segments bonded to the hydrophobic unit in three directions. Thus, the size and structure of the branched polymer can be controlled depending on the type of initiator.

[0073] The hydrophilic functional group may be located at the end of the polymer chain segment. The hydrophilic functional group may include anionic, cationic, nonionic functional groups, or combinations thereof, and may include hydroxyl, sulfonate, carboxylate, phosphonate, ammonium, and pyrrolidine groups. group, imidazole Groups, amino groups, amide groups, aldehyde groups, ketone groups, or combinations thereof, but not limited to these.

[0074] For example, the branched polymer may be a branched polyglycerol derivative (a branched polymer of a glycerol derivative) having a structural unit (repeating unit) derived from glycerol, and the branched polyglycerol derivative may include, for example, a structural unit represented by chemical formula A and a terminal portion represented by chemical formula B.

[0075] [Chemical Formula A] [Chemical Formula B]

[0076]

[0077] In chemical formulas A and B,

[0078] X 1 and X2 Each of these can be an independent hydrogen or hydrophilic functional group, and the hydrophilic functional group can be, for example, a sulfonate group, a carboxylate group, a phosphonate group, an ammonium group, or a pyrrolidine group. group, imidazole Groups, amino groups, amide groups, aldehyde groups, ketone groups, epoxy groups, or combinations thereof, and

[0079] *This can be a connection point with an adjacent structural unit.

[0080] The structural unit represented by chemical formula A can be obtained from glycidol.

[0081] For example, branched polyglycerol derivatives can be represented by the chemical formula C, but are not limited thereto.

[0082] [Chemical formula C]

[0083]

[0084] In chemical formula C,

[0085] HB can be a hydrophobic unit, such as a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C2-C30 alkenyl group, a substituted or unsubstituted C3-C30 cycloalkenyl group, a substituted or unsubstituted C2-C30 alkynyl group, a substituted or unsubstituted C6-C30 aromatic group, a substituted or unsubstituted siloxane group, or a combination thereof.

[0086] PS can be polymer segments including hydrophilic functional groups.

[0087] L can be a linking group between the hydrophobic unit and the polymer segment, such as a single bond, a substituted or unsubstituted C1-C10 alkylene group, or a substituted or unsubstituted C1-C10 oxyalkylene group.

[0088] n can be an integer from 1 to 5, such as 1 to 4, 1 to 3, or 1 to 2.

[0089] In branched polyglycerol derivatives represented by chemical formula C, the polymer segment (PS) may be represented by, for example, chemical formula D, but is not limited thereto.

[0090] [Chemical formula D]

[0091]

[0092] In chemical formula D,

[0093] X 1 and X 2 Each of these functional groups can be independently hydrogen or hydrophilic, and the hydrophilic functional group can be, for example, a sulfonate group, a carboxylate group, a phosphonate group, an ammonium group, or a pyrrolidine group. group, imidazole Groups, amino groups, amide groups, aldehyde groups, ketone groups, epoxy groups, or combinations thereof, and

[0094] * can be the connection point with L.

[0095] In chemical formula D, an example of a branched polymer represented by chemical formula A is illustrated, which includes structural units that extend and connect to multiple branch points. However, the number of branch points and structural units (repeating units) can vary and is not limited to the above structure.

[0096] The number-average molecular weight of the branched polymer can be, for example, about 200 to about 10,000, about 300 to about 9,000, about 400 to about 8,000, about 500 to about 7,000, about 600 to about 6,000, about 700 to about 5,000, about 800 to about 4,000, or about 900 to about 3,000. The weight-average molecular weight of the branched polymer can be, for example, about 200 to about 10,000, for example, about 300 to about 9,000, about 400 to about 8,000, about 500 to about 7,000, about 600 to about 6,000, about 700 to about 5,000, about 800 to about 4,000, about 900 to about 3,000, or about 1,000 to about 2,000. Here, number-average molecular weight and weight-average molecular weight can be analyzed by gel permeation chromatography (GPC) at approximately 25°C using dimethylformamide (DMF) as the mobile phase at a flow rate of approximately 1.0 mL / min. GPC analysis can be performed using an Agilent 1200 series system, and calculations can be based on polyethylene glycol (PEG) standards.

[0097] Branched polymers can be amphiphilic polymers comprising hydrophobic units and hydrophilic functional groups, and therefore micelles can be formed through the spontaneous self-assembly of the hydrophobic units of adjacent branched polymers in the dispersion medium. The dispersion medium can be water, such as deionized water, and the micelles can be colloidal nanoparticles.

[0098] Figure 1 This is a schematic diagram illustrating an example of a branched polymer and its micelles according to an embodiment.

[0099] Reference Figure 1 Micelles 250 may be three-dimensional nanoparticles self-assembled from multiple branched polymers 200, and may be colloidal nanoparticles dispersed in a dispersion medium (e.g., water). Micelles 250 include a core 260 and a shell 270, with hydrophobic units 210 of adjacent branched polymers 200 assembled and arranged in the core 260. The shell 270 includes polymer segments 220, which comprise structural units and hydrophilic functional groups and are arranged close to the dispersion medium. The hydrophilic functional groups may be arranged on the outermost surface of the shell 260.

[0100] Micelles 250 may be included in the polishing slurry in the form of colloidal nanoparticles, and the particle size of the micelles, as measured by dynamic light scattering (DLS) in an aqueous medium, may be less than or equal to about 50 nm, and may be about 1 nm to about 50 nm, about 1 nm to about 40 nm, about 1 nm to about 30 nm, about 1 nm to about 20 nm, about 2 nm to about 50 nm, about 2 nm to about 40 nm, about 2 nm to about 30 nm, about 2 nm to about 20 nm, about 3 nm to about 16 nm, about 4 nm to about 12 nm, about 5 nm to about 10 nm, or about 5 nm to about 8 nm.

