Silica NANO particle having core-shell structure, chemical mechanical polishing composition comprising same and method for manufacturing semiconductor device using same

Abstract

One embodiment of the present invention provides silica nanoparticles having a core-shell structure. The particles may be formed by controlling the condensation reaction conditions of a silicon precursor in stages to form a core region having a first bonding structure and reinforce it, and then modifying the reaction environment to form a shell region having a second bonding structure on the core surface. Through this, a core with excellent mechanical strength and a shell with high chemical reactivity are simultaneously realized within a single particle, thereby providing high-purity silica nanoparticles capable of achieving a high polishing rate and low surface defects in a chemical mechanical polishing process.

Description

Technology Field

[0001] The present invention relates to silica nanoparticles having a core-shell structure, a chemical mechanical polishing composition containing the same, and a method for manufacturing a semiconductor device using the same. More specifically, the invention relates to a method for manufacturing silica nanoparticles that improve polishing efficiency by forming a dual structure of a core and a shell having different physical properties, a method for manufacturing a chemical mechanical polishing slurry composition containing the same as polishing particles, and a method for manufacturing a semiconductor device that polishes a semiconductor substrate using the slurry. Background Technology

[0003] With the trend toward high integration and miniaturization of semiconductor devices, the importance of local or global planarization technology for wafer surfaces during the manufacturing process is gradually increasing. Chemical Mechanical Polishing (CMP) is one of the core technologies for removing step heights in thin films formed on semiconductor wafers and planarizing the surface; it performs polishing by simultaneously utilizing chemical reactions and mechanical friction. The performance of the CMP process, such as the removal rate (RR), planarization efficiency, and surface defects after polishing, depends significantly on the characteristics of the slurry used as well as process variables.

[0004] CMP slurry is generally a liquid dispersion containing various chemical additives such as abrasive particles, dispersants, pH adjusters, oxidizers, and corrosion inhibitors. Among these, abrasive particles play a primary role in mechanically removing the film to be polished, and the type, size, shape, hardness, concentration, and dispersion stability of the particles directly affect the results of the CMP process. Among the various types of abrasive particles, silica (SiO2) nanoparticles have been widely used as abrasive particles for CMP slurry because they are relatively inexpensive, easy to control in terms of particle size and shape, chemically stable, and allow for the control of reactivity with the film to be polished.

[0005] Conventional silica nanoparticles are primarily manufactured through sol-gel processes, with the Stober method being a representative example, in which silicon precursors such as alkoxysilanes are hydrolyzed and condensed under a basic catalyst (e.g., ammonia) in an alcohol solvent. However, while this Stober method-based process can produce high-purity silica particles, there were economic limitations to mass production due to the high cost of the alkoxysilane precursors and the slow reaction rate.

[0006] To address these issues and reduce production costs, the use of inexpensive sodium silicate, specifically water glass (Na2SiO3), as a silicon precursor has been widely adopted. While using water glass offers the advantage of producing large quantities of silica particles at a low cost, it causes serious problems due to the high concentration of alkali metal ion impurities, such as sodium (Na), remaining in the final silica particles. In semiconductor device manufacturing processes, metal impurities, particularly highly mobile alkali metal ions, penetrate into insulating films such as gate oxides. This leads to degradation of the device's electrical characteristics—such as lowering dielectric breakdown voltage and increasing leakage current—and severely impairs long-term reliability. Consequently, the use of water glass-based silica particles is inevitably limited in semiconductor CMP processes that require a high degree of cleanliness.

[0007] Meanwhile, various studies have been conducted to control the shape of silica particles as part of efforts to improve the polishing rate of the CMP process. For example, it has been reported that cocoon-shaped or doublet particles, formed by connecting two or more spherical silica particles to resemble a snowman or peanut, can exhibit higher polishing rates compared to ordinary spherical particles due to differences in contact area with the target surface or stress concentration effects. However, the process of manufacturing particles with these special shapes has the disadvantage of being very complex and difficult to control. Generally, non-spherical particles are formed by first synthesizing spherical silica particles (seed particles) and then rapidly changing the pH of the reaction solution to specific conditions, such as near the isoelectric point, to neutralize the particle surface charge and induce aggregation between particles via van der Waals forces. However, silica nanoparticles are highly sensitive to pH changes, making it prone to unintended gelation or random aggregation during the pH adjustment process. As a result, problems have been continuously raised regarding the difficulty of selectively obtaining only the desired cocoon-shaped particles in high yield, the non-uniformity of the shape and size of the manufactured particles, and the difficulty in ensuring process reproducibility.

[0008] Furthermore, the size uniformity and distribution control of the silica particles themselves are also critical factors for CMP performance. Conventional batch or one-pot synthesis methods, which involve adding the entire reactant mixture at once, tend to result in irregular, simultaneous nucleation and subsequent particle growth during the initial reaction. Consequently, the final particles tend to have a wide size distribution and poor uniformity. If particle sizes are non-uniform, and even a small amount of particles significantly larger than the average size are present, these large particles become a major cause of surface defects—such as severe scratches or micro-scratches—on the wafer surface during the CMP process. Such defects can lead to pattern formation errors or device performance degradation in subsequent processes. To control particle size more precisely, semi-batch or continuous injection methods have been proposed, in which silicon precursors are slowly added to the reaction solution at a constant rate. This method can improve particle size distribution compared to the batch method by controlling the nucleation stage and growth rate, but there were still limitations in actively controlling the internal structure or surface characteristics of the particles.

[0009] Recently, some research has been conducted on abrasive particles with a core-shell structure to improve CMP performance. For instance, there are attempts to simultaneously optimize mechanical and chemical properties by combining cores and shells with different materials or characteristics. However, existing research on core-shell silica particles has primarily focused on introducing organic shells or coating with heterogeneous inorganic shells; consequently, approaches aimed at improving performance by controlling the structural properties of the silica itself (e.g., density, porosity, bonding structure) differently between the core and shell have been insufficient. In particular, there is a need for the development of technology to maximize CMP performance by manufacturing particles composed solely of pure silica that possess distinct physical properties for the core and shell, such as density or the regularity of the Si-O-Si bonding structure.

[0010] In summary, conventional silica nanoparticle manufacturing technologies for CMP have faced problems such as (1) metal impurity contamination issues arising from the use of water glass for low-cost production, (2) complexity, low yield, and reproducibility issues in manufacturing cocoon-shaped particles to improve polishing rates, (3) difficulty in controlling particle size and structural uniformity in batch or simple semi-batch processes, and (4) the absence of performance optimization strategies through pure silica-based core-shell structures. Therefore, to satisfy the high-purity, high-performance, and high-reliability CMP processes required by the semiconductor industry, there is an urgent need to develop silica nanoparticles with a new structure that can maximize polishing performance without complex shape control while having a uniform size without metal impurities, as well as innovative manufacturing methods capable of stably mass-producing such nanoparticles. The problem to be solved

[0012] The present invention has been devised to solve the aforementioned problems, and one embodiment of the present invention provides a method for manufacturing silica nanoparticles having a core-shell structure.

[0013] In addition, another embodiment of the present invention provides core-shell silica nanoparticles prepared by the above method.

[0014] In addition, another embodiment of the present invention provides a method for manufacturing a chemical mechanical polishing composition.

[0015] In addition, another embodiment of the present invention provides a chemical mechanical polishing composition.

[0016] In addition, another embodiment of the present invention provides a method for manufacturing a semiconductor device.

[0017] However, the technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0019] As a technical means for achieving the aforementioned technical problem, one aspect of the present invention is,

[0020] A method for manufacturing silica nanoparticles comprises: (a) forming a first region having a first Si-O-Si bond structure through a condensation reaction of a silicon precursor under a first pH condition; (b) raising the temperature of the reaction solution in which the first region is formed to a second temperature condition higher than the first temperature condition to strengthen the Si-O-Si bond structure of the first region; and (c) adding an alcohol to the reaction solution containing the strengthened first region and further proceeding with the condensation reaction of the silicon precursor to form a second region having a second Si-O-Si bond structure on the surface of the first region.

[0021] The above silicon precursor may be any one selected from the group consisting of tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), tetrapropoxysilane, tetrabutoxysilane, methyltriethoxysilane (MTES), methyltrimethoxysilane (MTMS), vinyltriethoxysilane, and phenyltriethoxysilane.

[0022] The above alcohol may be any one selected from the group consisting of methanol, ethanol, propanol, isopropanol, and butanol.

[0023] The first pH condition of step (a) above may be 7.5 to 10.0.

[0024] The above step (a) may be performed under a first temperature condition of 80°C to 90°C.

[0025] Step (a) above may involve introducing the hydrolysis solution containing the silicon precursor using a metering pump, while increasing the introduction rate over time.

[0026] The second temperature condition of step (b) above may be 90°C to 105°C.

[0027] The above step (b) may be performed for 2 to 6 hours.

[0028] The above step (b) may be performed while maintaining the solid content concentration of the reaction solution containing the first region at 20% or less.

[0029] Through the above step (b), the polydispersity index (PDI) of the particle in which the first region is formed may be reduced.

[0030] The alcohol in step (c) above may be added in an amount corresponding to 1 / 5 to 1 / 3 of the total volume of the reaction solution.

[0031] After adding the alcohol in step (c) above, a stabilization step of at least 30 minutes may be additionally included.

[0032] The condensation reaction of step (c) above may be carried out under pH conditions of 8.0 to 9.0.

[0033] In step (c) above, the input rate of the silicon precursor may be faster than the final input rate of step (a).

[0034] Prior to step (a) above, the method may further include a step of preparing a hydrolysis solution by mixing water, an acid catalyst, and the silicon precursor.

[0035] The concentration of the silicon precursor in the above hydrolysis solution may be 25% to 45%.

[0036] Prior to step (a) above, the method may additionally include a step of preparing a reaction mother liquor by adding a basic catalyst to water.

[0037] The above basic catalyst may be any one selected from the group consisting of ammonia water, sodium hydroxide, potassium hydroxide, triethylamine, and ethylenediamine.

[0039] Another aspect of the present invention is,

[0040] The present invention provides a core-shell silica nanoparticle comprising: a core having a first Si-O-Si bonding structure; and a shell formed on the surface of the core and having a second Si-O-Si bonding structure, wherein the full width at half maximum (FWHM) of the peak exhibiting maximum intensity at 20° to 30° (2θ) during X-ray diffraction (XRD) analysis is 6.6° or less.

[0041] The above core may be obtained by reinforcing wet-grown growth particles.

