Non-spherical primary silica nanoparticles and their use

Abstract

A method for synthesizing non-spherical primary silica nanoparticles includes reacting at least two organoalkoxysilanes with water under alkaline conditions in a reaction mixture comprising a water-miscible organic solvent and an alkaline catalyst. The at least two organoalkoxysilanes have different reaction rates with water under alkaline conditions. Each organoalkoxysilane is a SiR 1 R 2 R 3 R 4 (I) [Case 1] JPEG2024517121000007.jpg24149In formula, R 1 , R 2 , R 3 , and R 4 are each independently selected from the group consisting of OR or R, where R is a substituted or unsubstituted straight or branched chain C1-C 12 an alkyl group, a C3-C8 alicyclic group, a C2-C6 alkylene group, a halogen, or an aryl group; R 1 , R 2 , R 3 , and R 4 At least two, preferably at least three, of the at least two organoalkoxysilanes are OR, and at least one of the at least two organoalkoxysilanes has at least three OR. The molar ratio of water (HO) to the hydrolyzable groups (OR) on the at least two organoalkoxysilanes is greater than 0 and less than 3.0, or less than 2.0.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the interests of U.S. Provisional Patent Application No. 63 / 264,912, filed on 3 December 2021, and U.S. Provisional Patent Application No. 63 / 177,539, filed on 21 April 2021, which are incorporated herein by reference as if they were fully described. [Background technology]

[0002] This disclosure relates to the production of non-spherical primary silica nanoparticles for use as abrasives in CMP compositions.

[0003] In the semiconductor industry, chemical mechanical polishing (CMP) is a well-known technique applied to the manufacture of advanced photonic, micro-electromechanical, and micro-electronic materials and devices, such as semiconductor wafers.

[0004] During the manufacturing of materials and devices used in the semiconductor industry, CMP (Chemical Polishing) is used to planarize metal and / or oxide surfaces. CMP utilizes the interaction of chemical and mechanical actions to achieve flatness of the surface to be polished. The chemical action is provided by a chemical composition, also called a CMP composition or CMP slurry. The mechanical action is typically performed by a polishing pad, which is usually pressed against the surface to be polished and mounted on a moving platen. The motion of the platen is typically linear, rotational, or orbital.

[0005] In a typical CMP method step, a rotating wafer holder brings the wafer to be polished into contact with a polishing pad. The CMP composition is typically applied between the wafer to be polished and the polishing pad.

[0006] The shape of CMP abrasives has a substantial impact on their performance in planarization methods. Recently, since it has been found that non-spherical particles can exhibit higher removal rates and higher efficiency than spherical particles, research has focused on providing a method for manufacturing non-spherical particles in a reproducible manner.

[0007] However, the reproducible synthesis of non-spherical particles is much more complex than the synthesis of spherical particles known in the art. Size control is typically the only characteristic that is monitored and adjusted during the synthesis of spherical particles, but manufacturing elongated branched particles requires controlling the size of the branches in addition to the overall three-dimensional structure. Thus, it is not surprising that the industry is seeking a cost-effective method for controlling the shape and branching of elongated nanoparticle structures.

[0008] Typically, these particles are produced today by controlled aggregation methods, in which colloidal particle formation in at least one stage of production is deliberately advanced into an unstable region such that the intermediate spherical nanoparticles begin to aggregate. The particles are then returned to a stable region when the desired size and structure have been formed. An example of the method can be found in U.S. Patent No. 8,529,787 to Fuso Chemical Co., Ltd.

[0009] However, such methods have a major drawback of being non-self-regulating. Thus, continuously monitoring and operating the reaction under such highly unstable conditions is a long and drawn-out effort. Furthermore, such prior art methods can hardly produce variations in various different shapes and degrees of branching.

[0010] [[ID=IC=16]]Therefore, there is a need in the art for a method of manufacturing elongated branched CMP abrasives such as silicon oxide that can synthesize nanoparticles of various shapes and sizes in a simple and reproducible manner. SUMMARY OF THE INVENTION

[0011] The present invention provides non-spherical primary silica nanoparticles, and satisfies this need by using the non-spherical primary silica nanoparticles as an abrasive in the CMP method.

[0012] In one aspect, it is a method for synthesizing non-spherical primary silica nanoparticles or a non-spherical primary silica nanoparticle dispersion, comprising: a) providing a first mixture containing at least two organoalkoxysilanes, each having a structure of formula I, where:

Chemical formula

[0013] The pH of the reaction mixture is generally in the range of 7 to 14, preferably 10 to 14, and more preferably 12 to 14.

[0014] Step d) can be carried out by (1) adding a water-miscible organic solvent to a mixture of at least two organoalkoxysilanes to obtain a first mixture, and adding an alkaline catalyst to the first mixture; (2) adding an alkaline catalyst to a water-miscible organic solvent to obtain a first mixture, and adding a mixture of at least two organoalkoxysilanes to the first mixture; or (3) adding a water-miscible organic solvent to a mixture of at least two organoalkoxysilanes to obtain a first mixture, adding a water-miscible organic solvent to an alkaline catalyst to obtain a second mixture, and mixing the first and second mixtures in a mixer in a flow reactor. If there is not enough water in the mixtures a) to c), water can be added to the reaction mixture.

[0015] Examples of at least two organoloxysilanes include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraoctoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, octyltrimethoxysilane, octyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyl Examples of organoloxysilanes include, but are not limited to, triethoxysilane, triethylmethoxysilane, fluorotriisopropoxysilane, fluorotrimethoxysilane, fluorotriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, trimethylbutoxysilane, trifluoromethyltrimethoxysilane, and trifluoromethyltriethoxysilane. At least two preferred organoloxysilanes include tetramethoxysilane (TMOS) and tetraethoxysilane (TEOS).

[0016] In one embodiment, where two organolalkoxysilanes are present, the first organolalkoxysilane may be present in an amount of about 50 to about 99 mol%, and the second organolalkoxysilane may be present in an amount of about 50 to about 1 mol%. In another embodiment, the first organolalkoxysilane may be present in an amount of about 75 to about 95 mol%, and the second organolalkoxysilane may be present in an amount of about 5 to about 25 mol%. In yet another embodiment, the first organolalkoxysilane may be present in an amount of about 85 to about 90 mol%, and the second organolalkoxysilane may be present in an amount of about 15 to about 10 mol%. The mol% is based on the total moles of the two organolalkoxysilanes, which constitute 100%.

[0017] The first mixture, the second mixture, and the reaction mixture may be heated and maintained at temperatures of 30°C to 70°C, 40°C to 60°C, or 48°C to 52°C.

[0018] Non-spherical primary silica nanoparticles are produced in this method with a yield of at least 50%, 75%, or 85%, based on the total weight of the particles produced.

[0019] Non-spherical primary silica nanoparticles are produced in weight% yields of 3.0 wt%–8.0 wt%, 4.0 wt%–7.0 wt%, 4.5 wt%–6.5 wt%, and 5.5 wt%–6.5 wt%. The weight% yield is based on the total weight of silica nanoparticles that can be produced by the total weight of the reaction mixture.