[0101] For example, when a branched polymer is present in a dispersion medium (e.g., water) at a concentration greater than or equal to a predetermined concentration, micelles can be formed. For example, based on the total amount of the polishing slurry, a branched polymer may be included in an amount greater than or equal to about 0.1 wt%, and within the above range, a branched polymer may be included in an amount from about 0.1 wt% to 30 wt%. That is, based on the total amount of the polishing slurry, the polishing slurry may include about 0.1 wt% to about 30 wt% of a branched polymer, its micelles, or a combination thereof. The amount may be, for example, about 0.2 wt% to about 28 wt%, about 0.3 wt% to about 25 wt%, about 0.4 wt% to about 20 wt%, about 0.5 wt% to about 10 wt%, about 0.6 wt% to about 5 wt%, about 0.8 wt% to about 3 wt%, or about 1 wt% to about 2 wt%.

[0102] For example, branched polymers can form micelles within a predetermined temperature range. For instance, branched polymers in polishing slurries can form micelles at temperatures from room temperature to less than or equal to about 70°C, for example, from room temperature to less than or equal to about 50°C, or from room temperature to less than or equal to about 30°C.

[0103] For example, branched polymers can form micelles within a predetermined pH range, such as at pH 2 to 10, for example 2 to 8, 2 to 6, or 2 to 4.

[0104] As described above, by controlling the number and / or degree of branching of branch points and structural units (repeating units), branched polymers can be formed into hyperbranched polymers occupying space extended to a desired extent. Furthermore, the size and structure of hyperbranched polymers can be effectively controlled depending on the type of initiator (e.g., the number of reaction sites), and the properties of branched polymers can be controlled depending on the type and number of hydrophilic functional groups. Additionally, due to the inclusion of hydrophobic units and hydrophilic functional groups described above, branched polymers can form micelles in a dispersion medium (e.g., water), and such micelles can exist in the form of colloidal nanoparticles to provide enhanced physical forces to the polishing slurry.

[0105] Therefore, polishing slurries comprising branched polymers and / or their micelles can be applied to a solid surface covered with polishing material to effectively remove the polishing material, and chemical mechanical polishing (CMP) can be performed without inorganic abrasives such as silica, cerium dioxide, alumina, zirconium oxide, titanium dioxide, silicon nitride, SiC, or diamond.

[0106] For example, polishing slurries can be abrasive-free slurries, thereby effectively reducing or preventing defects such as scratches caused by inorganic abrasives and / or damage caused by inorganic abrasive residues. However, this disclosure is not limited thereto, and polishing slurries do not exclude the further inclusion of inorganic abrasives.

[0107] In addition, branched polymers and / or their micelles can selectively polish desired membrane materials by functionalizing them with various functional groups, thereby effectively controlling the polishing selectivity between membrane materials that are to be removed and those that are not.

[0108] The polishing slurry may further include an oxidizing agent. The oxidizing agent oxidizes the object to be polished, and, for example, when the polishing slurry is applied to an object comprising a metal or semi-metal, the surface of the object to be polished may be oxidized to form a metal oxide or semi-metal oxide. The object to be polished oxidized by the oxidizing agent (e.g., a metal oxide or semi-metal oxide) may have relatively lower hardness or brittleness than the metal or semi-metal, and may be effectively removed by branched polymers and / or their micelles due to the difference in mechanical strength between the object to be polished and the oxidized object to be polished.

[0109] There are no restrictions on the oxidizing agent, as long as it can oxidize the object to be polished, and it may include, for example, hydrogen peroxide, peracetic acid, percarbonate, urea peroxide, perchloric acid, persulfate, ferric nitrate (III), their hydrates, or combinations thereof.

[0110] Based on the polishing slurry, the amount of oxidant may be less than or equal to about 5% by weight, and within that range from about 0.001% by weight to about 5% by weight, from about 0.001% by weight to about 4% by weight, from about 0.001% by weight to about 3% by weight, from about 0.001% by weight to about 2% by weight, from about 0.001% by weight to about 1% by weight, or from about 0.001% by weight to about 0.5% by weight.

[0111] Polishing slurries may further include additives such as chelating agents (oxidation regulators), surfactants, dispersants, pH adjusters, polishing inhibitors, or combinations thereof.

[0112] Chelating agents (oxidation regulators) may be phosphoric acid, nitric acid, citric acid, malonic acid, their salts, or combinations thereof, but are not limited thereto.

[0113] The surfactant may be an ionic or nonionic surfactant, and may be, for example, a copolymer of ethylene oxide, a copolymer of propylene oxide, an amine compound, or a combination thereof, but is not limited thereto.

[0114] pH adjusters can adjust the pH of polishing slurries and can be, for example, inorganic acids or their salts, inorganic bases, organic acids or their salts, or combinations thereof. Inorganic acids or their salts may include nitric acid, hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, hydrobromic acid, iodic acid, or their salts; inorganic bases may include potassium hydroxide, sodium hydroxide, or ammonium hydroxide; and organic acids or their salts may include formic acid, malonic acid, maleic acid, oxalic acid, adipic acid, citric acid, acetic acid, propionic acid, fumaric acid, lactic acid, salicylic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutamic acid, glycolic acid, lactic acid, aspartic acid, tartaric acid, or their salts, but the embodiments are not limited thereto.

[0115] Each component of the additive may be included independently in trace amounts, such as from about 1 ppm to about 100,000 ppm, but is not limited thereto.

[0116] The polishing slurry may further include a dispersion medium capable of dissolving and / or dispersing the components described above, and the dispersion medium may be, for example, water. Water may be, for example, distilled water and / or deionized water. The dispersion medium may be included as a balance excluding solids such as branched polymers, micelles of branched polymers, oxidants, and various additives.