[0042] When analyzing the above X-ray diffraction (XRD), an amorphous peak may be observed in the range of 20° to 23° (2θ), and a crystalline peak may be observed in the range of 26° to 28° (2θ).

[0043] The above-mentioned growth particles may have a d-spacing value of 3.90 Å or more and 4.05 Å or less according to Bragg's law.

[0044] The above core may have a d-spacing value according to Bragg's law of 3.95 Å or more and 4.05 Å or less.

[0045] The above core-shell silica nanoparticles may have a d-spacing value of 3.95 Å or more and 4.05 Å or less according to Bragg's law.

[0046] The above-mentioned growth particles may have a ratio of the maximum intensity of the crystalline peak to the maximum intensity of the amorphous peak of 0.07 to 0.12.

[0047] The above core may have a ratio of the maximum intensity of the crystalline peak to the maximum intensity of the amorphous peak to 0.11 to 0.13.

[0048] The core-shell silica nanoparticles may have a ratio of the maximum intensity of the crystalline peak to the maximum intensity of the amorphous peak that is greater than 0.13 and less than or equal to 0.16.

[0049] The above-mentioned growth particles may have a crosslinking rate defined as (area of ​​crystalline peak) / (area of ​​amorphous peak + area of ​​crystalline peak) of 4.0% or more and less than 8.0%.

[0050] The above core may have a crosslinking rate defined as (area of ​​crystalline peak) / (area of ​​amorphous peak + area of ​​crystalline peak) of 7.0% or more and less than 9.0%.

[0051] The above core-shell silica nanoparticles may have a crosslinking rate defined as (area of ​​crystalline peak) / (area of ​​amorphous peak + area of ​​crystalline peak) of 12.5% ​​or more and 16.0% or less.

[0052] The above-mentioned growth particles may have a full width at half maximum (FWHM) of the amorphous peak of 6.5° or less.

[0053] The above core may have a full width at half maximum (FWHM) of the amorphous peak of less than 6.1°.

[0054] The core-shell silica nanoparticles may have a full width at half maximum (FWHM) of the amorphous peak of less than 6.6°.

[0055] 1 When analyzing H-NMR, peaks attributable to silanol (Si-OH) groups on the silica surface may be observed in the ranges of 1.0 ppm to 1.2 ppm, 1.7 ppm to 1.9 ppm, and 3.4 ppm to 3.6 ppm, respectively.

[0056] The above core is, 29 The amount of Si-O-Si bonds per unit volume in Si-NMR analysis is nm 3 6.0 x 10 per 4 Up to 7.0 x 10 4 It could be.

[0057] The above-mentioned core-shell silica nanoparticles are, 29 The amount of Si-O-Si bonds per unit volume in Si-NMR analysis is nm 3 3.0 x 10 per 4 Up to 4.0 x 10 4 It could be.

[0058] The amount of Si-O-Si bonds per unit volume of the core may be 1.2 to 3.0 times the amount of Si-O-Si bonds per unit volume of the core-shell silica nanoparticles.

[0059] The above-mentioned growth particles are, 1When analyzed by H-NMR, the amount of effective hydroxyl groups (effective OH) on the particle surface is 5.5 x 10⁶ per gram. 6 Up to 8.0 x 10 6 It could be.

[0060] The above core is, 1 When analyzed by H-NMR, the amount of effective hydroxyl groups (effective OH) on the particle surface is 8.5 x 10⁶ per gram. 5 Up to 1.0 x 10 6 It could be.

[0061] The above-mentioned core-shell silica nanoparticles are, 1 When analyzed by H-NMR, the amount of effective hydroxyl groups (effective OH) on the particle surface is 1.05 x 10⁶ per gram. 6 Up to 1.2 x 10 6 It could be.

[0062] The amount of effective hydroxyl groups on the particle surface of the core-shell silica nanoparticles may be 1.05 to 1.5 times the amount of effective hydroxyl groups on the particle surface of the core.

[0063] The above core may have an average diameter of 50 nm to 60 nm as measured by small-angle X-ray scattering (SAXS) analysis.

[0064] The above shell may have an average thickness of 12 nm to 18 nm as measured by small-angle X-ray scattering (SAXS) analysis.

[0065] The core-shell silica nanoparticles may have an average diameter of 65 nm to 75 nm as measured by small-angle X-ray scattering (SAXS) analysis.

[0066] In small-angle X-ray scattering (SAXS) analysis, the scattering vector (q) is 2.5 nm -1 to 9.0 nm -1 The scattering intensity (Absolute Intensity) may decrease within the range.

[0067] In small-angle X-ray scattering (SAXS) analysis, the scattering vector (q) is 12 nm -1 to 17 nm -1 A peak exhibiting maximum intensity within the range may be observed.

[0068] The above-mentioned growth particles may have an average diameter of 55 nm to 68 nm as measured by dynamic light scattering (DLS).

[0069] The above core may have an average diameter of 50 nm to 62 nm as measured by dynamic light scattering (DLS).

[0070] The above core-shell silica nanoparticles may have an average diameter of 60 nm to 75 nm as measured by dynamic light scattering (DLS).

[0071] The above core may have a polydispersity index (PDI) of 0.08 or less, measured by dynamic light scattering (DLS) targeting only the core particles.

[0072] The above core-shell silica nanoparticles may have a polydispersity index (PDI) of 0.08 or higher and 0.15 or lower as measured by dynamic light scattering (DLS).

[0073] The average diameter measured by scanning electron microscope (SEM) may be 45 nm to 70 nm.

[0074] The average diameter measured by scanning electron microscopy (SEM) may be 5 nm to 20 nm smaller than the average diameter measured by dynamic light scattering (DLS).

[0075] The above core-shell silica nanoparticles may have a shell / core thickness ratio of 0.15 or more and 0.5 or less.

[0077] Another aspect of the present invention is,

[0078] A method for preparing a chemical mechanical polishing composition is provided, comprising the steps of: preparing core-shell silica nanoparticles according to the above method; and dispersing the core-shell silica nanoparticles in a solvent.

[0080] Another aspect of the present invention is,

[0081] A chemical mechanical polishing composition comprising the above particles; and a solvent is provided.

[0083] Another aspect of the present invention is,

[0084] A method for manufacturing a semiconductor device is provided, comprising the step of polishing a metal or semiconductor film using the above chemical mechanical polishing composition. Effects of the invention

[0086] According to one embodiment of the present invention, by simultaneously realizing a core region with excellent mechanical strength having a first Si-O-Si bond structure and a shell region with high chemical reactivity having an irregular Si-O-Si bond structure within a single silica nanoparticle, a high polishing rate and low surface defects can be achieved simultaneously during the CMP process.

[0087] In addition, according to one embodiment of the present invention, high-purity silica nanoparticles can be produced through an alkoxysilane-based aqueous synthesis process without using water glass, which is a major cause of impurity contamination, thereby significantly improving the electrical reliability of the finally manufactured semiconductor device.

[0088] In addition, according to one embodiment of the present invention, by systematically controlling the step-by-step reaction conditions (pH, temperature, solvent composition, etc.) of core formation, core reinforcement, and shell formation, the structural characteristics of the core and shell can be clearly distinguished and formed, which enables the production of high-performance abrasive particles with only simple two-step reaction condition control without a complex shape control process.

[0089] Therefore, the manufacturing method of the present invention is advantageous for stably mass-producing high-quality core-shell silica nanoparticles with uniform particle size and structural characteristics and excellent reproducibility, as the process is relatively simple and easy to control. The effects of the present invention are not limited to those described above, and should be understood to include all effects that can be inferred from the composition of the invention described in the detailed description of the invention or the claims. Brief explanation of the drawing

[0091] Figure 1 is a schematic diagram showing a batch process for manufacturing silica nanoparticles according to the prior art. Figure 2 is a schematic diagram showing a semi-batch process for manufacturing silica nanoparticles according to the prior art. Figure 3 is a chemical reaction scheme showing the hydrolysis and condensation reactions of a TEOS (Tetraethyl orthosilicate) precursor. FIG. 4 is a schematic diagram to explain the principle of chemical mechanical polishing (CMP) and the concept of a core-shell structure that are the principles of the present invention. FIG. 5 is a schematic diagram of a synthesis process for silica nanoparticles according to one embodiment of the present invention. FIG. 6a is of a growth particle according to one embodiment of the present invention. 1 This shows the H-NMR spectrum. FIG. 6b is of a core particle according to one embodiment of the present invention. 1 This shows the H-NMR spectrum. FIG. 6c is of core-shell silica nanoparticles according to one embodiment of the present invention. 1 This shows the H-NMR spectrum. FIG. 7a is of a growth particle according to one embodiment of the present invention. 29 This shows the Si-NMR spectrum. FIG. 7b is of a core particle according to one embodiment of the present invention. 29This shows the Si-NMR spectrum. FIG. 7c is of core-shell silica nanoparticles according to one embodiment of the present invention. 29 This shows the Si-NMR spectrum. FIG. 8a is a 2D image showing the results of small-angle X-ray scattering (SAXS) analysis of a single particle according to a comparative example of the present invention. FIG. 8b is a 2D image showing the results of small-angle X-ray scattering (SAXS) analysis of core-shell silica nanoparticles according to one embodiment of the present invention. FIG. 9 is a 1D graph showing a comparison of small-angle X-ray scattering (SAXS) analysis results of a single particle [A] according to a comparative example of the present invention and a core-shell silica nanoparticle [B] according to one embodiment. FIG. 10a shows the results of dynamic light scattering (DLS) analysis of a grown particle according to one embodiment of the present invention. FIG. 10b shows the results of dynamic light scattering (DLS) analysis of a core-shell silica nanoparticle (regrowth) according to one embodiment of the present invention. FIG. 10c shows the results of dynamic light scattering (DLS) analysis of a core particle (water-substituted) according to one embodiment of the present invention. FIGS. 11a to 11d show scanning electron microscope (SEM) images of core-shell silica nanoparticles according to one embodiment of the present invention. Specific details for implementing the invention

[0092] The present invention will be described in more detail below. However, the present invention may be implemented in various different forms and is not limited by the embodiments described herein, and is defined only by the claims set forth below.

[0093] Additionally, the terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. Throughout the specification of this invention, the term 'comprising' any component means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0094] Throughout the specification, when it is stated that a part is "connected (connected, in contact, combined)" with another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members in between. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0095] The term “slurry composition” as used in this specification may refer to a slurry composition for polishing a target film, and the polishing may refer to Chemical Mechanical Polishing (CMP).