[0020] Non-spherical primary silica nanoparticles have shapes selected from the group consisting of elongated shapes, curved shapes, branched shapes, and combinations thereof, and have nitrogen levels (or nitrogen content) of <0.2, 0.1, 0.02, 0.01, 0.006, 0.005, or 0.004 mmol / g SiO2.

[0021] In another embodiment, non-spherical primary silica nanoparticles or a dispersion of non-spherical primary silica nanoparticles are provided, wherein the non-spherical primary silica nanoparticles have shapes selected from the group consisting of elongated shapes, curved shapes, branched shapes, and combinations thereof, and have a nitrogen level (or nitrogen content) of <0.2, 0.1, 0.02, 0.01, 0.006, 0.005, or 0.004 mmol / g SiO2.

[0022] In yet another embodiment, a chemomechanical planarization (CMP) composition is provided comprising non-spherical primary silica nanoparticles or a dispersion of non-spherical primary silica nanoparticles, wherein the non-spherical primary silica nanoparticles have shapes selected from the group consisting of elongated, curved, branched, and combinations thereof, and have a nitrogen level (or nitrogen content) of <0.2, 0.1, 0.02, 0.01, 0.006, 0.005, or 0.004 mmol / g SiO2. [Brief explanation of the drawing]

[0023] [Figure 1]This is a scanning electron microscope (SEM) image of non-spherical primary silica nanoparticles produced by Example 2 at 20,000x magnification. [Figure 2] This is a 100,000x magnification SEM image of non-spherical primary silica nanoparticles produced by Example 2. [Figure 3] This is a 20,000x magnification SEM image of non-spherical primary silica nanoparticles produced by Example 3. [Figure 4] This is a 100,000x magnification SEM image of non-spherical primary silica nanoparticles produced by Example 3. [Figure 5] This is a 20,000x magnification SEM image of non-spherical primary silica nanoparticles produced by Example 4. [Figure 6] This is a 100,000x magnification SEM image of non-spherical primary silica nanoparticles produced by Example 4. [Modes for carrying out the invention]

[0024] All references cited herein, including publications, patent applications, and patents, are incorporated herein by reference to the same extent as they are incorporated herein in whole, with each reference being individually and specifically indicated as being incorporated herein by reference.

[0025] In the context describing this invention (particularly in the context of the claims below), the terms “a,” “an,” and “the,” and similar references, should be interpreted as covering both singular and plural forms unless otherwise indicated herein or explicitly refuted by the context. The terms “comprising,” “having,” “including,” and “containing” should be interpreted as open-ended terms (i.e., “including, but not limited to”) unless otherwise indicated herein. Enumerations of value ranges herein are merely intended to serve as abbreviations for referring individually to each individual value within that range unless otherwise indicated herein, and each individual value is incorporated herein as if it were individually enumerated herein. All methods described herein may be performed in any preferred order unless otherwise indicated herein or explicitly refuted by the context. Any and all examples or exemplary language provided herein (e.g., "etc.") are intended solely to better illustrate the invention and, unless otherwise claimed, do not limit the scope of the invention. No language in this specification should be construed as indicating any unclaimed element essential to the practice of the invention.

[0026] As used herein and in the claims, the terms “comprising,” “comprises,” “including,” and “includes” are inclusive or open-ended and do not exclude additional unlisted elements, composition components, or method steps. These terms thus encompass the more restrictive terms “consisting essentially of” and “consisting of.” Unless otherwise specified, all values ​​provided herein include the given endpoint, and the values ​​of composition components or ingredients are expressed as weight percentages of each component in the composition.

[0027] Embodiments including the best mode known to the inventors for carrying out the present invention are described herein. Variations of these embodiments may be apparent to those skilled in the art by reading the foregoing description. The inventors anticipate that those skilled in the art will use such variations as needed, and they intend that the present invention may be carried out in ways other than those specifically described herein. Accordingly, the present invention includes all variations and equivalents of the subject matter referenced in the claims appended herein, as permitted by applicable law. Furthermore, any combination of the above elements in all possible variations thereof is encompassed by the present invention unless otherwise indicated herein or expressly rejected by the context.

[0028] The terms "nanoparticles" and "colloids" are synonymous and refer to particles with a size of 1 to 1000 nanometers.

[0029] Where used herein, "approximately" is intended to correspond to ±5% of the stated value.

[0030] In all such compositions in which a particular component of the composition is discussed with reference to a weight percentage range including a lower limit of 0, it will be understood that such component may or may not be present in various specific embodiments of the composition, and, if such component is present, it may be present at a low concentration of about 0.00001 weight percent based on the total weight of the composition in which such component is used.

[0031] The term "non-spherical silica nanoparticles" refers to both non-spherical primary silica nanoparticles and non-spherical secondary silica nanoparticles.

[0032] As used herein, the term “non-spherical” includes all shapes or structures that are not spherical. This includes, but is not limited to, “elongated,” “curved,” and “branched,” as well as any combination thereof.

[0033] The term "non-spherical primary silica nanoparticles" refers to primary silica particles that have a structure in which silica grows in a non-linear, elongated, curved, branched, or combined shape. More specifically, it refers to a structure in which silica particles grow non-uniformly in multiple directions simultaneously, thereby generating a non-spherical structure.

[0034] In contrast to non-spherical primary silica nanoparticles, spherical primary silica nanoparticles refer to a structure in which silica particles grow uniformly in all directions, thereby generating a spherical structure.

[0035] The term "non-spherical primary silica nanoparticles" does not include aggregated particles, aggregated primary particles, or aggregated spherical primary particles.

[0036] The present invention provides a method for synthesizing non-spherical primary silica nanoparticles using at least two organoalkoxysilanes simultaneously, wherein the selected organoalkoxysilanes have different reaction rates with water under alkaline conditions.

[0037] Specifically, the present invention relates to a method for synthesizing non-spherical primary silica nanoparticles or a dispersion of non-spherical primary silica nanoparticles, the method comprising the following steps: a) A step of providing a first mixture of at least two organoalkoxysilanes, wherein each organoalkoxysilane independently has a structure represented by formula I, [ka] During the ceremony, R 1 , R 2 , R 3 , and R 4 Each is independently selected from the group consisting of OR or R, where R is a substituted or unsubstituted linear or branched chain of C1-C1. 12 R is an alkyl group, a C3-C8 alicyclic group, a C2-C6 alkylene group, a halogen, or an aryl group. 1 , R 2 , R 3, and R 4 At least two of these, preferably at least three, are OR. At least one of at least two organoalkoxysilanes is R 1 , R 2 , R 3 , and R 4 It has at least three of these, preferably all of them, as OR. And at least two organoalkoxysilanes have different reaction rates with water under alkaline conditions, step, b) A step of providing a water-miscible organic solvent, c) A step of providing an alkaline catalyst, d) A step of obtaining a reaction mixture comprising a) to c), wherein the reaction mixture contains water, and the molar ratio (ROR) of water (H2O) to hydrolyzable groups (OR) on at least two organoalkoxysilanes is greater than 0 and less than 3.0, or less than 2.0, for example, 0.5 to 1.5 according to the formula: ROR = M(H2O) / M(OR), e) A step of forming non-spherical primary silica nanoparticles by reacting at least two organoalkoxysilanes with water in a reaction mixture under alkaline conditions, and Optionally, f) After non-spherical primary silica nanoparticles are formed, replace at least a portion of the water-miscible organic solvent with water to obtain a dispersion of non-spherical primary silica nanoparticles; The present invention provides a method comprising the step of adding water in step d) if there is not enough water from a) to c) to satisfy the ROR in step d).