[0117] The pH of the polishing slurry can be from about 2.0 to about 12.0, and within the above range it can be from about 2.0 to about 10.0, from about 2.0 to about 8.0, from about 2.0 to about 6.0, or from about 2.0 to about 4.0.

[0118] The polishing slurry can be applied to the formation of various structures. For example, it can be used in the polishing process of conductive layers such as metal lines or dielectric layers such as shallow trench isolation (STI) or insulating films. For instance, the polishing slurry can be used to polish conductive layers such as metal lines in a semiconductor substrate, or it can be used to polish metal layers such as tungsten (W) or tungsten alloys.

[0119] The following describes an example of a method for manufacturing semiconductor devices using the polishing slurry.

[0120] Methods for manufacturing semiconductor devices according to some example embodiments include chemical mechanical polishing (CMP) of the surface of an object to be polished.

[0121] The object to be polished can be of a wide variety of structures, such as a semiconductor substrate, such as a silicon wafer (including thin films such as dielectric layers or metal layers), and the polishing surface can include metals such as tungsten, molybdenum, aluminum, copper or nickel, their alloys, or metal oxides or half-metal oxides produced during a chemical mechanical polishing process; oxides such as silicon oxide, aluminum oxide, titanium oxide, gallium oxide, tungsten oxide, or molybdenum oxide; nitrides such as silicon nitride, aluminum nitride, titanium nitride, or gallium nitride; carbides such as silicon carbide; elemental semiconductors such as silicon or germanium; compound semiconductors such as InP, GaAs; organic or inorganic compounds such as tetraethyl orthosilicate (TEOS); or combinations thereof.

[0122] For example, the polishing slurry can be used to polish conductive layers, such as metal lines, within a semiconductor substrate, and can be used to form conductive patterns (e.g., conductive lines) from conductive layers comprising, for example, tungsten (W) or alloys thereof. The conductive patterns can be embedded in trenches of the dielectric layer.

[0123] The following describes examples of methods for manufacturing semiconductor devices using the polishing slurry.

[0124] Figures 2 to 5 This is a cross-sectional view illustrating an example of a method for manufacturing a semiconductor device according to some exemplary embodiments.

[0125] Reference Figure 2 A dielectric layer 20 is formed on a semiconductor substrate 10. The dielectric layer 20 may include oxides, nitrides, and / or oxynitrides. The dielectric layer 20 is then etched to form a trench 20a. The width of the trench 20a may be less than about 50 nm, and within the above range, may be greater than or equal to about 1 nm and less than about 50 nm, about 1 nm to about 40 nm, about 1 nm to about 30 nm, about 1 nm to about 20 nm, about 1 nm to about 15 nm, about 1 nm to about 10 nm, or about 1 nm to about 8 nm. A barrier layer 30 is then formed on the sidewalls of the trench 20a. The barrier layer 30 may include, for example, Ti, Ta, TiN, and / or TaN, but is not limited thereto.

[0126] Reference Figure 3 A conductive layer 40 is formed inside and on the trench 20a. The conductive layer 40 may include, for example, tungsten, molybdenum, aluminum, copper, nickel, alloys thereof, or combinations thereof.

[0127] Reference Figure 4 The surface of the conductive layer 40 is planarized to substantially match the surface of the dielectric layer 20 to form an embedded conductive pattern 40a. Planarization can be performed by chemical mechanical polishing using a chemical mechanical polishing apparatus, and a polishing slurry can be used. This will be described later.

[0128] For example, when the conductive layer 40 is a tungsten-containing layer, the removal rate (RR) of the tungsten-containing wires in the polishing slurry can be greater than or equal to about 300 Å / min, and within the above range can be about 300 Å / min to about 5,000 Å / min, about 400 Å / min to about 5,000 Å / min, about 500 Å / min to about 5,000 Å / min, about 600 Å / min to about 5,000 Å / min, about 700 Å / min to about 5,000 Å / min, about 800 Å / min to about 5,000 Å / min, about 800 Å / min to about 4,000 Å / min, about 800 Å / min to about 3,000 Å / min, about 800 Å / min to about 2,000 Å / min, about 800 Å / min to about 1,500 Å / min, or about 800 Å / min. From Å / min to approximately 1,200 Å / min.

[0129] Polishing slurries can exhibit high polishing selectivity between conductive materials such as metals and dielectric materials such as oxides, and therefore can effectively polish conductive layers such as metals at high polishing rates while minimizing loss or damage to the dielectric layer. For example, when dielectric layer 20 is an oxide layer (e.g., silicon oxide layer) and conductive layer 40 is a tungsten-containing layer (e.g., tungsten layer), the higher the ratio of the polishing rate of tungsten to the polishing rate of oxide (e.g., silicon oxide) in the polishing slurry, i.e., the higher the polishing selectivity, the better.

[0130] For example, the polishing selectivity may be higher than about 200:1, and within the above range, the polishing selectivity may be higher than about 300:1, higher than about 400:1, higher than about 500:1, higher than about 600:1, higher than about 700:1, higher than about 800:1, and within the above range, it may be higher than about 200:1 and lower than about 5000:1, higher than about 300:1 and lower than about 5000:1, higher than about 400:1 and lower than about 5000:1, higher than about 5000:1, and higher than about 5000:1. :1 and below approximately 5000:1, above approximately 600:1 and below approximately 5000:1, above approximately 700:1 and below approximately 5000:1, above approximately 800:1 and below approximately 5000:1, above approximately 800:1 and below approximately 4000:1, above approximately 800:1 and below approximately 3000:1, above approximately 800:1 and below approximately 2000:1, above approximately 800:1 and below approximately 1500:1, or above approximately 800:1 and below approximately 1200:1.