[0096] Unless otherwise noted, “%” as used in this specification may mean “weight%” or “wt%” in terms of content.

[0097] The terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise.

[0099] The first aspect of the present invention is,

[0100] The present invention provides a core-shell silica nanoparticle comprising: a core having a first Si-O-Si bonding structure; and a shell formed on the surface of the core and having a second Si-O-Si bonding structure, wherein the full width at half maximum (FWHM) of the peak exhibiting maximum intensity at 20° to 30° (2θ) during X-ray diffraction (XRD) analysis is 6.6° or less.

[0102] Hereinafter, silica nanoparticles according to the first aspect of the present invention will be described in detail. FIG. 1 is a schematic diagram illustrating a batch process for manufacturing silica nanoparticles according to the prior art. FIG. 2 is a schematic diagram illustrating a semi-batch process for manufacturing silica nanoparticles according to the prior art, and FIG. 3 is a chemical reaction equation showing the hydrolysis and condensation reactions of a TEOS (Tetraethyl orthosilicate) precursor. FIG. 4 is a schematic diagram to explain the principle of chemical mechanical polishing (CMP) and the concept of a core-shell structure, which are the principles of the present invention. FIG. 5 is a schematic diagram of a synthesis process for silica nanoparticles according to one embodiment of the present invention.

[0104] In one embodiment of the present invention, the first Si-O-Si bond structure and the second Si-O-Si bond structure may be similar or dissimilar in terms of physical properties such as bond regularity and density. Preferably, the first Si-O-Si bond structure may have a relatively more regular pattern, and the second Si-O-Si bond structure may have an irregular bond structure compared to the first Si-O-Si bond structure.

[0105] In one embodiment of the present invention, the core-shell silica nanoparticles can be manufactured according to the manufacturing method of the first aspect described above and feature a unique structure composed of a core and a shell having structurally different characteristics. The core region has a regular and dense Si-O-Si bonding structure to provide mechanical strength, while the shell region has an irregular and relatively less dense Si-O-Si bonding structure to enhance chemical reactivity. This structure can contribute to simultaneously improving the stability of abrasive particles and polishing efficiency in the CMP process.

[0106] In one embodiment of the present invention, the core may be obtained through steps (a) and (b) of the first aspect, namely, a wet growth step and a strengthening step. That is, the initial growth particles may be made into a denser and more stable structure through a strengthening process such as heat treatment and used as the core.

[0107] In one embodiment of the present invention, the structural characteristics of the core-shell silica nanoparticles can be characterized through X-ray diffraction (XRD) analysis. These characteristics may be important indicators reflecting the regularity and crystallinity of the atomic arrangement within the particles.

[0108] In one embodiment of the present invention, the structural characteristics of the core-shell silica nanoparticles can be evaluated by the Full Width at Half Maximum (FWHM) of the broad peak characteristic of amorphous silica appearing in the 2θ range (20° to 30°) during X-ray diffraction (XRD) analysis. The FWHM is a value representing the width of a peak, and generally tends to become wider as the crystallinity of the material decreases or the particle size becomes smaller. The FWHM of the core-shell silica nanoparticles may be 5.0° or greater, 5.5° or greater, 6.0° or greater, or 6.3° or greater, and may be 7.5° or less, 7.0° or less, or 6.6° or less. In particular, it may have a value of 6.6° or less. This may suggest that the particles obtained through the manufacturing method of the present invention possess a certain degree of structural regularity. If the value is below the above range, the crystallinity becomes excessively high, causing the intrinsic properties of silica to be lost or Polishing performance may be degraded. If the aforementioned range is exceeded, structural regularity may be too low, resulting in insufficient mechanical strength or instability during the CMP process.

[0109] In one embodiment of the present invention, the XRD pattern of the core-shell silica nanoparticles may appear as an overlap of amorphous peaks and crystalline peaks in a specific angle range. For example, a dominant amorphous peak of the silica may be observed in the range of 20° to 23° (2θ), and at the same time, a weak crystalline peak associated with a specific crystalline phase of the silica (e.g., cristobalite or similar structure) may be observed in the range of 26° to 28° (2θ). This may suggest that the reinforced core region of the present invention is partially crystallized or has a regular arrangement.

[0110] In one embodiment of the present invention, the peak positions observed in the XRD pattern can be converted into d-spacing values ​​using Bragg's law (nλ = 2d sinθ). This can serve as an indicator of the regularity of the internal structure of the grain.

[0111] In one embodiment of the present invention, the grown particle obtained after step (a) of the first aspect may have a d-spacing value according to Bragg's law of 3.80 Å or more, 3.85 Å or more, or 3.90 Å or more, and may have a value of 4.20 Å or less, 4.10 Å or less, or 4.05 Å or less. In particular, it may have a value of 3.90 Å or more and 4.05 Å or less.

[0112] In one embodiment of the present invention, the core obtained after step (b) of the first aspect may have a d-spacing value according to Bragg's law of 3.85 Å or more, 3.90 Å or more, or 3.95 Å or more, and may have a value of 4.20 Å or less, 4.10 Å or less, or 4.05 Å or less. In particular, it may have a value of 3.95 Å or more and 4.05 Å or less, which may be a range that is slightly increased or similar to that of the grown particle. This may mean that through the strengthening process, the Si-O-Si network becomes more regularly arranged or approaches a specific crystal structure.

[0113] In one embodiment of the present invention, the core-shell silica nanoparticles obtained after step (c) of the first aspect may have a d-spacing value according to Bragg's law of 3.85 Å or more, 3.90 Å or more, or 3.95 Å or more, and may have a value of 4.20 Å or less, 4.10 Å or less, or 4.05 Å or less. In particular, it may have a value of 3.95 Å or more and 4.05 Å or less, which may be a range similar to the d-spacing value of the core. This may suggest that the structural properties of the entire particle are mainly determined by the core. If the d-spacing is below the above range, the Si-O-Si bond distance is too short and may be structurally unstable. If it exceeds the above range, the bond distance is too long, resulting in low density and reduced mechanical strength.

[0114] In one embodiment of the present invention, the ratio of the relative intensity of the amorphous peak and the crystalline peak observed in the XRD pattern can be used as an indicator of the degree of regular structure within the particle.

[0115] In one embodiment of the present invention, the growth particle may have a ratio of the maximum intensity of the crystalline peak to the maximum intensity of the amorphous peak of 0.05 or more, 0.06 or more, or 0.07 or more, and may be 0.15 or less, 0.13 or less, or 0.12 or less. In particular, it may be in the range of 0.07 to 0.12.

[0116] In one embodiment of the present invention, the core may have a ratio of the maximum intensity of the crystalline peak to the maximum intensity of the amorphous peak of 0.08 or higher, 0.10 or higher, or 0.11 or higher, and may be 0.16 or lower, 0.14 or lower, or 0.13 or lower. In particular, it may be in the range of 0.11 to 0.13, which is slightly higher or similar to the level of the grown particle, indicating that regularity has slightly increased during the strengthening process.

[0117] In one embodiment of the present invention, the core-shell silica nanoparticles may have a ratio of the maximum intensity of the crystalline peak to the maximum intensity of the amorphous peak of 0.10 or higher, 0.12 or higher, or 0.13 or higher, and may be 0.20 or lower, 0.18 or lower, or 0.16 or lower. In particular, it may be in the range of exceeding 0.13 and 0.16 or lower, which may suggest that a structure contributing to the crystalline peak was additionally formed or influenced the change in peak shape during the shell formation process, at a higher ratio than the core. If the intensity ratio is below the above range, mechanical strength may be weak due to a lack of regular structure. If it exceeds the above range, crystallinity may become excessively high, leading to reduced polishing performance or changes in particle characteristics.

[0118] In one embodiment of the present invention, the degree of crosslinking or regularity of the Si-O-Si network within the particle can be quantified through the analysis of the peak area of ​​the XRD pattern. For example, the degree of crosslinking can be defined as (area of ​​the crystalline peak) / (area of ​​the amorphous peak + area of ​​the crystalline peak).

[0119] In one embodiment of the present invention, the growth particle may have a defined crosslinking rate of 3.0% or more, 3.5% or more, or 4.0% or more, 10.0% or less, 9.0% or less, or less than 8.0%. In particular, it may be 4.0% or more and less than 8.0%.

[0120] In one embodiment of the present invention, the core may have a defined crosslinking rate of 5.0% or more, 6.0% or more, or 7.0% or more, and may be 11.0% or less, 10.0% or less, or less than 9.0%. In particular, it may be 7.0% or more and less than 9.0%, which indicates that the degree of crosslinking has increased through a reinforcing process to a value higher than that of the growth particle.

[0121] In one embodiment of the present invention, the core-shell silica nanoparticles may have a defined crosslinking rate of 10.0% or more, 11.5% or more, or 12.5% ​​or more, or 20.0% or less, 18.0% or less, or 16.0% or less. In particular, it may be 12.5% ​​or more and 16.0% or less, which is a value significantly higher than that of the core, suggesting that shell formation contributes significantly to the calculation of the overall crosslinking rate. This may imply that the shell region has an irregular structure while locally crosslinked parts exist, or that the calculation results may vary depending on the peak separation method. If the crosslinking rate is below the above range, the particles may be weak due to insufficient network bonding. If it exceeds the above range, the structure may become excessively dense, leading to reduced reactivity or increased brittleness.

[0122] In one embodiment of the present invention, the full width at half maximum (FWHM) of the amorphous peak observed in the XRD pattern can also reflect the structural characteristics of the particle.

[0123] In one embodiment of the present invention, the growth particle may have a full width at half maximum (FWHM) of the amorphous peak of 5.5° or more, 6.0° or more, 7.5° or less, 7.0° or less, or 6.5° or less. In particular, it may be 6.5° or less.

[0124] In one embodiment of the present invention, the core may have a full width at half maximum (FWHM) of the amorphous peak of 5.0° or greater, 5.5° or greater, 6.5° or less, 6.3° or less, or less than 6.1°. In particular, it may be less than 6.1°, which is a value narrower than that of the grown grain, indicating that structural regularity has increased through a reinforcement process.

[0125] In one embodiment of the present invention, the core-shell silica nanoparticles may have a full width at half maximum (FWHM) of the amorphous peak of 5.5° or greater, 6.0° or greater, 7.0° or less, 6.8° or less, or less than 6.6°. In particular, it may be less than 6.6°, which is a range wider than the core and similar to or slightly narrower than the growth particle, suggesting that shell formation has influenced the overall peak shape. If the amorphous peak FWHM is below the above range, the particles may become excessively regular or crystallized, which may alter the polishing properties. If it exceeds the above range, the mechanical strength may be weak due to a lack of structural regularity.