[0038] The pH of the reaction mixture is generally in the range of 7 to 14, preferably 10 to 14, and more preferably 12 to 14.

[0039] Step d) can be carried out by (1) adding a water-miscible organic solvent to a mixture of at least two organoalkoxysilanes to obtain a first mixture, and adding an alkaline catalyst to the first mixture; (2) adding an alkaline catalyst to a water-miscible organic solvent to obtain a first mixture, and adding a mixture of at least two organoalkoxysilanes to the first mixture; or (3) adding a water-miscible organic solvent to a mixture of at least two organoalkoxysilanes to obtain a first mixture, adding a water-miscible organic solvent to an alkaline catalyst to obtain a second mixture, and mixing the first and second mixtures in a mixer in a flow reactor. If there is not enough water in the mixtures a) to c), water can be added to the reaction mixture.

[0040] Examples of at least two organoloxysilanes include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraoctoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, octyltrimethoxysilane, octyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyl Examples of organoloxysilanes include, but are not limited to, tetramethoxysilane, triethylmethoxysilane, fluorotriisopropoxysilane, fluorotrimethoxysilane, fluorotriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, trimethylbutoxysilane, trifluoromethyltrimethoxysilane, and trifluoromethyltriethoxysilane. Preferred organoloxysilanes include at least two organoloxysilanes, tetramethoxysilane and tetraethoxysilane.

[0041] Preferred organoalkoxysilanes include at least two organoalkoxysilanes and tetraethoxysilanes.

[0042] The concentrations (mol%) of at least two organoalkoxysilanes can be any value.

[0043] In one embodiment, where two organoalkoxysilanes are present, the first organoalkoxysilane may be present in an amount of about 50 to about 99 mol%, and the second organoalkoxysilane may be present in an amount of about 50 to about 1 mol%. In another embodiment, the first organoalkoxysilane may be present in an amount of about 75 to about 95 mol%, and the second organoalkoxysilane may be present in an amount of about 5 to about 25 mol%. In yet another embodiment, the first organoalkoxysilane may be present in an amount of about 85 to about 90 mol%, and the second organoalkoxysilane may be present in an amount of about 15 to about 10 mol%. The mol% is based on the total moles of the two organoalkoxysilanes, which constitute 100%.

[0044] The first mixture, the second mixture, and the reaction mixture may be heated and maintained at temperatures of 30°C to 70°C, 40°C to 60°C, or 48°C to 52°C.

[0045] Non-spherical primary silica nanoparticles are produced in this method with a yield of at least 50%, 75%, or 85% based on the total weight of the particles produced. That is, 50%, 75%, or 85% of the total particles produced in the method are non-spherical primary silica nanoparticles.

[0046] Non-spherical primary silica nanoparticles are produced in weight% yields of 3.0 wt%–8.0 wt%, 4.0 wt%–7.0 wt%, 4.5 wt%–6.5 wt%, and 5.5 wt%–6.5 wt%. The weight% yield is based on the total weight of silica nanoparticles that can be produced by the total weight of the reaction mixture.

[0047] Non-spherical primary silica nanoparticles have shapes selected from the group consisting of elongated shapes, curved shapes, branched shapes, and combinations thereof, and have nitrogen levels (or nitrogen content) of <0.2, 0.1, 0.02, 0.01, 0.006, 0.005, or 0.004 mmol / g SiO2.

[0048] Here again, the term "non-spherical primary nanoparticles" does not include aggregated particles such as aggregated primary particles.

[0049] The methods disclosed herein allow the degree of elongation, bending, and / or branching to be adjusted to a desired degree.

[0050] The components of the reaction mixture and the reaction method are described in detail herein.

[0051] Organoalkoxysilanes The Stober method is a well-known prior art method for producing spherical silica particles. In the Stober method, tetraethyl orthosilicate (TEOS) is added under stirring to a solution of excess water, alcohol, and ammonium hydroxide to form spherical nanoparticles. However, the method of the present invention involves a modification of the Stober method that yields the surprising and unexpected result of non-spherical primary silica nanoparticles.

[0052] In other words, the method of the present invention comprises the step of reacting at least two organoalkoxysilanes with water in a reaction mixture.

[0053] Each of at least two organoalkoxysilanes independently has a structure represented by the following formula I: [ka] R 1 , R 2 , R 3 , and R 4 Each is independently selected from the group consisting of OR or R, where R is a substituted or unsubstituted linear or branched chain of C1-C1. 12R is an alkyl group, a C3-C8 alicyclic group, a C2-C6 alkylene group, a halogen, or an aryl group. 1 , R 2 , R 3 , and R 4 At least two, preferably at least three of these, are OR.

[0054] At least one of at least two organoalkoxysilanes is R 1 , R 2 , R 3 , and R 4 It has at least three of these, preferably all of them, as OR.

[0055] Examples of organoalkoxysilanes represented by formula I include tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), tetraisopropoxysilane, tetrabutoxysilane, tetraoctoxysilane, methyltrimethoxysilane (MTMS), methyltriethoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, octyltrimethoxysilane, octyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane Examples include lan, phenyltrimethoxysilane, phenyltriethoxysilane, triethylmethoxysilane, fluorotriisopropoxysilane, fluorotrimethoxysilane, fluorotriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, trimethylbutoxysilane, trifluoromethyltrimethoxysilane, and trifluoromethyltriethoxysilane.

[0056] At least two organoalkoxysilanes should be intentionally selected so that they react with water at different rates under alkaline conditions. Therefore, SiO2 seed formation by each organoalkoxysilane will begin at different times.

[0057] While not bound by any particular theory, taking the two organoalkoxysilanes in the reaction of the present invention as an example, the organoalkoxysilane with a faster reaction rate first reacts with water to form a silanol, and then, according to the well-established LaMer theory, forms SiO2 seeds. While these seeds begin to grow, the other organoalkoxysilane with a slower reaction rate begins to produce new silanols, which in turn produce new seeds. Thus, seed formation and particle growth reactions occur simultaneously due to the different reaction rates of the two organoalkoxysilanes with water. The new seeds can grow on their own, or they can adhere to the growing seeds to form another seed. Due to the interference of the reactions of the two organoalkoxysilanes, seed formation and growth are no longer separate, thus resulting in the non-uniform growth of particles in all dimensions. As a result, the method of the present invention produces the surprising and unexpected result of non-spherical primary silica nanoparticles.