[0131] For example, the oxidizing agent in a polishing slurry can oxidize the polishing surface (e.g., a metal layer such as a tungsten layer) to form a metal oxide (e.g., tungsten oxide) on the polishing surface at a predetermined thickness, and during polishing, branched polymers and / or their micelles can polish the surface by physically and / or chemically removing the metal oxide. In this way, the polishing slurry can effectively remove the polishing surface without inorganic abrasives such as silica, and can effectively prevent defects on the polished surface caused by inorganic abrasives, such as scratches, and damage caused by inorganic abrasive residues.

[0132] Reference Figure 5 A capping layer 50 is formed on the embedded conductive pattern 40a and dielectric layer 20. The capping layer 50 may include, but is not limited to, SiN and / or SiC.

[0133] The planarization used to form the embedded conductive pattern 40a is described below. Planarization can be performed by chemical mechanical polishing (CMP) using a chemical mechanical polishing (CMP) device as described above.

[0134] Figure 6 This is a schematic diagram illustrating a chemical mechanical polishing apparatus according to an embodiment.

[0135] Reference Figure 6 According to the example, the chemical mechanical polishing apparatus 100 may include, for example, a lower base (not shown); a platen 120 rotatably disposed on the upper surface of the lower base; a polishing head 130; a polishing pad 150 on the platen 120; a pad conditioner 160; and at least one polishing slurry supply device 140 disposed adjacent to the polishing pad 150 to supply polishing slurry to the polishing pad 150.

[0136] The platform 120 can be rotatably mounted on the surface of the lower base. For example, the platform 120 can receive rotational power from a motor (not shown) disposed in the lower base, and can therefore be rotated in a certain direction (e.g., clockwise or counterclockwise) via a rotation shaft 120S perpendicular to the surface of the platform 120.

[0137] A polishing head 130 may be disposed on a stage 120 and may hold an object to be polished. The object to be polished may be a semiconductor substrate 10, such as a silicon wafer, and the semiconductor substrate 10 may be covered with a dielectric layer 20 having trenches 20a and a metal layer 40 as described above. The polishing head 130 may include a rotation axis 130S for rotating the object to be polished. When polishing is performed, the rotation direction of the polishing head 130 may be opposite to the rotation direction of the stage 120.

[0138] A polishing pad 150 may be disposed on a stage 120 and supported by the stage 120. The polishing pad 150 may rotate together with the stage 120. The polishing pad 150 may have a rough-formed polishing surface 150S. This polishing surface 150S can mechanically polish the surface of the semiconductor substrate 10 by direct contact with it. The polishing pad 150 may be made of a porous material having a plurality of microspaces, and said plurality of microspaces may contain polishing slurry. The polishing surface 150S of the polishing pad 150 may include a surface that directly contacts the object to be polished and a region at a predetermined depth therefrom, and said predetermined depth may be about 10% to about 100%, about 20% to about 100%, about 30% to about 100%, about 40% to about 100%, or about 50% to about 100% of the thickness of the polishing pad 150. The polishing surface 150S of the polishing pad 150 may be, for example, flat. The polishing surface 150S of the polishing pad 150 may have, for example, protrusions or grooves.

[0139] The pad conditioner 160 can be adjacent to the polishing pad 150 and can maintain the state of the polishing surface 150S, so that the surface of the semiconductor substrate 10 can be effectively polished during the polishing process.

[0140] A polishing slurry supply device 140 may be adjacent to a polishing pad 150 and may supply polishing slurry from a polishing slurry tank 145 to the polishing pad 150. The polishing slurry supply device 140 may include nozzles capable of supplying polishing slurry onto the polishing pad 150 during the polishing process. The polishing slurry supply device 140 may supply polishing slurry.

[0141] Chemical mechanical polishing can be performed, for example, by setting the semiconductor substrate 10 and the polishing pad 150 facing each other, supplying polishing slurry from the polishing slurry supply device 140 between the semiconductor substrate 10 and the polishing pad 150, and polishing by bringing the surface of the semiconductor substrate 10 into contact with the polishing pad 150.

[0142] For example, the polishing slurry can be supplied at a rate of approximately 10 ml / min to approximately 300 ml / min.

[0143] Polishing can be performed by mechanical friction through contacting the surface of the semiconductor substrate 10 with the polishing pad 150 and rotating it. For example, a pressure of about 1 psi to about 5 psi can be applied during polishing.

[0144] Although the method for manufacturing a semiconductor device according to the embodiments has been described above, it is not limited thereto and can be applied to semiconductor devices with various structures.

[0145] The embodiments are described in more detail below with reference to examples. However, these embodiments are exemplary, and the scope of the claims is not limited thereto.

[0146] Synthesis Example: Synthesis of Branched Polymers

[0147] Synthesis Example 1

[0148] [Reaction Scheme 1]

[0149]

[0150] Potassium methoxide (2.185 g, 31.15 mmol) was added to a methanol solution of 1,1,1-tris(hydroxymethyl)propane (4.18 g, 31.15 mmol) and stirred for 2 hours to activate the initiator and prepare an initiator solution. The initiator solution was then heated to 40°C and vacuum distilled. Toluene was injected into the initiator from which methanol had been removed and two azeotropic distillations were performed under reduced pressure. Dry NMP (10 mL, 1 mL per 3 g glycidyl) was added and stirred to prepare a fresh initiator solution. Glycidyl (30 g, 405 mmol) was added dropwise over 24 hours to the fresh initiator solution heated to 80°C, and the mixture was stirred for another 12 hours to proceed with polymerization. The polymer solution was then cooled to room temperature, the reaction was stopped with excess methanol, and precipitation was performed twice in cold diethyl ether. The product collected after precipitation was dissolved in methanol and then treated twice with Amberlite IR-120(H) ion exchange resin. Subsequently, the polymer solution was vacuum distilled to remove methanol, yielding a pale yellow, transparent polymer 1.

[0151] In reaction scheme 1, the structure of polymer 1 should be understood as follows: Each * in the string is connected to a .