[0126] In one embodiment of the present invention, the surface chemical properties of the core-shell silica nanoparticles are 1 It can be evaluated through H-NMR (proton nuclear magnetic resonance) analysis. These characteristics can be utilized to predict the surface reactivity of particles by analyzing the type and amount of hydroxyl groups, specifically silanol (Si-OH) groups, present on the particle surface.

[0127] In one embodiment of the present invention, the core-shell silica nanoparticles 1 When analyzing H-NMR, peaks attributed to silanol (Si-OH) groups on the silica surface may be observed in specific chemical shift ranges. For example, peaks may be observed in the ranges of 1.0 ppm to 1.2 ppm, 1.7 ppm to 1.9 ppm, and 3.4 ppm to 3.6 ppm, respectively. These peaks may correspond to surface hydroxyl groups in different environments, such as isolated silanol groups, vicinal silanols, geminal silanols, or hydrogen-bonded silanol groups, and their presence and relative intensity may affect the hydrophilicity, dispersibility, and chemical reactivity of the particles.

[0128] In one embodiment of the present invention, the Si-O-Si network density or bonding degree inside the core-shell silica nanoparticles 29 It can be quantitatively evaluated through Si-NMR (Silicon Nuclear Magnetic Resonance) analysis. These characteristics may be directly related to the mechanical strength and structural density of the particles.

[0129] In one embodiment of the present invention, the core (reinforced first region) is 29 The amount of Si-O-Si bonds per unit volume calculated based on the peak area corresponding to the Q4 structure (a state in which a Si atom is connected to four other Si atoms and oxygen atoms) during Si-NMR analysis is nm 3 5.5 x 10 per 4 or more, 6.0 x 10 4 or more, or 6.3 x 10 4 or it may be more, 7.5 x 10 4 or less, 7.2 x 10⁻⁶ 4 or less, or 7.0 x 10 4 It may be or less. In particular, 6.0 x 104 Up to 7.0 x 10 4 It could be a range. This means that a very dense network has been formed through the reinforcement process.

[0130] In one embodiment of the present invention, the core-shell silica nanoparticles 29 The amount of Si-O-Si bonds per unit volume in Si-NMR analysis is nm 3 2.8 x 10 per 4 or more, 3.0 x 10 4 or more, or 3.2 x 10 4 or it may be more, 4.5 x 10 4 or less, 4.2 x 10⁻⁶ 4 or less, or 4.0 x 10 4 It may be or less. In particular, 3.0 x 10 4 Up to 4.0 x 10 4 It may be within the range. This is a value lower than the core itself, suggesting that the presence of a relatively less dense shell region lowered the overall average value. The unit volume (nm) of the above core. 3 The amount of Si-O-Si bonds per ) is the unit volume (nm) of the core-shell silica nanoparticles. 3 The amount of Si-O-Si bonds may be 1.0 times or more, 1.1 times or more, or 1.2 times or more, 4.0 times or less, 3.5 times or less, or 3.0 times or less. In particular, it may be in the range of 1.2 to 3.0 times. This ratio can serve as an indicator that quantitatively represents the difference in structural density between the core and the shell. If the amount of Si-O-Si bonds is less than the above range, the mechanical strength of the particles may be insufficient. If it exceeds the above range, the particles may become excessively dense, resulting in reduced reactivity or increased brittleness.

[0131] In one embodiment of the present invention, the above 1H-NMR analysis results can be used to quantify the amount of effective hydroxyl groups (effective OH) present on the particle surface or within accessible pores. This is an important indicator related to the surface reactivity of the particles and their ability to chemically interact during the CMP process. Effective OH is a value related to surface area (roughness) and can be defined as “effective OH per particle” or “effective OH on the particle surface.”

[0132] In one embodiment of the present invention, the growth particle (after step (a) of the first aspect) is 1 When analyzed by H-NMR, the amount of effective hydroxyl groups (effective OH) on the particle surface is 4.0 x 10⁶ per gram. 6 or more, 5.0 x 10 6 or more, or 5.5 x 10 6 or it may be more, 10.0 x 10 6 or less, 9.0 x 10⁻⁶ 6 or less, or 8.0 x 10 6 It may be or less. In particular, 5.5 x 10 6 Up to 8.0 x 10 6 It can be a range.

[0133] In one embodiment of the present invention, the core (after step (b) of the first side) is 1 When analyzed by H-NMR, the amount of effective hydroxyl groups (effective OH) on the particle surface is 6.0 x 10⁶ per gram. 5 or more, 7.5 x 10 5 or more, or 8.5 x 10 5 or it may be more, 1.5 x 10 6 or less, 1.2 x 10⁻⁶ 6 or less, or 1.0 x 10⁻⁶ 6 It may be or less. In particular, 8.5 x 10 5 Up to 1.0 x 10 6It may be within the range. This is a significantly reduced value compared to the grown particles, meaning that surface and internal hydroxyl groups were removed through the strengthening process by condensing to form Si-O-Si bonds.

[0134] In one embodiment of the present invention, the core-shell silica nanoparticles 1 When analyzed by H-NMR, the amount of effective hydroxyl groups (effective OH) on the particle surface is 8.0 x 10⁶ per gram. 5 or more, 9.5 x 10 5 or more, or 1.05 x 10⁻⁶ 6 or it may be more, 1.8 x 10 6 or less, 1.5 x 10⁻⁶ 6 or less, or 1.2 x 10⁻⁶ 6 It may be or less. In particular, 1.05 x 10 6 Up to 1.2 x 10 6 It may be within a range. This is a higher value than that of the core itself, indicating that the chemically highly active shell region provides additional effective hydroxyl groups. The amount of effective hydroxyl groups (effective OH) on the particle surface of the core-shell silica nanoparticles may be 1.0 times or more, 1.03 times or more, or 1.05 times or more, 2.0 times or less, 1.8 times or less, or 1.5 times or less than the amount of effective hydroxyl groups (effective OH) on the particle surface of the core. In particular, it may be in the range of 1.05 to 1.5 times. This ratio quantitatively demonstrates that surface reactivity has increased through shell formation. If the amount of effective hydroxyl groups is below the above range, the chemical reactivity of the particles is low, which may result in reduced CMP efficiency. If it exceeds the above range, the stability of the particles may decrease or the dispersibility within the slurry may deteriorate.

[0135] In one embodiment of the present invention, the size and internal structure of the core-shell silica nanoparticles can be evaluated through small-angle X-ray scattering (SAXS) analysis. SAXS provides nanometer-scale structural information and is useful for analyzing the average size, shape, internal density distribution, etc. of the particles.

[0136] In one embodiment of the present invention, the core may have an average diameter measured during SAXS analysis of 35 nm or more, 45 nm or more, or 50 nm or more, 70 nm or less, 65 nm or less, or 60 nm or less. In particular, it may be in the range of 50 nm to 60 nm.

[0137] In one embodiment of the present invention, the shell may have an average thickness measured during SAXS analysis of 8 nm or more, 10 nm or more, or 12 nm or more, 25 nm or less, 20 nm or less, or 18 nm or less. In particular, it may be in the range of 12 nm to 18 nm.

[0138] In one embodiment of the present invention, the core-shell silica nanoparticles may have an average diameter of 50 nm or more, 60 nm or more, or 65 nm or more as measured by SAXS analysis, or 90 nm or less, 80 nm or less, or 75 nm or less. In particular, it may be in the range of 65 nm to 75 nm. If the particle size and thickness are below the above range, it may be difficult to obtain a sufficient mechanical polishing effect required for the CMP process. If the above range is exceeded, the risk of causing defects such as scratches on the surface to be polished increases, or the dispersion stability of the slurry may decrease.

[0139] In one embodiment of the present invention, the SAXS analysis results of the core-shell silica nanoparticles may show a characteristic change in absolute intensity within a specific scattering vector (q) range. For example, when the scattering vector (q) is 2.5 nm -1 to 9.0 nm -1 In the range (Section 1), the scattering intensity may exhibit a pattern of decreasing inversely proportional to powers of q, which can reflect information related to the overall shape and surface structure of the particle. In the case of a core-shell structure, the slope of the scattering intensity decrease or the absolute intensity value in this region may differ compared to a single particle, and the scattering intensity may be weakened, particularly due to a decrease relative to electron density.

[0140] In one embodiment of the present invention, the SAXS analysis results of the core-shell silica nanoparticles may show peaks related to the internal structure in a higher scattering vector (q) range. For example, when the scattering vector (q) is 12 nm -1 to 17 nm -1 A peak exhibiting maximum intensity can be observed in the range (Section 2). The position and shape of this peak may be related to the short-range regularity or average interatomic distance of the Si-O-Si network structure inside the core or shell, and the peak position or intensity may change compared to a single particle depending on the formation of the core-shell structure.

[0141] In one embodiment of the present invention, the hydrodynamic size and size distribution of the core-shell silica nanoparticles can be measured by Dynamic Light Scattering (DLS). DLS analyzes the Brownian motion of particles in solution to provide the average particle size and the Polydispersity Index (PDI).

[0142] In one embodiment of the present invention, the growth particle may have an average diameter measured by DLS of 40 nm or more, 50 nm or more, or 55 nm or more, and may be 80 nm or less, 75 nm or less, or 68 nm or less. In particular, it may be in the range of 55 nm to 68 nm.

[0143] In one embodiment of the present invention, the core may have an average diameter measured by DLS of 35 nm or more, 45 nm or more, or 50 nm or more, 75 nm or less, 68 nm or less, or 62 nm or less. In particular, it may be in the range of 50 nm to 62 nm. This may suggest that there was slight shrinkage or surface change during the reinforcement process, as the size is slightly reduced or similar to that of the grown particles.

[0144] In one embodiment of the present invention, the core-shell silica nanoparticles may have an average diameter measured by DLS of 45 nm or more, 55 nm or more, or 60 nm or more, 90 nm or less, 80 nm or less, or 75 nm or less. In particular, it may be in the range of 60 nm to 75 nm. This indicates that a shell layer is formed with an increased size compared to the core. If the average diameter is below the DLS average diameter range, the particles are too small, and the polishing efficiency may be low. If it exceeds the above-mentioned range, the risk of scratching increases and dispersion stability may be reduced.