[0058] This method is unique compared to known methods that use only one organoalkoxysilane or use them simultaneously, because it uses at least two organoalkoxysilanes with different reaction rates with water under alkaline conditions.

[0059] In one embodiment, where two organoalkoxysilanes are present, the first organoalkoxysilane may be present in an amount of about 50 to about 99 mol%, and the second organoalkoxysilane may be present in an amount of about 50 to about 1 mol%. In another embodiment, the first organoalkoxysilane may be present in an amount of about 75 to about 95 mol%, and the second organoalkoxysilane may be present in an amount of about 5 to about 25 mol%. In yet another embodiment, the first organoalkoxysilane may be present in an amount of about 85 to about 90 mol%, and the second organoalkoxysilane may be present in an amount of about 15 to about 10 mol%. The mol% is based on the total moles of the two organoalkoxysilanes, which constitute 100%.

[0060] In some embodiments, at least two organoalkoxysilanes are TEOS and TMOS. In embodiments, TEOS is present in about 75 to about 98 mol%, TMOS in about 2 to about 25 mol%, more preferably TEOS in about 85 to about 95 mol%, TMOS in about 5 to about 15 mol%, and most preferably TEOS in about 88 to about 92.5 mol%, TMOS in about 7.5 to about 12 mol%. For example, in one embodiment, TEOS is present in 90 mol%, and TMOS in 10 mol%.

[0061] water Water is a reactant in the method of the present invention. In contrast to what is known in the art with respect to the Stober method, the inventors have found that the effect on the shape of silica nanoparticles can be influenced not only by the different reaction rates of at least two organoalkoxysilanes, but also by the amount of water present in the reaction mixture. The literature typically teaches the use of excess water in the Stober method, but excess water used with a mixture of at least two organoalkoxysilanes results in only a slight deviation from spherical shape. The inventors have found that when less water is used for the hydrolysis reaction in the current method, a more significant deviation is observed. Preferably, the water content is present in a molar ratio ROR of less than 3 or less than 2, where ROR is defined as the molar ratio of water to the hydrolyzable group of the organoalkoxysilane, and ROR = M(H2O) / M(OR). Most preferably, ROR is 0.5 (stoichiometric minimum for complete hydrolysis and condensation) to 1.0.

[0062] It is preferable to use water from the catalyst solution, for example, a 25-35% aqueous ammonia solution, as the sole water source.

[0063] If the catalyst solution used in the method does not contain water, or does not contain enough water, water can be added to the reaction mixture.

[0064] Water-miscible organic solvent A water-miscible organic solvent is used in the method of the present invention.

[0065] Examples of organic solvents include alcohols, ketones, ethers, glycols, and esters, with alcohols being preferred. More specifically, alcohols such as methanol, ethanol, propanol, and butanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; glycol ethers such as propylene glycol monopropyl ether; glycols such as ethylene glycol, propylene glycol, and hexylene glycol; and esters such as methyl acetate, ethyl acetate, methyl lactate, and ethyl lactate are preferred. Among these, methanol or ethanol is more preferred, and ethanol is particularly preferred. These water-miscible organic solvents may be used individually or as a mixture of two or more.

[0066] A water-miscible organic solvent is preferably used in the reaction mixture in an amount of about 25% to about 95% by weight of the total weight of the reaction mixture. In other embodiments, the water-miscible organic solvent is used in an amount of 40% to about 90% by weight, or about 50% to about 80% by weight, of the reaction mixture.

[0067] Alkaline catalyst At least one type of alkaline catalyst is used in the method of the present invention.

[0068] The alkaline catalyst is selected from the group consisting of ammonia (NH3), ammonium hydroxide, organic amines, alkanolamines, quaternary ammonium hydroxide compounds, and combinations thereof.

[0069] Preferred alkali catalysts include ammonia (NH3) or at least one organic amine.

[0070] Examples of organic amines suitable for use as at least one alkali catalyst include hexylamine, 5-amino-2-methylpentane, heptylamine, octylamine, nonylamine, decylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, di-n-butylamine, di-t-butylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, amylmethylamine, methylisoamylamine, tripropylamine, and tributylamine. N-, tripentylamine, dimethylethylamine, methyldiethylamine, methyldipropylamine, N-ethylidenemethylamine, N-ethylideneethylamine, N-ethylidenepropylamine, N-butylamineethylidene, alkanolamine, ethanolamine, N-methylethanolamine, N-ethylethanolamine, N-propylethanolamine, N-butylethanolamine, diethanolamine, 1-amino-2-propanol, N-methylamine isopropanol, N-ethylisopropanolamine, N-propyl Luisopropanolamine, 2-aminopropan-1-ol, N-methyl-2-aminopropan-1-ol, N-ethyl-2-aminopropan-1-ol, 1-aminopropan-3-ol, N-methyl-1-aminopropan-3-ol, N-ethyl-1-aminopropan-3-ol, 1-aminobutan-2-ol, N-methyl-1-aminobutan-2-ol, N-ethyl-1-aminobutan-2-ol, 2-aminobutan-1-ol, N-methyl-2-aminobutan-1-ol, N-ethyl-2-aminobutan-1- All, N-hydroxymethylethanolamine, N-hydroxymethylethylenediamine, N,N'-bis(hydroxymethyl)ethylenediamine, N-hydroxymethylpropanolamine, ethylenediamine, propylenediamine, trimethylenediamine, tetramethylenediamine, 1,3-diaminobutane, 2,3-diaminobutane, pentamethylenediamine, 2,4-diaminopentane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, N-methylethylenediamine, N,Examples include N-dimethylethylenediamine, trimethylethylenediamine, N-ethylethylenediamine, N,N-diethylethylenediamine, triethylethylenediamine, 1,2,3-triaminopropane, hydrazine, tris(2-aminoethyl)amine, tetra(aminomethyl)methane, diethylenetriamine, triethylenetetramine, tetraethylpentamine, heptaethyleneoctamine, nonaethylenedecamine, diazabicycloundecene, hydroxylamine, N-methylhydroxylamine, N-ethylhydroxylamine, N,N-diethylhydroxylamine, oligos and polyethyleneimines, and mixtures thereof.

[0071] Suitable examples of alkanolamines include primary, secondary, and tertiary alkanolamines having 1 to 5 carbon atoms, such as N-methylethanolamine (NMEA), monoethanolamine (MEA), N-methyldiethanolamine, diethanolamine, mono, di, and triisopropanolamines, 2-(2-aminoethylamino)ethanol, 2-(2-aminoethoxy)ethanol, triethanolamine, and mixtures thereof. In one embodiment, the alkanolamine is selected from the group consisting of triethanolamine (TEA), diethanolamine, N-methyldiethanolamine, diisopropanolamine, N-methylethanolamine, and mixtures thereof.