[0152] The number-average molecular weight (Mn), weight-average molecular weight (Mw), and polydispersity index (PDI) of polymer 1 are 970, 1320, and 1.38, respectively.

[0153] 1 H NMR (400 MHz, D2O) δ 4.07 - 3.35 (m, 222H), 1.41 - 1.25 (m, 6H), 0.83 (d, J = 7.1 Hz, 9H).

[0154] MALDI-ToF: [M + Na] + 675.5

[0155] Synthesis Example 2

[0156] [Reaction Scheme 2]

[0157]

[0158] Potassium methoxide (2.185 g, 31.15 mmol) was added to a methanol solution of 4-tert-octylphenol (6.428 g, 31.15 mmol) and stirred for 2 hours to activate the initiator and prepare an initiator solution. The initiator solution was then heated to 40°C and vacuum distilled. Toluene was injected into the initiator from which methanol had been removed and two azeotropic distillations were performed under reduced pressure. Dry NMP (10 mL, 1 mL per 3 g glycidyl) was added and stirred to prepare a fresh initiator solution. Glycidyl (30 g, 405 mmol) was added dropwise over 24 hours to the fresh initiator solution heated to 80°C, and the mixture was stirred for another 12 hours to proceed with polymerization. The polymer solution was then cooled to room temperature, the reaction was stopped with excess methanol, and precipitation was performed twice in cold diethyl ether. The product collected after precipitation was dissolved in methanol and then treated twice with Amberlite IR-120(H) ion exchange resin. The polymer solution was then vacuum distilled to remove methanol, yielding a pale yellow, transparent polymer 2.

[0159] The number-average molecular weight (Mn), weight-average molecular weight (Mw), and polydispersity index (PDI) of polymer 2 are 760, 1040, and 1.37, respectively.

[0160] 1 H NMR (300 MHz, D2O) δ 7.45 (d, J = 8.7 Hz, 2H), 6.98 (d, 8.1 Hz,2H), 4.34 - 3.42 (m, 97H), 1.75 (s, 2H), 1.31 (s, 6H) 0.71 (s, 9H).

[0161] MALDI-ToF: [M + Na] + 673.5

[0162] Synthesis Example 3

[0163] [Reaction Scheme 3]

[0164]

[0165] Potassium methoxide (2.185 g, 31.15 mmol) was added to a methanol solution of benzyl alcohol (3.37 g, 31.15 mmol) and stirred for 2 hours to activate the initiator and prepare an initiator solution. The initiator solution was then heated to 40°C and vacuum distilled. Toluene was injected into the initiator from which methanol had been removed and two azeotropic distillations were performed under reduced pressure. Dry NMP (10 mL, 1 mL per 3 g glycidyl) was added and stirred to prepare a fresh initiator solution. Glycidyl (30 g, 405 mmol) was added dropwise over 24 hours to the fresh initiator solution heated to 80°C, and the mixture was stirred for another 12 hours to proceed with polymerization. The polymer solution was then cooled to room temperature, and the reaction was stopped with excess methanol. Two precipitations were performed in cold diethyl ether. The product collected after precipitation was dissolved in methanol and then treated twice with Amberlite IR-120(H) ion exchange resin. Subsequently, the polymer solution was vacuum distilled to remove methanol, yielding a pale yellow, transparent polymer 3.

[0166] The number-average molecular weight (Mn), weight-average molecular weight (Mw), and polydispersity index (PDI) of polymer 3 are 520, 720, and 1.38, respectively.

[0167] 1 H NMR (400 MHz, D2O) δ 7.35 (q, J = 5.9, 5.0 Hz, 5H), 4.52 (s, 2H), 4.07 - 3.32 (m, 167H).

[0168] MALDI-ToF: [M + Na] + 649.4

[0169] Synthesis Example 4

[0170] [Reaction Scheme 4]

[0171]

[0172] 17.6 g (197.7 mmol of OH groups) of polymer 1 obtained in Synthetic Example 1 was dissolved in 176 mL of DMF, and 47.2 g (296.7 mmol) of SO3 / pyridine complex was added while stirring at 60°C. The mixture was then stirred for 24 hours to obtain polymer 4-I. Next, 50 mL of distilled water was added, followed by the addition of 1 M NaOH solution until the pH reached 9 to prepare a polymer solution. The polymer solution was then purified by dialyzing with saturated NaCl solution for 2 days and then with distilled water for 2 days. Finally, the purified polymer solution was concentrated under reduced pressure and freeze-dried to obtain polymer 4 as a pale yellow solid. In reaction scheme 4, the structures of polymer 4-I and polymer 4 should be understood in a similar manner to those of polymer 1 in reaction scheme 1.

[0173] The number-average molecular weight of polymer 4 is 2,570.

[0174] 1 H NMR (400 MHz, D2O) δ 4.45 - 3.35 (m, 196H), 1.47 (dt, J = 15.3, 8.0Hz, 6H), 0.93 (s, 9H).

[0175] Synthesis Example 5

[0176] [Reaction Scheme 5]

[0177]

[0178] 17.0 g (159.3 mmol of OH groups) of polymer 2 obtained in Synthetic Example 2 was dissolved in 170 mL of DMF, and 38 g (239 mmol) of SO3 / pyridine complex was added while stirring at 60°C. The mixture was then stirred for 24 hours to obtain polymer 5-I. Next, 50 mL of distilled water was added to polymer 5-I, followed by the addition of 1 M NaOH solution until the pH reached 9 to prepare a polymer solution. The polymer solution was then purified by dialyzing with saturated NaCl solution for 2 days and then with distilled water for 2 days. Finally, the purified polymer solution was concentrated under reduced pressure and freeze-dried to obtain polymer 5 as a pale yellow solid.

[0179] The number-average molecular weight of polymer 5 is 3,100.