[0145] In one embodiment of the present invention, the core may have a polydispersity index (PDI) measured by DLS on core particles only, which is 0.12 or less, 0.10 or less, or 0.08 or less. In particular, it may have a low value of 0.08 or less. This means that the particle size distribution has become very uniform through the reinforcement process.

[0146] In one embodiment of the present invention, the core-shell silica nanoparticles may have a PDI measured by DLS of 0.06 or higher, 0.07 or higher, or 0.08 or higher, or 0.20 or lower, 0.18 or lower, or 0.15 or lower. In particular, it may be in the range of 0.08 or higher and 0.15 or lower. This indicates that the PDI is slightly increased compared to the core itself, suggesting that the size distribution has widened slightly during the shell formation process, but still maintains a relatively uniform distribution. If the above-described range is exceeded, the particle size distribution widens, which may reduce the predictability and uniformity of the CMP process and increase the risk of scratching.

[0147] In one embodiment of the present invention, the actual dry size of the core-shell silica nanoparticles can be measured using a scanning electron microscope (SEM). Unlike DLS, SEM directly observes the physical size of the particles and is therefore not affected by the hydration layer.

[0148] In one embodiment of the present invention, the core-shell silica nanoparticles may have an average diameter measured by SEM of 35 nm or more, 40 nm or more, or 45 nm or more, or 85 nm or less, 75 nm or less, or 70 nm or less. In particular, it may be in the range of 45 nm to 70 nm. If the average diameter is less than the above SEM average diameter range, the particles are too small and the polishing effect may be negligible. If it exceeds the above range, the possibility of causing scratches may increase.

[0149] In one embodiment of the present invention, the average diameter of the core-shell silica nanoparticles measured by SEM may be smaller than the average diameter measured by DLS. For example, the SEM average diameter may be 3 nm or more, 4 nm or more, or 5 nm or more smaller than the DLS average diameter, or 30 nm or less, 25 nm or less, or 20 nm or less smaller. In particular, it may have a value of 5 nm to 20 nm smaller. This difference may occur because DLS measurements include the hydration layer or electrical double layer surrounding the particle to measure the size, whereas SEM measures the size of the particle itself dried in a vacuum. Additionally, the effect of the irregular shell region shrinking during the drying process, which reduces the actual size, may also contribute.

[0150] In one embodiment of the present invention, the ratio of the shell thickness to the core diameter of the core-shell silica nanoparticles may affect the overall structural characteristics and polishing performance of the particles. The core-shell silica nanoparticles may have a shell / core thickness ratio of 0.10 or higher, 0.13 or higher, or 0.15 or higher, and may have a shell / core thickness ratio of 0.75 or lower, 0.60 or lower, or 0.5 or lower. In particular, they may have a shell / core thickness ratio of 0.15 or higher and 0.5 or lower. If the ratio is lower than the above range, the shell region may be too thin, resulting in a negligible effect on improving chemical reactivity. If the above range is exceeded, the core region may become relatively smaller, leading to insufficient mechanical strength or reduced overall stability of the particles.

[0152] The second aspect of the present invention is,

[0153] A method for manufacturing the above-mentioned core-shell nanoparticles is provided.

[0155] Detailed explanations have been omitted for parts that overlap with the first aspect of the present invention, but the content described in the first aspect of the present invention may be applied equally even if such explanations are omitted in the second aspect.

[0157] Hereinafter, a method for manufacturing core-shell silica nanoparticles according to the second aspect of the present invention will be described in detail.

[0159] A manufacturing method according to one embodiment of the present invention may aim to produce silica nanoparticles with a dual structure composed of a core (first region) and a shell (second region) having different structural characteristics. Such a structure can contribute to improving chemical mechanical polishing (CMP) performance by simultaneously optimizing the mechanical strength and chemical reactivity of the final polished particles.

[0160] First, in one embodiment of the present invention, a step (step (a)) of forming a first region including a first Si-O-Si bond structure through a condensation reaction of a silicon precursor under a first pH condition may be included. This step is a process of forming a core region that constitutes the center of the final particle, and may be intended to secure the mechanical strength of the particle by forming a relatively regular and dense silica network structure. This regular structure may serve to help the particle maintain a stable shape without being destroyed even under polishing pressure during a subsequent CMP process.

[0161] In one embodiment of the present invention, the first pH condition of step (a) can be controlled using a basic catalyst. The basic catalyst can promote the hydrolysis and condensation reactions of the silicon precursor, and although its type is not particularly limited, any one selected from the group consisting of ammonia water, sodium hydroxide, potassium hydroxide, triethylamine, and ethylenediamine may be used. Preferably, the pH can be controlled using ammonia water, which may have the advantage of facilitating the removal of residues after the reaction.

[0162] In one embodiment of the present invention, the first pH condition of step (a) may be 7.5 or higher, 8.0 or higher, 8.5 or higher, or 9.0 or higher, or 11.0 or lower, 10.5 or lower, or 10.0 or lower. In particular, it may be performed in the pH range of 7.5 to 10.0. If it is below the above range, the condensation reaction rate may be too slow, resulting in reduced productivity or non-uniform particle growth. If it exceeds the above range, the reaction rate may become excessively fast, leading to reduced regularity of the silica network or aggregation between particles, making it difficult to ensure uniformity and strength of the core structure.

[0163] In one embodiment of the present invention, step (a) may be performed under specific temperature conditions. The first temperature condition may be 60°C or higher, 70°C or higher, 75°C or higher, or 80°C or higher, 100°C or lower, 95°C or lower, or 90°C or lower. In particular, it may be performed under a first temperature condition of 80°C to 90°C. If the temperature is below the above range, the reaction rate may be slow and productivity may be low, and if the temperature exceeds the above range, reaction control may become difficult or side reactions may increase, which may reduce the uniformity of the core structure.

[0164] In one embodiment of the present invention, the silicon precursor may be used without limitation as long as it is a compound capable of forming a silica network. For example, an alkoxysilane-based compound may be used, specifically, tetraalkoxysilanes such as tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), tetrapropoxysilane, and tetrabutoxysilane, or alkoxysilanes containing organic functional groups such as methyltriethoxysilane (MTES), methyltrimethoxysilane (MTMS), vinyltriethoxysilane, and phenyltriethoxysilane may be used alone or in a mixture of two or more types. Considering reactivity, cost-effectiveness, and ease of handling, tetraethoxysilane (TEOS) may preferably be used.

[0165] In one embodiment of the present invention, step (a) may be performed in a semi-batch manner in which a silicon precursor is gradually introduced into a reaction solution (mother liquor). This is intended to improve the uniformity of the final particle size by separating and controlling the initial nucleation and subsequent particle growth of the reaction. In particular, a hydrolysis solution containing a silicon precursor may be introduced using a metering pump or the like, and a strategy of gradually increasing the introduction rate over time may be used. For example, the introduction rate may be gradually increased relative to the initial rate to maintain a constant growth rate per unit time as the surface area of ​​the particles increases. Such control of the introduction rate can help maintain a narrow particle size distribution while shortening the overall reaction time.

[0166] In one embodiment of the present invention, the method may include a step of performing hydrolysis of a silicon precursor prior to step (a). That is, it may further include a step of preparing a hydrolysis solution by mixing water, an acid catalyst, and the silicon precursor. This may serve to help the condensation reaction in the basic mother liquor proceed more uniformly and predictably by converting the silicon precursor into a monomer or oligomer form containing a highly reactive silanol (Si-OH) group in advance. As the acid catalyst, conventional inorganic acids such as nitric acid, hydrochloric acid, or sulfuric acid, or organic acids such as acetic acid may be used; preferably, nitric acid (HNO3), which is easy to remove after the reaction, may be used. The concentration of the silicon precursor in the hydrolysis solution may be 15% or more, 20% or more, or 25% or more, 55% or less, 50% or less, or 45% or less. In particular, it may be controlled within the range of 25% to 45%. If the concentration is too low, the reaction efficiency may decrease, and if it is too high, hydrolysis may proceed unevenly or gelation may occur.

[0167] In one embodiment of the present invention, the step of preparing a mother liquor to perform the reaction prior to step (a) may be included. That is, the step of preparing a reaction mother liquor by adding a basic catalyst to water (preferably deionized water) may be further included. This is to form and maintain the first pH condition described in step (a).

[0168] Next, in one embodiment of the present invention, the method may include a step ((b)) of raising the temperature of the reaction solution in which the first region is formed to a second temperature condition higher than the first temperature condition to strengthen the Si-O-Si bonding structure of the first region. This step is intended to make the internal structure of the core region formed in step (a) more dense and to strengthen the network bonding to improve mechanical strength. This core strengthening process can play an important role in ensuring core stability in the subsequent shell formation step and enabling the final particles to withstand mechanical stress applied during the CMP process.

[0169] In one embodiment of the present invention, the second temperature condition of step (b) may be 80°C or higher, 85°C or higher, or 90°C or higher, 120°C or lower, 110°C or lower, or 105°C or lower. In particular, it may be set to a range of 90°C to 105°C. This is a temperature higher than the first temperature condition of step (a) (e.g., 80°C), which may be effective in further promoting the condensation reaction of residual OH groups in the silica network and inducing structural rearrangement to form a more stable Si-O-Si bond structure. If the temperature is too low, the strengthening effect may be negligible, and if the temperature is excessively high, side effects such as rapid growth or aggregation of particles or boiling of the reaction solvent may occur.

[0170] In one embodiment of the present invention, the time for performing step (b) may be 1 hour or more, 1.5 hours or more, or 2 hours or more, 8 hours or less, 7 hours or less, or 6 hours or less. In particular, it may be performed for 2 to 6 hours. By performing heat treatment for a sufficient amount of time, the strengthening effect of the internal structure of the core can be maximized. If the time is too short, the strengthening may be insufficient, and if it is too long, productivity may be reduced.

[0171] In one embodiment of the present invention, step (b) may be performed while maintaining the solid content concentration of the reaction solution at a level below a certain level. For example, the solid content concentration may be maintained at 20% or less. This may be done to prevent excessive aggregation or gelation between particles during the heat treatment process and to ensure that each particle is reinforced independently and uniformly. If necessary, the concentration may be adjusted by adding a solvent (e.g., water) during the reinforcement step.