[0072] Examples of quaternary ammonium hydroxide compounds suitable for use as at least one alkali catalyst include tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrabutylammonium hydroxide (TBAH), tetrapropylammonium hydroxide, trimethylethylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide, (2-hydroxyethyl)triethylammonium hydroxide, (2-hydroxyethyl)tripropylammonium hydroxide, (1-hydroxypropyl)trimethylammonium hydroxide, ethyltrimethylammonium hydroxide, diethyldimethylammonium hydroxide, and benzyltrimethylammonium hydroxide, or mixtures thereof.

[0073] The amount of alkaline catalyst added to the reaction mixture may be adjusted as appropriate so that the pH of the reaction mixture is maintained within the range of 7 to 14, preferably 10 to 14, and more preferably 12 to 14.

[0074] The alkaline catalyst can be added to a mixture of at least two organoalkoxysilanes and a water-miscible organic solvent, or it can be added first to a water-miscible organic solvent and then to a mixture of at least two organoalkoxysilanes to obtain a reaction mixture.

[0075] In a preferred embodiment, the alkaline catalyst is added with stirring to a mixture of at least two organoalkoxysilanes and a water-miscible organic solvent to obtain a reaction mixture. The catalyst can exist as an aqueous solution, such as a 25% to 35% aqueous solution of ammonia, and as a result, water as a reactant is added simultaneously with the catalyst.

[0076] The catalyst may be added slowly or in a single step. Preferably, the catalyst is added rapidly to a preheated silane / solvent mixture while vigorously stirring.

[0077] A typical reaction time is 1 to 5 hours. Preferably, both the silane / solvent mixture and the catalyst are heated. More preferably, both are heated to the same temperature before mixing. Exemplary temperatures include those in the ranges of 30°C to 70°C, 40°C to 60°C, and 48°C to 52°C.

[0078] This method should be designed to avoid evaporation of volatile catalysts (e.g., NH3) from the reaction mixture. To ensure that the reaction proceeds to the desired extent (particle formation), a continuous pipe / flow reactor or a batch reactor with sufficiently long pipes can be used. When the reaction is carried out in the presence of a nitrogen-containing alkaline catalyst, nitrogen compounds can be trapped inside the colloidal silica abrasive particles during particle growth, thus resulting in colloidal silica abrasive particles containing nitrogen-containing compounds internally incorporated within the particles. The nitrogen content in the particles can be measured using nitrogen levels or nitrogen content (millimoles / gram silica or mmol / g silica).

[0079] Since the method of the present invention is carried out with less water compared to the typical Stober method, in some embodiments, after the reaction is complete or nearly complete, excess water can be added with stirring for 1 to 60 minutes to ensure that all reaction sites on the organoalkoxysilane are used up. Preferably, excess water is added to achieve a ROR value of at least ≥1.0, most preferably ≥2.0. Due to the unique method of particle growth, colloidal silica having non-spherical, elongated, curved, and branched structures can be obtained by the method of the present invention.

[0080] Optionally, a second growth step can be performed depending on the desired properties of the colloidal silica particles. For example, in one embodiment, the method of the present invention further includes the step of adding at least one organoalkoxysilane and water, and optionally more alkaline catalysts, to the reaction mixture. Two or more organoalkoxysilanes may also be added, but the optional second growth step is preferably performed using only one organoalkoxysilane compound, such as TEOS. The addition rate of the second step is preferably such that the organoalkoxysilane is added dropwise to maintain the pH of the liquid mixture at ≥7, preferably 12-14. The addition rate of organoalkoxysilane for the optional second growth step is preferably 0.7-41 g silica / hour / kg reaction mixture.

[0081] The next step of the method of the present invention, once non-spherical primary silica nanoparticles have been formed, includes replacing at least a portion of the water-soluble organic solvent with water to obtain a dispersion of silica nanoparticles in water. Such a solvent exchange step can be carried out using any known process for exchanging the organic solvent with water, such as distillation or cross-flow filtration. The solvent exchange step is preferably carried out until as much of the organic solvent as possible has been removed, according to the inherent limitations of the process used. Preferably, the substitution step includes adding water in an amount such that the molar ratio (ROR) of water to hydrolyzable groups on the organoalkoxysilane is 2.0 or greater. If the solvent exchange is carried out by distillation, it is preferable to add a diluted ammonia solution (1-15% NH3 in water) instead of pure water for at least part of the method to ensure that the pH never drops below pH 8, which could affect colloidal stability.

[0082] In a preferred embodiment, the dispersion obtained after the solvent exchange step is concentrated by any preferred means to obtain a solid concentration of 15-25% or more.

[0083] The method of the present invention may include other optional steps such as chemically modifying the surface of the manufactured colloidal silica. There are important characteristics of the silica surface that affect the etching rate and the final surface state. A typical silica surface is terminated (covered) with -OH groups under neutral or basic conditions. The silica surface is hydrophilic and therefore "wettable." These groups activate the surface for many possible chemical or physical absorption phenomena. The Si-OH groups enable the formation of salts and protons (H + These Si-O - Furthermore, Si-OH can also act as ligands for complexing Al, Fe, Cu, Sn, and Ca. Of course, the surface is highly bipolar, and therefore, static charge can accumulate or dissipate depending on the pH, ionic concentration, and charge of the bulk solution. This accumulated surface charge can be measured as the zeta potential.

[0084] CMP liquids containing abrasive particles may require pH adjustment, for example, if a high zeta potential is achievable to maintain colloidal stability. In abrasive-containing liquids, it is undesirable for particles to settle from the suspension. The charge surrounding the interface between the particles and the liquid strongly influences the stability of the colloidal system. Zeta potential measures the potential of the particle surface at its shear surface and provides a general measure of the stability of the colloidal system. To maintain a stable colloidal system, a high zeta potential, either positive or negative, is desirable. The zeta potential of a particular particle decreases to 0 at the pH corresponding to its isoelectric point. Therefore, to enhance colloidal stability, the pH of the system should differ from the pH at its isoelectric point. For example, the isoelectric point of silica slurry is pH 2. Preferably, the silica slurry is then maintained at an alkaline pH to enhance colloidal stability. Other variables that affect the colloidal stability of a particle system include particle density, particle size, particle concentration, and chemical environment.

[0085] Therefore, any step of chemically modifying the surface of the manufactured colloidal silica may include any surface modification for adjusting the zeta potential of the colloidal dispersion or for imparting any other desired functionality to the surface of the colloidal silica. The colloidal silica particles can be surface modified using any suitable method known in the art, which includes modifying the surface of the colloidal silica by adding metal ions, boron, aluminum, etc. Any modifying step may also include treatment with a surface modifier such as silanes, including amino-containing silanes, sulfur-containing silanes, carboxyl-containing silanes, phosphorus-containing silanes, alkylsilanes, etc.