[0180] 1H NMR (400 MHz, D2O) δ 7.50 (d, J = 8.2 Hz, 2H), 7.04 (d, J = 8.2 Hz, 2H), 4.43 - 3.36 (m, 128H), 1.78 (s, 2H), 1.38 (s, 6H), 0.73 (d, J = 5.5 Hz, 9H).

[0181] Synthesis Example 6

[0182] [Reaction Scheme 6]

[0183]

[0184] 13.0 g (145 mmol of OH groups) of polymer 3 obtained in Synthetic Example 3 was dissolved in 130 mL of DMF, and 34.6 g (218 mmol) of SO3 / pyridine complex was added while stirring at 60°C. The mixture was then stirred for 24 hours to obtain polymer 6-I. Next, 50 mL of distilled water was added to polymer 6-I, followed by the addition of 1 M NaOH solution until the pH reached 9 to prepare a polymer solution. The polymer solution was then purified by dialyzing with saturated NaCl solution for 2 days and then with distilled water for 2 days. Finally, the purified polymer solution was concentrated under reduced pressure and freeze-dried to obtain polymer 6 as a pale yellow solid.

[0185] The number-average molecular weight of polymer 6 is 5,820.

[0186] 1 H NMR (400 MHz, DO) δ 7.41 (s, 5H), 4.67 - 3.44 (m, 274H).

[0187] Synthesis Example 7

[0188] [Reaction Scheme 7]

[0189]

[0190] A solution of 108.5 g (931.5 mmol) sodium chloroacetate dissolved in 130 mL of distilled water was slowly added over 30 minutes to a mixture of 27.6 g (310.5 mmol of OH groups) of polymer 1 obtained in Synthetic Example 1 and 124.2 g (931.5 mmol of NaOH) of 30% NaOH. The reaction mixture was then heated to 80°C and reacted for 16 hours, cooled to room temperature, neutralized with 2N hydrochloric acid, and concentrated under reduced pressure. The reaction product was then purified by dialyzing with distilled water. Finally, the purified solution was concentrated under reduced pressure and freeze-dried to obtain polymer 7 as a colorless solid.

[0191] The number-average molecular weight of polymer 7 is 2,110.

[0192] 1 H NMR (400 MHz, D2O) δ 4.24 - 3.32 (m, 132H), 1.35 (s, 2H), 0.85 (s,3H).

[0193] Synthesis Example 8

[0194] [Reaction Scheme 8]

[0195]

[0196] A solution of 108.5 g (931.5 mmol) sodium chloroacetate dissolved in 130 mL of distilled water was slowly added over 30 minutes to a mixture of 23.0 g (310.5 mmol of OH groups) of polymer 2 obtained in Synthetic Example 2 and 124.2 g (931.5 mmol of NaOH) of 30% NaOH. The reaction mixture was then heated to 80°C and reacted for 16 hours, cooled to room temperature, neutralized with 2N hydrochloric acid, and concentrated under reduced pressure. The reaction product was then purified by dialyzing with distilled water. Finally, the purified solution was concentrated under reduced pressure and freeze-dried to obtain polymer 8 as a colorless solid.

[0197] The number-average molecular weight of polymer 8 is 2,580.

[0198] 1 H NMR (400 MHz, D2O) δ 7.44 (d, J = 8.4 Hz, 2H), 6.97 (d, J = 7.9 Hz, 2H), 4.21 - 3.41 (m, 128H), 1.73 (s, 2H), 1.33 (s, 6H), 0.75 - 0.61 (m, 9H).

[0199] Synthesis Example 9

[0200] [Reaction Scheme 9]

[0201]

[0202] A solution of 108.5 g (931.5 mmol) sodium chloroacetate dissolved in 130 mL of distilled water was slowly added over 30 minutes to a mixture of 27.8 g (310.5 mmol of OH groups) of polymer 3 obtained in Synthetic Example 3 and 124.2 g (931.5 mmol of NaOH) of 30% NaOH. The reaction mixture was then heated to 80°C and reacted for 16 hours, cooled to room temperature, neutralized with 2N hydrochloric acid, and concentrated under reduced pressure. The reaction product was then purified by dialyzing with distilled water. Finally, the purified solution was concentrated under reduced pressure and freeze-dried to obtain polymer 9 as a colorless solid.

[0203] The number-average molecular weight of polymer 9 is 4,410.

[0204] 1 H NMR (400 MHz, DO) δ 7.46 (s, 5H), 4.63 (s, 2H), 4.12 - 3.48 (m, 260H).

[0205] Evaluation I: Evaluation of micelle formation

[0206] A slurry comprising the polymer according to the synthesis examples was prepared, and the formation of micelles was evaluated.

[0207] The polymer according to Synthesis Example 2 was stirred at 70°C for 4 hours, and then stirred at room temperature for more than 24 hours. The result was then diluted with deionized water to concentrations of 1 wt%, 2.5 wt%, 5 wt%, and 25 wt%, stirred for 30 minutes, and filtered to prepare slurries. The pH of each slurry was 3.

[0208] The particle size and distribution of micelles measured by dynamic light scattering (DLS) are shown in Table 1.

[0209] Table 1

[0210]

[0211] *ID: Intensity Distribution

[0212] *ND: Quantity Distribution

[0213] *VD: Volume distribution

[0214] *Z-mean: Z-mean size

[0215] *PDI: Multidispersion Index

[0216] Intensity distribution (ID) is a particle size distribution weighted by the scattering intensity of each particle, and the corresponding average particle size is the intensity-average size.

[0217] Number distribution (ND) is a particle size distribution weighted by the number of each particle, and the average particle size calculated accordingly is the number-average size.

[0218] Volume distribution (VD) is a particle size distribution that is calculated based on the intensity distribution according to Mie theory, the particle volume is weighted accordingly, and the average particle size is calculated as the volume average size.

[0219] Z-mean size (Z-average) is the average particle size obtained through cumulative analysis of intensity distribution and can be defined according to the ISO 22412 method. Z-mean size can also be the particle size obtained according to the dynamic light scattering (DLS) method.