[0172] Next, in one embodiment of the present invention, the method may include the step ((c)) of adding an alcohol to a reaction solution containing a reinforced first region and further proceeding with a condensation reaction of the silicon precursor to form a second region containing a second Si-O-Si bond structure on the surface of the first region. This step is a process of forming a chemically active shell region on the reinforced core surface. The irregular Si-O-Si bond structure of the shell region may contain a relatively large number of surface silanol (Si-OH) groups or structural defects, which may serve to increase reactivity with chemical additives in the slurry or chemical interaction with the film to be polished during the CMP process.

[0173] In one embodiment of the present invention, the addition of alcohol in step (c) may be intended to change the polarity and solvent composition of the reaction environment to influence the rate and mechanism of the subsequent condensation reaction. The addition of alcohol may affect the solubility and hydrolysis equilibrium of the silicon precursor and, under basic catalytic conditions, control the condensation reaction rate to induce the formation of a more irregular and less dense silica network structure (shell) different from that during core formation. The alcohol may be any lower alcohol available in the art, without limitation, and may be, for example, any one selected from the group consisting of methanol, ethanol, propanol, isopropanol, and butanol, or a mixture thereof. In particular, when ethanol is used, reaction control may be easy and economical.

[0174] In one embodiment of the present invention, the amount of alcohol added in step (c) may be controlled based on the total volume of the reaction solution. For example, it may be 1 / 7 or more, 1 / 6 or more, or 1 / 5 or more of the total volume of the reaction solution, or 1 / 2 or less, 1 / 2.5 or less, or 1 / 3 or less. In particular, it may be added in an amount corresponding to 1 / 5 to 1 / 3 of the total volume of the reaction solution. If the amount of alcohol added is too small, the effect on the shell structure formation mechanism may be negligible, and if it is too large, the stability of the reaction solution may be reduced or the solubility of the silicon precursor may change excessively, making it difficult to form a uniform shell.

[0175] In one embodiment of the present invention, after adding alcohol in step (c), it may be preferable to undergo a stabilization step for a certain period of time before proceeding with an additional condensation reaction. For example, a stabilization step may be additionally included for 15 minutes or more, 20 minutes or more, or 30 minutes or more. This may serve to help the subsequent shell formation reaction proceed more stably and uniformly by ensuring that the added alcohol is uniformly mixed within the reaction solution and that the core particle surface and the solution environment reach equilibrium under new conditions.

[0176] In one embodiment of the present invention, the condensation reaction of step (c) may be carried out under specific pH conditions. For example, the pH may be 7.5 or higher, 7.8 or higher, or 8.0 or higher, 10.0 or lower, 9.5 or lower, or 9.0 or lower. In particular, it may be carried out under pH conditions of 8.0 to 9.0. This may be a range similar to, slightly higher or lower than, the pH conditions of the core formation step (step (a)), and may be suitable for controlling the condensation rate of the silicon precursor in an environment with added alcohol to induce the formation of a shell of an irregular structure.

[0177] In one embodiment of the present invention, the input rate of the silicon precursor introduced for shell formation in step (c) may be controlled differently from the input rate in the core formation step (step (a)). For example, the input rate in step (c) may be set faster than the final input rate in step (a). This may be intended to increase the reaction rate to form a shell layer in a relatively short time and to induce the formation of a less regular silica network due to the rapid condensation rate.

[0179] The third aspect of the present invention is,

[0180] A method for preparing a chemical mechanical polishing composition is provided, comprising the step of dispersing the core-shell silica nanoparticles in a solvent.

[0182] Detailed explanations have been omitted for parts that overlap with the first and second aspects of the present invention; however, the contents described for the first and second aspects of the present invention may be applied equally to the third aspect even if such explanations are omitted.

[0184] Hereinafter, a method for manufacturing a chemical mechanical polishing composition according to the third aspect of the present invention will be described in detail.

[0186] First, in one embodiment of the present invention, a step of manufacturing core-shell silica nanoparticles according to the first aspect may be included. This step is a process of securing high-performance abrasive particles, which are a core component of the present invention. Since the method of manufacturing and the characteristics of the core-shell silica nanoparticles have been described above, a detailed description will be omitted.

[0187] Next, in one embodiment of the present invention, the method may include a step of dispersing the manufactured core-shell silica nanoparticles in a solvent. This step is a process of uniformly dispersing the manufactured abrasive particles in a liquid medium to form a final slurry-type composition. The solvent is not particularly limited as long as it can stably disperse the abrasive particles and is suitable for the CMP process, but generally, high-purity deionized water (DIW) may be primarily used. Conventional dispersion methods such as stirring and ultrasonic treatment may be used during the dispersion process, and if necessary, a dispersant or surfactant may be additionally added to improve dispersion stability. Furthermore, depending on the application of the final CMP composition and the type of film to be polished, various additives such as pH adjusters, oxidizers, corrosion inhibitors, and polishing rate enhancers may be added in the dispersion step or subsequent steps, and these may be appropriately selected and combined within the scope of conventional CMP slurry manufacturing techniques known in the art.

[0189] The fourth aspect of the present invention is,

[0190] A chemical mechanical polishing composition comprising the above-mentioned core-shell silica nanoparticles; and a solvent is provided.

[0192] Detailed descriptions of parts overlapping with the first to third aspects of the present invention have been omitted; however, the descriptions of the first to third aspects of the present invention may be applied equally to the fourth aspect even if such descriptions are omitted.

[0194] Hereinafter, a chemical mechanical polishing composition according to the fourth aspect of the present invention will be described in detail.

[0196] In one embodiment of the present invention, the chemical mechanical polishing composition is characterized by including the core-shell silica nanoparticles of the second aspect described above as polishing particles. The detailed structure and characteristics of the core-shell silica nanoparticles have been described above and will therefore be omitted. Polishing particles of such a unique structure can play a key role in providing excellent polishing performance and low surface defects during the CMP process.

[0197] In one embodiment of the present invention, the composition comprises a solvent for dispersing the core-shell silica nanoparticles. The solvent may generally be water, particularly high-purity deionized water (DIW) suitable for semiconductor processes, but may also partially include other water-soluble solvents such as alcohol as necessary.

[0198] In one embodiment of the present invention, the content of core-shell silica nanoparticles in the composition can be appropriately adjusted according to the polishing target, the required polishing rate and surface quality, etc., and may be, for example, in the range of 0.1 wt% to 30 wt% based on the total weight of the composition.

[0199] In one embodiment of the present invention, the composition may additionally include various additives to optimize CMP performance as needed. For example, dispersants to maintain particle dispersion stability (e.g., polyacrylic acid-based, surfactant, etc.), pH adjusters to adjust the pH of the composition to a specific range (e.g., acidic, neutral, or basic) (e.g., nitric acid, potassium hydroxide, ammonia, etc.), oxidizers to help form an oxide film during metal film polishing (e.g., hydrogen peroxide, etc.), corrosion inhibitors to inhibit corrosion of metal wiring (e.g., benzotriazole, etc.), and additives to control the polishing rate or selectivity ratio may be included without limitation. The types and amounts of such additives may be selected to suit the polishing target and process conditions based on ordinary knowledge known in the art.

[0201] The fifth aspect of the present invention is,

[0202] A method for manufacturing a semiconductor device is provided, comprising the step of polishing a metal or semiconductor film using the above chemical mechanical polishing composition.

[0204] Detailed descriptions of parts overlapping with the first to fourth aspects of the present invention have been omitted, but the descriptions of the first to fourth aspects of the present invention may be applied equally to the fifth aspect even if such descriptions are omitted.

[0206] Hereinafter, a method for manufacturing a semiconductor device according to the fifth aspect of the present invention will be described in detail.

[0208] A method for manufacturing a semiconductor device according to one embodiment of the present invention includes a polishing step using a chemical mechanical polishing composition of the fourth aspect described above as a process step for planarizing or removing a specific film formed on a wafer.

[0209] First, in one embodiment of the present invention, a metal or semiconductor film may be formed on a semiconductor substrate (wafer) to be polished. The metal film may be various metals used for forming wiring or barrier layers, such as copper (Cu), tungsten (W), aluminum (Al), titanium (Ti), and tantalum (Ta), and the semiconductor film may be various films used for insulation, passivation, gate electrodes, etc., such as silicon oxide (SiO2) film, silicon nitride (SiN) film, and polysilicon (Poly-Si) film. The film may have a single-layer or multi-layer structure, and it may be required to flatten the surface by removing the step difference or removing it to a specific thickness through a CMP process.

[0210] Next, in one embodiment of the present invention, the chemical mechanical polishing composition of the fourth aspect is prepared and supplied between the surface of the semiconductor substrate on which the polishing target film is formed and the polishing pad.

[0211] Next, in one embodiment of the present invention, mechanical friction is generated by applying a constant pressure (down force) while rotating the polishing pad and the semiconductor substrate relative to each other with the composition supplied. Simultaneously, chemical components within the composition react with the surface of the film to be polished, thereby altering or dissolving the surface layer. Due to the combined effect of these chemical and mechanical actions, the film to be polished is gradually removed and the surface is flattened.

[0212] At this time, the core-shell silica nanoparticles of the present invention included in the composition provide stable mechanical polishing ability due to the reinforced core, while simultaneously playing a role in promoting chemical reactions or increasing polishing efficiency through the activated shell surface.

[0213] The above polishing step can be performed using conventional CMP equipment, and process variables such as polishing pressure, pad and wafer rotation speed, slurry supply speed, and polishing time can be appropriately set by a person skilled in the art according to the type of film to be polished, target polishing amount, required surface quality, etc.

[0214] After the above polishing step is completed, polishing particles and byproducts remaining on the wafer surface are generally removed through a cleaning process. This CMP process can be repeatedly applied in various stages of semiconductor device manufacturing, such as interlayer insulating film planarization, metal wiring formation (damascene process), and shallow trench isolation (STI), and the chemical mechanical polishing composition of the present invention can provide excellent performance in these various CMP applications.

[0216] Hereinafter, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0218] Preparation Example 1: Preparation of hydrolysate

[0219] Tetraethoxysilane (TEOS) was used as a silicon precursor. An acid catalyst was first added to deionized water (DIW) at a ratio of 1 g of nitric acid (HNO3) per 1,000 g of DIW, and the mixture was thoroughly mixed. Subsequently, TEOS was added while maintaining the temperature of the DIW at no more than 40°C. The amount of TEOS was adjusted so that the concentration of TEOS in the total solution was in the range of 30–40%. The mixture was stirred using a stirrer at room temperature for 1 hour to prepare a hydrolyzed solution. The prepared hydrolyzed solution was stirred until addition to maintain a homogeneous state.