[0086] In one embodiment, the step of modifying the surface of non-spherical silica nanoparticles includes substituting at least a portion of the surface silanol groups with at least one selected from the group consisting of organosilanes, organic polymers, inorganic polymers, surfactants, and inorganic salts.

[0087] In preferred embodiments, the step of modifying the surface of non-spherical silica nanoparticles includes substituting at least a portion of the surface silanol groups with organosilanes selected from the group consisting of amino-functional alkoxysilanes, cyano-functional alkoxysilanes, alkyl and aryl-functional alkoxysilanes, sulfur silanes, and phosphate silanes. Examples of sulfur silanes include mercaptopropyltriethoxysilane, mercaptopropyltrimethoxysilane, and bis[3-(triethoxysilyl)propyl]polysulfide (registered trademark "Si 69", manufactured by Evonik). Examples of phosphate silanes include N-diphenylphosphoryl-3-aminopropyltriethoxysilane, 3-(trihydroxysilyl)propylmethylphosphonate (ammonium salt), and 2-(diethylphosphatoethyl)methyldiethoxysilane.

[0088] In some applications, the pH of the dispersion may be preferably acidic. This can be achieved, for example, by any means known to those skilled in the art, such as when the present cations are H +This can be achieved by passing a colloidal silica dispersion through an ion exchange resin or by adding a suitable acid until ion exchange occurs. Such ion exchange can be performed either before or after any surface modification step.

[0089] Various particle stabilizing additives can be added to the dispersion. These include surfactant compounds. Suitable surfactant compounds include, for example, any of the many nonionic, anionic, cationic, or amphoteric surfactants known to those skilled in the art. The surfactant compound may be present in the slurry composition at a concentration of about 0% to about 1% by weight of the total weight of the slurry, and if present, preferably at a concentration of about 0.001% to about 0.1% by weight.

[0090] Depending on the specific end use, other compounds may be added to the dispersions prepared herein. These include chelating agents, corrosion inhibitors, colloidal stabilizers, organic or inorganic salts, and biological agents such as bactericides, biocides, and fungicides.

[0091] Manufactured silica nanoparticles The silica nanoparticles produced herein mainly consist of non-spherical primary silica particles, i.e., they are elongated and / or curved and / or branched particles. Preferably, non-spherical primary silica nanoparticles constitute about 75%, 85%, or more of the silica nanoparticles produced according to the methods of the present invention disclosed herein.

[0092] From a commercial standpoint, a key aspect of methods for producing non-spherical primary nanoparticles is yield. Yield is defined as the total weight of silica nanoparticles that can be produced by the total weight of the reaction mixture, and is typically reported as a weight percent yield.

[0093] The typical Stober method has very limited yields because attempts to achieve higher yields often result in uncontrolled aggregation, precipitation, or heterogeneous size distribution. Therefore, the Stober method is typically performed with yields of 1–3%, meaning that the majority of the reaction mixture is solvent, which must be removed in expensive subsequent treatments.

[0094] The described method for producing non-spherical primary silica nanoparticles offers a unique advantage in that it can be carried out in very high yields, which are not possible with the known Stober method described in the prior art.

[0095] The described method can be carried out in yields ranging from 0.5 to 15%, preferably 3% to 8%, and most preferably 5% to 7%, which is a significant advantage as it requires only about half the amount of solvent compared to the known Stober method in the latest technology. Therefore, in subsequent processing, only half the amount of solvent needs to be replaced with water or removed.

[0096] The examples in this application showed yields of 4.5–6.5% or 5.5–6.5%.

[0097] Non-spherical primary silica particles can come into contact with each other, form certain types of bonds such as hydrogen bridges or covalent bonds, and aggregate to form secondary particles. Silica secondary particles are mostly non-spherical, or have elongated, curved, and / or branched structures.

[0098] The term "aspect ratio" refers to the ratio of the long axis to the short axis of a particle. Preferably, non-spherical primary silica nanoparticles manufactured according to the method disclosed herein have an average aspect ratio of the particles observed in the above figure (average aspect ratio) of preferably 1.5 or more, more preferably less than 5. If the average aspect ratio exceeds 5, handling becomes difficult due to increased viscosity, and gelation may occur.

[0099] Non-spherical primary silica nanoparticles can have average particle sizes of approximately 15 nm to 200 nm, approximately 20 nm to 200 nm, approximately 20 nm to 150 nm, approximately 20 nm to 120 nm, approximately 20 nm to 110 nm, approximately 20 nm to 110 nm, approximately 30 nm to 110 nm, approximately 30 nm to 100 nm, approximately 30 nm to 90 nm, approximately 30 nm to 80 nm, or approximately 40 nm to 70 nm. Alternatively, or in addition, non-spherical primary silica nanoparticles can have average particle sizes of approximately ≥10 nm, approximately ≥15 nm, and approximately ≤200 nm, approximately ≤150 nm, approximately ≤120 nm, approximately ≤100 nm, approximately ≤90 nm, approximately ≤80 nm, or approximately ≤70 nm. Thus, non-spherical primary silica nanoparticles can have average particle sizes bounded by any two of the aforementioned endpoints.

[0100] Non-spherical silica secondary nanoparticles can have any preferred average particle size. For example, non-spherical silica secondary nanoparticles can have an average particle size of about 15 nm to 600 nm, about 20 nm to 600 nm, about 25 nm to 550 nm, about 30 nm to 500 nm, about 35 nm to 450 nm, about 40 nm to 400 nm, about 45 nm to 350 nm, about 50 nm to 300 nm, or about 50 nm to 200 nm. Alternatively, or in addition, non-spherical silica secondary nanoparticles can have an average particle size of about ≥15 nm and ≤600 nm, about ≤500 nm, about ≤400 nm, about ≤300 nm, or about ≤200 nm. Thus, silica nanoparticles can have an average particle size bounded by any two of the aforementioned endpoints. Preferably, the non-spherical primary particles of the present invention do not aggregate to form secondary particles, or form only a few secondary particles.

[0101] Therefore, in another embodiment, the present invention provides non-spherical primary silica nanoparticles prepared by the method disclosed above.

[0102] Furthermore, the non-spherical primary silica nanoparticles of the present invention have a curved and / or branched structure and therefore have a large aspect ratio. The elongated / curved / aggregated primary silica particles of the present invention overlap or intertwine with each other, so they exhibit excellent coatability and can therefore improve coatability when used as a vehicle in aqueous coating compositions.

[0103] The non-spherical primary silica nanoparticles produced herein exhibit higher removal rates and higher efficiency compared to spherical particles, making them excellent abrasives for use in CMP compositions. Accordingly, in another embodiment, a CMP composition comprising non-spherical primary silica nanoparticles produced according to the method disclosed herein is provided herein.

[0104] Because the particles of the present invention have an unprecedentedly complex structure, when non-spherical primary silica nanoparticles are used as an abrasive, the contact resistance between the abrasive and the surface to be polished can be adjusted to improve the polishing speed.