[0220] The polydispersity index (PDI) is an index that indicates the uniformity of particle distribution. Generally, the closer it is to 0, the more uniform the particle distribution.

[0221] Referring to Table 1, it can be confirmed that the slurry comprises micelles in the form of particles with a size of several nanometers formed from the polymer according to the synthesis examples, and that the particle size distribution of the micelles in the slurry is relatively uniform. It can also be confirmed that the micelle size can be controlled depending on the polymer concentration.

[0222] Preparation Example: Preparation of Polishing Slurry

[0223] Preparation Example 1

[0224] A polishing slurry with a pH of 3 was prepared by mixing 1.5 wt% of polymer 7 obtained in synthesis example 7, 2.4 wt% of hydrogen peroxide (oxidant 1), 0.0104 wt% of Fe(NO3)3·9H2O (oxidant 2), 0.08 wt% of malonic acid (oxidant), nitric acid (pH adjuster), and the balance of deionized water.

[0225] Preparation Example 2

[0226] The polishing slurry was prepared in the same manner as in Preparation Example 1, except that polymer 8 obtained in Synthesis Example 8 was used instead of polymer 7 obtained in Synthesis Example 7.

[0227] Preparation Example 3

[0228] The polishing slurry was prepared in the same manner as in Preparation Example 1, except that polymer 5 obtained in Synthesis Example 5 was used instead of polymer 7 obtained in Synthesis Example 7.

[0229] Example

[0230] Example 1

[0231] Chemical mechanical polishing (CMP) is performed under the following conditions.

[0232] (1) CMP equipment: GnP tech POLY762 (G&P Technology, Inc.)

[0233] (2) Object to be polished: Tungsten layer (a 3,000 Å thick tungsten layer on a 12-inch silicon wafer covered with multiple trenches of silicon oxide (dielectric) with a width of 200 nm; the arrangement of the tungsten layer and silicon oxide can be found in [reference]). Figure 3 )

[0234] (3) Polishing head rotation speed: 121 rpm

[0235] (4) Polishing pad rotation speed: 119 rpm

[0236] (5) Applied pressure: 3.0 psi

[0237] (6) Initial temperature: 24°C

[0238] (7) Polishing slurry: The polishing slurry prepared according to Example 1.

[0239] (8) Polishing slurry supply flow rate: 180 sccm

[0240] (9) Polishing time: 60 seconds

[0241] Example 2

[0242] Chemical mechanical polishing was performed in the same manner as in Example 1, except that the polishing slurry prepared according to Preparation Example 2 was used instead of the polishing slurry prepared according to Preparation Example 1.

[0243] Example 3

[0244] Chemical mechanical polishing was performed in the same manner as in Example 1, except that the polishing slurry prepared according to Preparation Example 3 was used instead of the polishing slurry prepared according to Preparation Example 1.

[0245] Example 4

[0246] Chemical mechanical polishing was performed in the same manner as in Example 1, except that the polishing time was increased to more than 60 seconds until the patterned portion (silicon oxide) was exposed.

[0247] Reference Example 1

[0248] Chemical mechanical polishing was performed in the same manner as in Example 1, except that a polishing slurry containing silica (Samsung SDI) was used instead of the polishing slurry prepared according to Example 1.

[0249] Evaluation II

[0250] The polishing performance of chemical mechanical polishing according to the examples and reference examples was evaluated.

[0251] Polishing performance is evaluated using polishing rate (RR) and polishing selectivity.

[0252] The polishing rate (RR) is calculated using Equation 2.

[0253] [Equation 2]

[0254] Polishing rate (RR, Å / min) = (Initial film thickness (Å) - Film thickness after polishing (Å)) / Polishing time (min)

[0255] In Equation 2, the thickness of the tungsten layer (initial film thickness and film thickness after polishing) can be calculated according to Equation 3, and the volume resistivity and surface resistivity in Equation 3 can be measured using a DC 4 probe method with a ohmmeter (KLA Tencor, model RS-100).

[0256] [Equation 3]

[0257] Film thickness (Å) = [Volume resistivity (Ωm) ÷ Thin film resistance (Ω)] x 10 10

[0258] In Equation 2, the film thickness of the oxide layer (initial film thickness and film thickness after polishing) can be measured using reflectometry and can be measured using a film thickness measuring device (Filmetrics, model F20).

[0259] Polishing selectivity is the ratio of the polishing rate of the tungsten layer to the polishing rate of the oxide (silicon oxide) layer.

[0260] The results are shown in Table 2.

[0261] Table 2

[0262]

[0263] *RR1: Polishing rate of tungsten layer

[0264] *RR2: Polishing rate of oxide layer

[0265] *RR1 / RR2: Polishing selectivity

[0266] Referring to Table 2, it can be confirmed that the polishing slurry used in the examples exhibits a good polishing rate and high tungsten / oxide polishing selectivity compared to the polishing slurry used in the reference examples. Thus, it can be confirmed that, compared to polishing slurries containing inorganic abrasives, the polishing slurry used in the examples demonstrates a good level of polishing rate through polymers and / or micelles without inorganic abrasives, while significantly improving polishing selectivity.

[0267] Evaluation III

[0268] The polishing products of chemical mechanical polishing (CMP) according to the examples and reference examples were evaluated.

[0269] The polishing rate distribution is calculated as follows: a diameter (line) is drawn laterally from the center of the 12-inch wafer, and the standard deviation of the polishing rate measured at 10-millimeter intervals along this diameter (line) is divided by the average polishing rate. This numerically reveals the uniformity of the overall polishing of the finished product.

[0270] The results are shown in Figures 7A to 8B And in Table 3.