[0221] Preparation Example 2: Preparation of Reaction Mother Liquor

[0222] DIW was introduced into the reactor, and a small amount of water ammonia was added as a basic catalyst to adjust the pH to a range of 8.5 to 9.8. Care was taken not to exceed 10. The prepared mother liquor was stabilized by stirring for at least 30 minutes.

[0224] Preparation Example 3: Preparation of growth particles (first region)

[0225] The reaction mother liquor prepared in Preparation Example 2 was maintained at 85°C in a reactor and stirred at 180 RPM. The hydrolysate prepared in Preparation Example 1 was introduced into the reaction mother liquor using a metering pump. The initial injection rate was set to 4 ml / min, and as the reaction proceeded, the injection rate was increased stepwise to 7 ml / min, 10 ml / min, and finally to 13 ml / min, taking into account particle growth. The total injection time was approximately 8 hours. During the reaction, diluted ammonia water (DIW:ammonia water = 3:1 volume ratio) was periodically injected to maintain the pH of the solution within the range of 7.5 to 8.8. After the injection of the hydrolysate was completed, a stabilization step was performed by stirring at 85°C for an additional hour to obtain a suspension of grown particles (Region 1). The average diameter of the obtained grown particles was approximately 35 nm.

[0227] Preparation Example 4: Preparation of the core (reinforced first region)

[0228] The temperature of the growth particle suspension obtained in Preparation Example 3 above was raised to 100°C to proceed with the core strengthening step. During this process, DIW was periodically replenished to ensure that the solid content concentration did not exceed 18% due to solvent evaporation. The pH of the reaction solution was maintained at room temperature at 7.0 or higher, preferably in the range of 7.5 to 8.8. The strengthening step was performed at 100°C for a total of 2 hours. After the strengthening step, the average diameter of the particles decreased slightly to approximately 33 nm. After strengthening, the reaction solution was cooled to 85°C and stabilized for 1 hour. Subsequently, ethanol (EtOH) was slowly added using a metering pump at a rate of 10 ml / min or less, in an amount equivalent to approximately 1 / 4 of the total volume of the reaction solution. After adding EtOH, the solution was further stabilized at 85°C for 30 minutes to obtain the core (strengthened first region) suspension.

[0230] Example 1: Preparation of Core-Shell Silica Nanoparticles

[0231] The shell formation step was carried out by maintaining the core suspension obtained in Preparation Example 4 at 85°C and 180 RPM while adding the hydrolysate from Preparation Example 1 at a rate of 18 ml / min. During the shell formation step, the pH was maintained in the range of 8.5 to 8.8. Shell formation was completed by adding the hydrolysate for approximately 2 hours. After the reaction was finished, stirring was continued while slowly cooling the reactor to room temperature to obtain the final core-shell silica nanoparticle suspension. The average diameter of the obtained core-shell particles was approximately 40 nm.

[0233] Reference Example 1: Growth Particles

[0234] To examine the characteristics of the growth particles prepared according to the method of Preparation Example 3 above, a suspension was used as Reference Example 1.

[0236] Reference Example 2: Core Particle

[0237] The core particle suspension prepared according to the method of Preparation Example 4 above was used as Reference Example 2.

[0239] Comparative Example 3: Competitor's silica nanoparticles

[0240] A commercial silica particle product for CMP slurry from Nalco was prepared as Comparative Example 3.

[0242] Experimental Example 1: Dynamic Light Scattering (DLS) Analysis Results

[0243] (1) Measurement method

[0244] Particle suspensions from Preparation Example 3 (Reference Example 1), Preparation Example 4 (Reference Example 2), Example 1, and Comparative Example 3 were each collected, and diluted samples were prepared using DIW based on a particle concentration of 5%. For each diluted sample, a Dynamic Light Scattering (DLS) instrument (Model Name: Nano Zs , manufacturing company: Malvern The mean size (Z-average) and polydispersity index (PDI) of the particles were measured at 25°C using ). Measurements were performed for each sample 3 The average value was used after performing the procedure several times.

[0246] (2) Measurement results

[0247] The measurement results are shown in Table 1 and Figures 10a to 10c below.

[0249] Particle separation Average diameter (nm) [Z-Average] PDI Growth particles (Reference Example 1) 62.12 (Sample No. 923) 0.094 Core particles (Reference Example 2) 59.84 (Sample No. 803) 0.052 Core-Shell (Example 1) 67.74 (Sample No. 841) 0.109 Nalco (Comparative Example 3) 40.60 (Sample No. 4) 0.096

[0251] The average diameter of the growth particle (Reference Example 1) was 62.12 nm, and the core particle (Reference Example 2), which underwent a core reinforcement step, had a size that was slightly reduced to 59.84 nm. This satisfies the specific range (50 nm to 62 nm) of the present invention. In addition, the PDI of the core particle was 0.052, which is significantly lower than the PDI of the growth particle (0.094), confirming that the particle size distribution became very uniform. This supports the technical content presented in the present invention (reduction of PDI, PDI ≤ 0.08). Subsequently, the average diameter of the core-shell particle (Example 1), which underwent a shell formation step, increased to 67.74 nm, which satisfies the configuration range (60 nm to 75 nm) of the present invention. The PDI of the core-shell particle was 0.109, which is slightly higher than that of the core particle, but it is within the configuration range (0.08 or more and 0.15 or less) of the present invention, indicating that a relatively uniform size distribution is maintained. Comparative Example 3 (Nalco) particles were measured to have an average diameter of 40.60 nm and a PDI of 0.096.

[0253] Experimental Example 2: X-ray Diffraction (XRD) Analysis Results

[0254] (1) Measurement method

[0255] X-ray diffraction (XRD) analysis was performed on powder samples obtained by drying the particle suspensions of Comparative Example 1, Comparative Example 2, Example 1, and Comparative Example 3. The analysis instrument used was a SmartLab model from Rigaku, and scans were performed at intervals of 0.02° in the range of 10° to 35° (2θ) using Cu Kα radiation. From the obtained diffraction patterns, the peak position (2θ), full width at half maximum (FWHM), peak intensity, and peak area were analyzed. The d-spacing value was calculated from the peak position using Bragg's law (nλsinθλ=1.5406 Å), and the peaks were separated into an amorphous peak (2θ ≈ 20-23°) and a crystalline peak (2θ ≈ 26-28°) to calculate the relative intensity ratio and the crosslinking rate [(crystalline peak area) / (amorphous peak area + crystalline peak area)].

[0257] (2) Measurement results

[0258] The XRD analysis results are summarized in Table 2 below.

[0260] Particle separation d-spacing (Å) @≒22° d-spacing (Å) @≒27° Rel. Int. (%) (I@27° / I@22°) Area (Amorphous) Area (Crystalline) Bridge rate (%) FWHM (°) @≒22° Growth particles (Reference Example 1) 3.98 3.26 8.26 38209 1933 4.82 6.2 Core particles (Reference Example 2) 4.02 3.28 12.13 30972 2809 8.3 5.9 Core-Shell (Example 1) 4.03 3.27 14.18 38123 5319 12.25 6.3 Nalco (Comparative Example 3) 4.06 3.34 12.4 23098 2307 9.09 6.7

[0262] In all samples, a typical amorphous silica peak (2θ ≈ 22°) and a weak crystalline peak (2θ ≈ 27°) were observed, satisfying the range configuration presented herein.

[0263] The amorphous peak d-spacing of the grown particle (Reference Example 1) was 3.98 Å, satisfying the range (3.90-4.05 Å) presented herein. The core particle (Reference Example 2) was 4.02 Å, and the core-shell particle (Example 1) was 4.03 Å, satisfying the range (3.95-4.05 Å) presented herein. This is a slightly smaller value than that of the Nalco particle (4.06 Å).

[0264] The ratio of relative intensity of the crystalline peaks increased from the growth particles (8.26%) to the core particles (12.13%), and further increased in the core-shell particles (14.18%). The ratio of growth particles satisfies the range (0.07-0.12) specified herein, and the ratio of core particles satisfies the range (0.11-0.13) specified herein. The ratio of core-shell particles satisfies the range (greater than 0.13 and less than or equal to 0.16) specified herein.

[0265] The calculated crosslinking rate also showed an increasing trend, in the order of growth particles (4.82%), core particles (8.30%), and core-shell particles (12.25%). The crosslinking rate of growth particles falls within the range presented herein (4.0% or more and less than 8.0%), while the crosslinking rate of core particles falls within the range presented herein (7.0% or more and less than 9.0%). Although the crosslinking rate of core-shell particles did not satisfy the range presented herein (12.5% ​​or more and 16.0% or less), it showed an increased value compared to core particles. (Failed to satisfy the lower limit of the range presented herein, 12.5%).

[0266] The FWHM of the amorphous peak decreased from the growth particle (6.2°) to the core particle (5.9°) and then increased again at the core-shell particle (6.3°). The FWHM of the growth particle satisfies the range (6.5° or less) presented herein, and the FWHM of the core particle satisfies the range (less than 6.1°) presented herein. The FWHM of the core-shell particle is 6.3°, satisfying the range (less than 6.6°) and the range (6.6° or less) presented herein. This clearly demonstrates the feature of the present invention in which structural regularity increases during the core reinforcement stage and amorphousness increases again during the shell formation stage. The particles at all stages show a narrower FWHM than the competitor Nalco particle (6.7°), suggesting that they have a denser structure.

[0268] Experimental Example 3: Nuclear Magnetic Resonance (NMR) Analysis Results

[0269] (1) Measurement method

[0270] Using the particle suspensions of Reference Example 1, Reference Example 2, and Example 1 1 H-NMR and 29 Si-NMR analysis was performed. A Bruker 500 MHz model NMR instrument was used, and solid-state NMR spectra were obtained under Magic Angle Spinning (MAS) conditions. 1 In the H-NMR spectrum, the peak intensity in the 1.0-1.2 ppm, 1.7-1.9 ppm, and 3.4-3.6 ppm regions was analyzed to calculate the amount of effective hydroxyl groups (OH) on the particle surface. 29 In the Si-NMR spectrum, the amount of Si-O-Si bonds per unit volume was calculated by analyzing the areas of the Q3 (≈ -100 ppm) and Q4 (≈ -109 ppm) peaks.

[0272] (2) Measurement results

[0273] The results of the NMR analysis are summarized in Figures 6a-6c, Figures 7a-7c and Table 3 below.