[0105] The present invention will be described in further detail below with respect to examples and comparative examples. However, the present invention is not limited thereto. [Examples]

[0106] Example 1: Synthesis of elongated particles (5% TMOS 95% TEOS, ROR 0.75) 1204.96 mmol of ethanol was heated to 50°C with stirring. Ammonium hydroxide solution (32% by weight, 74.78 mmol) was added to obtain the first mixture. The mixture was further stirred until it reached 50°C again. Next, a mixture of tetraethoxysilane (TEOS) (47.5 mmol) and tetramethoxysilane (TMOS) (2.5 mmol), preheated to 50°C, was rapidly added to the first mixture in one go with vigorous stirring to obtain a reaction mixture with a ROR of 0.75. Stirring was continued for 10 seconds and then stopped. The reaction mixture was maintained at 50°C overnight.

[0107] The dispersion was stirred, and 50 mmol of deionized water was slowly added, followed by stirring at 50°C for 8 hours. The particles had an average particle size of 91.2 nm and a polydispersity index (PDI) of 0.078 as measured by dynamic light scattering (DLS).

[0108] Example 2: Synthesis of elongated particles (10% TMOS, 90% TEOS, ROR 0.75) 12346.97 mmol of ethanol was heated to 50°C under stirring. Ammonium hydroxide solution (32% by weight, 747.36 mmol) was added to obtain the first mixture. The mixture was further stirred until it reached 50°C again. Then, a mixture of tetraethoxysilane (TEOS) (451.17 mmol) and tetramethoxysilane (TMOS) (50.07 mmol), preheated to 50°C, was rapidly added to the first mixture in one go with vigorous stirring to obtain the reaction mixture. Stirring was continued for 10 seconds and then stopped. The reaction mixture was maintained at 50°C overnight. The particles had an average particle size of 66.5 nm and a PDI of 0.086 as measured by DLS.

[0109] Figures 1 and 2 are SEM micrographs showing non-spherical primary silica nanoparticles produced by Example 2.

[0110] Example 3: (TEOS:TPOS 80:20, ROR 0.75) 1234.7 mmol of ethanol was heated to 50°C with stirring. Ammonium hydroxide solution (32% by weight, 70.11 mmol) was added to obtain the first mixture. The first mixture was further stirred until it reached 50°C again. Then, a mixture of tetraethoxysilane (TEOS) (40.06 mmol) and tetrapropoxysilane (TPOS) (10.02 mmol), preheated to 50°C, was added all at once with vigorous stirring to obtain the reaction mixture. Stirring was continued for 10 seconds and then stopped. The reaction mixture was maintained at 50°C overnight. The particles had an average particle size of 50.0 nm and a PDI of 0.051 as measured by DLS.

[0111] Figures 3 and 4 are SEM micrographs showing non-spherical primary silica nanoparticles produced by Example 3.

[0112] Example 4: (60% TEOS, 40% TPOS, ROR 0.75) 1234.7 mmol of ethanol was heated to 50°C under stirring. Ammonium hydroxide solution (32% by weight, 74.78 mmol) was added to obtain the first mixture. The mixture was further stirred until it reached 50°C again. Then, a mixture of tetraethoxysilane (TEOS) (30.50 mmol) and tetrapropoxysilane (TPOS) (20.50 mmol), preheated to 50°C, was rapidly added to the first mixture in one go with vigorous stirring to obtain the reaction mixture. Stirring was continued for 10 seconds and then stopped. The reaction mixture was maintained at 50°C overnight. The particles had an average particle size of 53.5 nm and a PDI of 0.053 as measured by DLS.

[0113] Figures 5 and 6 are SEM micrographs showing non-spherical primary silica nanoparticles produced by Example 4.

[0114] Example 5: Ion exchange and pH shift to acidic pH 1247.1 g of the nanoparticle dispersion from Example 2 was stirred, and 700 g of the ion exchanger Amberlite IRN-150 was added. After stirring for 1 hour, the ion exchanger was filtered off. The pH was measured with a pH electrode and was found to be 4.3. HNO3 (1%) was slowly added until the pH of the dispersion became 2.0.

[0115] Example 6: Surface modification, zeta potential adjustment, and solvent transfer 42.44 mmol of (3-aminopropyl)trimethoxysilane was diluted with 3.61 mol of methanol. Concentrated nitric acid (65% by weight, 46.7 mmol) was rapidly added to the solution while vigorously stirring. Stirring was continued for 1 minute.

[0116] The ion-exchanged and acidified particle dispersion of Example 5 was vigorously stirred, and the newly prepared acidified aminosilane solution described above was quickly added. Stirring was continued at room temperature for 1 hour, and then the dispersion was heated to 70°C and stirred at that temperature for a further 2 hours.

[0117] Next, the dispersion was transferred to a rotary evaporator, where the alcohol was removed in stages and replaced by adding water until the dispersion reached a solids content of 21.5% by weight.

[0118] Finally, the dispersion was filtered through a 2 μm glass fiber filter.

[0119] The particles had an average particle size of 90.5 nm, a PDI of 0.058 as measured by DLS, and a zeta potential of 40.3 mV at pH 2.2.

[0120] Example 7: Synthesis of elongated particles with second growth (90% TEOS, 10% TMOS, ROR 0.75) 32.35 mol of anhydrous ethanol was mixed with 1.58 mol of tetraethoxysilane and 0.18 mol of tetramethoxysilane to obtain the first mixture. The first mixture was stirred and heated to 66°C. While stirring vigorously, 2.63 mol of ammonia solution (32%) was quickly added, and stirring was continued for 10 seconds before stopping. The temperature decreased to 60°C.

[0121] The reaction mixture was maintained at 60°C for 12 hours, and then the particle size was measured by DLS. The particles had an average particle size of 77.7 nm and a PDI of 0.054.

[0122] 25.53 mol of deionized water was heated to 60°C and then slowly added to the reaction mixture, which was still at 60°C, under stirring. Stirring was continued at 60°C for 30 minutes. Then, while continuing to stir, tetraethoxysilane (1.67 mol) was added over 3 hours using a dosimeter pump. Finally, the mixture was stirred at 60°C for 12 hours, and the particle size distribution was measured by DLS. The particles had an average particle size of 89.3 nm and a PDI of 0.047.

[0123] Comparative Example 1 (100% TEOS - not the present invention) A mixture of anhydrous ethanol (1,201.27 mmol) and tetraethoxysilane (TEOS) (50.00 mmol) was heated to 55°C with stirring. Ammonium hydroxide solution (32%, 74.78 mmol) was rapidly added while vigorously stirring. The temperature decreased to 50°C. Stirring was continued for 10 seconds, then the switch was turned off, and the reaction mixture was maintained at 50°C for 12 hours. The particle size distribution was then measured by DLS.

[0124] The particles had an average particle size of 47.4 nm and a PDI of 0.025.

[0125] A very low PDI indicates that the particles are not elongated or non-spherical, and therefore undesirable in terms of the required profile.