[0271] Figure 7A The image shows a SEM image of the surface of the polished product obtained by chemical mechanical polishing according to Example 4. Figure 7B This is a SEM image of the cross-section of the polished product obtained by chemical mechanical polishing according to Example 4. Figure 7C The image shows a SEM image of the surface of the polished product obtained by chemical mechanical polishing according to Example 1. Figure 8A The image shows a SEM image of the surface of the polished product obtained by chemical mechanical polishing according to Reference Example 1. Figure 8B The image shows a cross-sectional SEM image of the polished product obtained by chemical mechanical polishing according to Reference Example 1.

[0272] Table 3

[0273]

[0274] Reference Figures 7A to 7C As can be seen from Table 3, the polishing product of the chemical mechanical polishing according to the embodiments forms a conductive pattern (metal) with high surface flatness (low surface roughness), without any residue of inorganic abrasives or polymer micelles, with almost no scratches or other defects, and without significant etching or erosion of adjacent oxide films. Conversely, referring to... Figure 8A and 8BAs can be seen, the polishing product of chemical mechanical polishing according to the reference example has a large amount of residual inorganic abrasive residue, many defects such as scratches, and a significant amount of etching or erosion of the adjacent oxide film.

[0275] Thus, it can be confirmed that the chemical mechanical polishing according to the embodiments can prevent defects such as scratches caused by inorganic abrasives and damage caused by inorganic abrasive residues, while exhibiting good physical polishing effect and minimal chemical etching caused by polymers and / or micelles, thereby exhibiting improved polishing performance.

[0276] While this disclosure has been described with respect to exemplary embodiments which are now considered practical, it will be understood that the invention is not limited to the disclosed embodiments. Rather, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. Polishing slurry, including: Branched polymers comprising hydrophobic units, micelles of said branched polymers, or combinations thereof, and Dispersion medium.

2. The polishing slurry according to claim 1, wherein the hydrophobic unit comprises substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C3-C30 cycloalkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C6-C30 aromatic group, substituted or unsubstituted siloxane group, or combinations thereof.

3. The polishing slurry according to claim 1, wherein... The branched polymer further includes hydrophilic functional groups located at the ends of the branched polymer, and The hydrophilic functional groups include hydroxyl groups, sulfonate groups, carboxylate groups, phosphonate groups, ammonium groups, and pyrrolidine groups. group, imidazole Groups, amino groups, amide groups, aldehyde groups, ketone groups, epoxy groups, or combinations thereof.

4. The polishing slurry according to claim 1, wherein the branched polymer comprises structural units derived from glycerol, ethylene glycol, propylene glycol, ethyleneimine, piperazine, trimethylolpropane, sorbitol, acrylic acid, methacrylic acid, their derivatives, or combinations thereof.

5. The polishing slurry according to claim 4, wherein the branched polymer comprises 2 to 100 structural units.

6. The polishing slurry according to claim 1, wherein the branched polymer comprises a structural unit represented by chemical formula A and a terminal portion represented by chemical formula B: [Chemical Formula A] [Chemical Formula B] in, In chemical formulas A and B, X 1 and X 2 Each is independently a hydrogen or hydrophilic functional group, and * indicates a connection point with an adjacent structural unit.

7. The polishing slurry according to claim 6, wherein X 1 and X 2 Each of the following groups is independently composed of hydrogen, sulfonate, carboxylate, phosphonate, ammonium, or pyrrolidine. group, imidazole Groups, amino groups, amide groups, aldehyde groups, ketone groups, epoxy groups, or combinations thereof.

8. The polishing slurry according to claim 1, wherein the branched polymer has a weight-average molecular weight of 300 to 10,000.

9. The polishing slurry of claim 1, wherein the micelles are in the form of an assembly of a plurality of the branched polymers, and The micelles include The core in which the hydrophobic unit is assembled, and The shell includes polymer segments comprising hydrophilic functional groups and structural units derived from glycerol, ethylene glycol, propylene glycol, ethyleneimine, piperazine, trimethylolpropane, sorbitol, acrylic acid, methacrylic acid, their derivatives, or combinations thereof.

10. The polishing slurry according to claim 1, wherein the particle size of the micelles, measured by dynamic light scattering in an aqueous medium, is from 1 nm to 50 nm.

11. The polishing slurry of claim 1, wherein the branched polymer, the micelles, or a combination thereof are included in an amount from 0.1% to 30% by weight, based on the total amount of the polishing slurry.

12. The polishing slurry according to claim 1, further comprising an oxidizing agent. The polishing slurry mentioned herein does not include inorganic abrasives.

13. A method for manufacturing a semiconductor device, the method comprising: A conductive layer is formed on a trenched dielectric layer. The polishing slurry according to any one of claims 1 to 12 is supplied to the conductive layer, and The conductive layer is chemically and mechanically polished to form a conductive pattern embedded in the trench.

14. The method of claim 13, wherein The temperature of the polishing slurry used in the chemical mechanical polishing process is between room temperature and 70°C.

15. Micelles of a branched polymer, said micelles comprising: The core in which hydrophobic units are assembled, and The shell comprises polymer segments including hydrophilic functional groups and structural units derived from glycerol, ethylene glycol, propylene glycol, ethyleneimine, piperazine, trimethylolpropane, sorbitol, acrylic acid, methacrylic acid, their derivatives, or combinations thereof. The particle size of the micelles, measured by dynamic light scattering in an aqueous medium, ranges from 1 nm to 50 nm.

16. The micelles according to claim 15, wherein The hydrophobic unit includes substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C3-C30 cycloalkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C6-C30 aromatic group, substituted or unsubstituted siloxane group, or combinations thereof, and The hydrophilic functional groups include hydroxyl groups, sulfonate groups, carboxylate groups, phosphonate groups, ammonium groups, and pyrrolidine groups. group, imidazole Groups, amino groups, amide groups, aldehyde groups, ketone groups, epoxy groups, or combinations thereof.

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