[0275] Particle separation OH peak position (ppm) Amount of effective OH on particle surface Si-O-Si amount ( / nm) 3 ) Growth particles (Reference Example 1) 1.08, 1.80, 3.52 7.25E+06 1.86E+03 Core particles (Reference Example 2) 1.08, 1.81, 3.56 9.61E+05 6.55E+04 Core-Shell (Example 1) 1.08, 1.81, 3.55 1.08E+06 3.49E+04

[0277] 1 H-NMR analysis results showed peaks attributed to silanol (Si-OH) groups in the ranges of 1.0–1.2 ppm, 1.7–1.9 ppm, and 3.4–3.6 ppm in all samples, satisfying the range configuration presented herein. The calculated effective OH content on the particle surface decreased significantly from the grown particles (7.25E+06) to the core particles (9.61E+05), then increased slightly in the core-shell particles (1.08E+06). The effective OH content of the grown particles fell within the range presented herein (5.5 x 10⁻⁶). 6 - 8.0 x 10 6 Satisfies ), and the effective OH amount of the core particle is within the range presented herein (8.5 x 10⁻⁶ 5 - 1.0 x 10 6...satisfies ). The effective OH amount of the core-shell particle is within the range presented herein (1.05 x 10⁻⁶). 6 - 1.2 x 10 6 It satisfies ). In addition, the effective OH content of the core-shell particles is approximately 1.12 times that of the core particles, satisfying the range (1.05 to 1.5 times) presented herein. This clearly demonstrates the process in which hydroxyl groups are removed during the core reinforcement stage and new hydroxyl groups are introduced to the surface during the shell formation stage.

[0278] 29 Si-NMR analysis results, per unit volume (nm 3 The amount of Si-O-Si bonding per ) increased significantly from the grown particle (1.86E+03) to the core particle (6.55E+04), and decreased again in the core-shell particle (3.49E+04). The amount of Si-O-Si bonding in the core particle is within the range presented herein (6.0 x 10⁻⁶). 4 ~ 7.0 x 10 4 Satisfies ), and the amount of Si-O-Si bonding in the core-shell particles is within the range presented herein (3.0 x 10⁻⁶). 4 - 4.0 x 10 4 It satisfies ). The amount of Si-O-Si bonding in the core particles is approximately 1.88 times that of the core-shell particles, satisfying the range (1.2 times - 3.0 times) presented herein. This quantitatively demonstrates that the density of the silica network increases significantly through the core reinforcement step, and a relatively less dense shell is formed.

[0280] Experimental Example 4: Small-angle X-ray Scattering (SAXS / WAXS) Analysis Results

[0281] (1) Measurement method

[0282] Small-angle and wide-angle X-ray scattering (SAXS / WAXS) analysis was performed on the particle suspensions of Comparative Example (single particle shape estimation, Sample A) and Example 1 (core-shell, Sample B). 16.0 keV X-rays were used at the 4C SAXS beamline of the Pohang Accelerator Laboratory, and scattering patterns were obtained using a 2D detector (Rayonix MX225 HS). The obtained 2D patterns (Figs. 8a, 8b) were azimuthal averaged to obtain 1D scattering intensity (Absolute Intensity) curves (Fig. 9) as a function of the scattering vector (q). The core diameter, shell thickness, and total particle size were calculated through SAXS model fitting (e.g., Core-Shell Sphere model).

[0284] (2) Measurement results

[0285] The results of the SAXS analysis are shown in Figures 8a, 8b, Figure 9, and Table 4 below.

[0287] Sample form Core diameter (nm) Shell thickness (nm) Average diameter (nm) A Single particle (estimated) - - 70.48 B Core-Shell 55 15 68.97

[0289] In the case of Example 1 (Sample B), the core average diameter calculated through SAXS model fitting was analyzed to be approximately 55 nm, the shell average thickness to be approximately 15 nm, and the overall average diameter to be approximately 69 nm (not 55+15*2, model fitting result). The core diameter satisfies the range (50-60 nm) presented herein, the shell thickness satisfies the range (12-18 nm) presented herein, and the overall average diameter satisfies the range (65-75 nm) presented herein. The shell / core thickness ratio is approximately 15 / 55 ≈ 0.27, which satisfies the range (0.15-0.5) presented herein.

[0290] Looking at the 1D scattering curve (Fig. 9), in the low-angle region (Section 1, q ≈ 2.5-9.0 nm -1In the high-angle region (Section 2, q ≈ 12-17 nm), the scattering intensity of the core-shell particle (B) appears lower than that of the single particle (A) and has a gentler slope. This can be interpreted as being due to the reduction in the overall electron density contrast between the particle and the solvent caused by the difference in electron density between the core and the shell and the presence of the shell, which is consistent with the characteristic (intensity reduction) presented herein. -1 In ), the core-shell particle (B) shows a peak shape different from the single particle (A), particularly at about 14-16 nm -1 A relatively distinct peak is observed in the vicinity, satisfying the features of the present invention. This appears to reflect a change in the internal structure resulting from the formation of a core-shell structure.

[0292] Experimental Example 5: Scanning Electron Microscope (SEM) Analysis Results

[0293] (1) Measurement method

[0294] A small amount of the core-shell silica nanoparticle suspension from Example 1 was dropped onto a silicon wafer substrate and air-dried, after which the morphology and size of the particles were observed using a scanning electron microscope (SEM, model: Hitachi S-4800). Images were obtained under an acceleration voltage of 15.0 kV, and randomly selected using image analysis software 50 The diameters of more than one particle were measured, and the average value was calculated.

[0296] (2) Measurement results

[0297] The results of the SEM analysis are shown in Figures 11a to 11d. Figure 11a is a low-magnification image showing that the particles have a relatively uniform spherical shape. The average diameter of the particles measured in high-magnification images (Figures 11b-11d) was observed to be in the range of approximately 50-60 nm. This satisfies the range (45-70 nm) presented herein. This value is approximately 8-18 nm smaller than the average diameter measured by DLS (Experimental Example 1, 67.74 nm), satisfying the range (5-20 nm smaller) presented herein. This difference in size can be interpreted as having occurred due to the shrinkage of shell regions with relatively low density and irregular structure during the drying process for SEM measurement. In other words, the particle size observed on the SEM may show a tendency to be mainly proportional to the size of the reinforced core.

[0299] Experimental Example 6: Chemical Mechanical Polishing (CMP) Performance Evaluation Results

[0300] CMP slurries were prepared using the particles of Reference Example 1, Reference Example 2, Example 1, and Comparative Example 3, respectively, and the removal rate (RR) was measured on a wafer with a silicon oxide film deposited thereon. When the removal rate of Comparative Example 3 (Nalco) was set as 100%, the growth particle (Reference Example 1) showed a relative removal rate of 133%, the core particle (Reference Example 2) showed 119%, and the core-shell particle (Example 1) showed 137%. The core-shell particle (Example 1) exhibited the highest removal rate, which can be interpreted as being due to the synergistic effect between the mechanical strength of the reinforced core and the chemically active shell. The lower removal rate of the core particle compared to the growth particle may be due to a decrease in chemical polishing ability caused by the reduction of surface hydroxyl groups during the core reinforcement process. The core-shell particle of the present invention demonstrated superior polishing performance compared to competitor particles.

[0302] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0303] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention.

Claims

Claim 1 It comprises a core having a first Si-O-Si bonding structure; and a shell formed on the surface of the core and having a second Si-O-Si bonding structure, and 1 Core-shell silica nanoparticles characterized by peaks attributed to silanol (Si-OH) groups on the silica surface being observed in the ranges of 1.0 ppm to 1.2 ppm, 1.7 ppm to 1.9 ppm, and 3.4 ppm to 3.6 ppm, respectively, upon H-NMR analysis. Claim 2 Core-shell silica nanoparticles according to claim 1, characterized in that the core is obtained by reinforcing wet-grown growth particles. Claim 3 In paragraph 2, the above core is, 29 The amount of Si-O-Si bonds per unit volume in Si-NMR analysis is nm 3 6.0 x 10 per 4 Up to 7.0 x 10 4 Core-shell silica nanoparticles characterized by being. Claim 4 In claim 1, the core-shell silica nanoparticles are, 29 The amount of Si-O-Si bonds per unit volume in Si-NMR analysis is nm 3 3.0 x 10 per 4 Up to 4.0 x 10 4 Core-shell silica nanoparticles characterized by being. Claim 5 A core-shell silica nanoparticle according to claim 2, characterized in that the amount of Si-O-Si bonds per unit volume of the core is 1.2 to 3.0 times the amount of Si-O-Si bonds per unit volume of the core-shell silica nanoparticle. Claim 6 In paragraph 2, the growth particles are, 1 When analyzed by H-NMR, the amount of effective hydroxyl groups (effective OH) on the particle surface is 5.5 x 10⁶ per gram. 6 Up to 8.0 x 10 6 Core-shell silica nanoparticles characterized by being. Claim 7 In paragraph 2, the above core is, 1 When analyzed by H-NMR, the amount of effective hydroxyl groups (effective OH) on the particle surface is 8.5 x 10⁶ per gram. 5 Up to 1.0 x 10 6 Core-shell silica nanoparticles characterized by being. Claim 8 In paragraph 2, the core-shell silica nanoparticles are, 1 When analyzed by H-NMR, the amount of effective hydroxyl groups (effective OH) on the particle surface is 1.05 x 10⁶ per gram. 6 Up to 1.2 x 10 6 Core-shell silica nanoparticles characterized by being. Claim 9 A core-shell silica nanoparticle according to claim 2, characterized in that the amount of effective hydroxyl groups (effective OH) on the particle surface of the core-shell silica nanoparticle is 1.05 to 1.5 times the amount of effective hydroxyl groups (effective OH) on the particle surface of the core. Claim 10 The core-shell silica nanoparticles according to claim 1, characterized in that the core-shell silica nanoparticles have a polydispersity index (PDI) of 0.08 or higher and 0.15 or lower as measured by dynamic light scattering (DLS). Claim 11 Core-shell silica nanoparticles according to claim 1, characterized by having an average diameter of 45 nm to 70 nm as measured by a scanning electron microscope (SEM). Claim 12 The core-shell silica nanoparticles according to claim 1, characterized in that the core-shell silica nanoparticles have a shell / core thickness ratio of 0.15 or more and 0.5 or less. Claim 13 A chemical mechanical polishing composition comprising the particles of claim 1; and a solvent. Claim 14 A method for manufacturing a semiconductor device comprising the step of polishing a metal or semiconductor film using the chemical mechanical polishing composition of claim 13.

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