[0126] Example 8: Nitrogen level (or nitrogen content) As shown in Examples 1 and 2 above, the nitrogen level or nitrogen content in the non-spherical primary silica particles produced in the present invention was measured by dissolving the dried non-spherical primary silica particles in KOH, and then the nitrogen species were measured by ion chromatography. Before drying the particles, the dispersion medium was removed from the nitrogen-containing species by cross-flow filtration.

[0127] The results are shown in Table 1. [Table 1]

[0128] As is clear from the results shown in Table 1, even when a concentrated ammonia solution is used as a catalyst in the reaction, the nitrogen level in the non-spherical primary silica particles remains very low, in the range of 0.0041 to 0.0058 mmol / g SiO2.

[0129] This nitrogen content is based on U.S. Patent No. 9422456 and U.S. Patent No. 94997 No. 21 The nitrogen content incorporated into the silica particles disclosed in the specification was approximately 1 / 50th of that amount, and the nitrogen content was measured by the same method.

[0130] The nitrogen content in the non-spherical primary silica particles manufactured in this application is as specified in U.S. Patent No. 9,422,456 and U.S. Patent No. 9,4997. No. 21 The nitrogen content is less than (<0.02 mmol / g SiO2) than that measured from the particles used as a control in the specification.

[0131] The examples and descriptions of embodiments described herein should be interpreted as illustrative, not limiting, the invention as defined by the claims. For ease of understanding, numerous variations and combinations of the above-described features can be utilized without departing from the invention as described in the claims. Such variations are intended to be included within the following claims. Examples of embodiments of the present invention are listed in the following sections [Aspect 1] to [Aspect 27]. [Aspect 1] A method for synthesizing non-spherical primary silica nanoparticles, a) A step of providing a mixture of at least two organoalkoxysilanes, wherein each organoalkoxysilane independently has a structure represented by formula I, [ka] During the ceremony, R 1 、R 2 、R 3 , and R 4 Each is independently selected from the group consisting of OR or R, where R is a substituted or unsubstituted linear or branched C 1 ~C12 Alkyl alkyl group, C 3 ~C 8 Alicyclic group, C 2 ~C 6 It is an alkylene group, a halogen, or an aryl group, R 1 、R 2 、R 3 , and R 4 At least two of these, preferably at least three, are OR. At least one of the two organoalkoxysilanes is R 1 、R 2 、R 3 , and R 4 Having at least three of these, preferably all of them as OR, and The above-mentioned at least two organoalkoxysilanes have different reaction rates with water under alkaline conditions, and the steps are as follows: b) A step of providing a water-miscible organic solvent, c) A step of providing an alkaline catalyst, d) a) to c) step of obtaining a reaction mixture comprising water and water (H 2 The molar ratio (ROR) of O) to the hydrolyzable groups (OR) on the at least two organoalkoxysilanes is greater than 0 and less than 3.0, or less than 2.0, for example, given by the formula: ROR = M(H) 2 The step is 0.5 to 1.5 according to O) / M(OR), e) The step of forming non-spherical primary silica nanoparticles by reacting at least two organoalkoxysilanes with water in the reaction mixture under alkaline conditions, Optionally, f) After the non-spherical primary silica nanoparticles are formed, replace at least a portion of the water-miscible organic solvent with water to obtain a dispersion of non-spherical primary silica nanoparticles; g) If in step d) there is not enough water from a) to c) to satisfy the ROR, the step of adding water in step d), Methods that include... [Aspect 2] The non-spherical primary silica nanoparticles have shapes selected from the group consisting of elongated shapes, curved shapes, branched shapes, and combinations thereof, and have a molecular weight of <0.2, <0.1, <0.05, <0.02, <0.01, <0.006, <0.005, or <0.004 mmol / g SiO 2 The method according to embodiment 1, having a nitrogen level of [value]. [Aspect 3] The method according to embodiment 1, wherein step d) may be performed by (1) adding the water-miscible organic solvent to the mixture of at least two organoalkoxysilanes to obtain a first mixture, and adding the alkaline catalyst to the first mixture; (2) adding the alkaline catalyst to the water-miscible organic solvent to obtain a first mixture, and adding the mixture of at least two organoalkoxysilanes to the first mixture; or (3) adding the water-miscible organic solvent to the mixture of at least two organoalkoxysilanes to obtain a first mixture, adding the water-miscible organic solvent to the alkaline catalyst to obtain a second mixture, and mixing the first mixture and the second mixture in a mixer in a flow reactor. [Aspect 4] The method according to embodiment 1, wherein the first mixture and the reaction mixture are heated and maintained at a temperature of 30°C to 70°C, 40°C to 60°C, or 48°C to 52°C. [Aspect 5] The method according to embodiment 1, optionally carried out in a sealed container or a flow reactor under medium pressure. [Aspect 6] Each of the above at least two organoloxysilanes is tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraoctoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, octyltrimethoxysilane, octyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, The method according to embodiment 1, selected from the group consisting of phenyltriethoxysilane, triethylmethoxysilane, fluorotriisopropoxysilane, fluorotrimethoxysilane, fluorotriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, trimethylbutoxysilane, trifluoromethyltrimethoxysilane, and trifluoromethyltriethoxysilane. [Aspect 7] The method according to embodiment 1, wherein two organoalkoxysilanes are used in a mixture of at least two organoalkoxysilanes, one of the organoalkoxysilanes is present in an amount of about 50 to about 99 mol%, and the other organoalkoxysilane is present in an amount of about 50 to about 1 mol%. [Aspect 8] The method according to embodiment 1, wherein the at least two organoalkoxysilanes include tetramethoxysilane and tetraethoxysilane, and the tetramethoxysilane is present in an amount of about 2 to about 25 mol% or 7.5 to 12.5 mol% based on the total number of moles of the at least two organoalkoxysilanes. [Aspect 9] The above at least two organoalkoxysilanes include tetramethoxysilane and tetraethoxysilane, and water (H 2 The method according to embodiment 1, wherein the molar ratio (ROR) of O) and the hydrolyzable groups (OR) on at least two organoalkoxysilanes is 0.75. [Aspect 10] The aforementioned alkaline catalyst contains ammonia (NH₃). 3 The method according to embodiment 1, wherein a substance selected from the group consisting of ammonium hydroxide, organic amines, alkanolamines, quaternary ammonium hydroxide compounds, and combinations thereof. [Aspect 11] The method according to embodiment 1, wherein the pH of the reaction mixture is 7-14, 10-14, or 12-14. [Aspect 12] The aforementioned alkali catalyst is NH 3 The method according to embodiment 1, wherein the reaction mixture contains an organic amine and has a pH greater than 8 or greater than 9. [Aspect 13] The method according to embodiment 1, wherein step (d) is performed in a continuous flow reactor or a batch reactor. [Aspect 14] The aforementioned substitution step f) is water (H 2 The method according to embodiment 1, comprising the step of adding water in an amount such that the molar ratio (ROR) of O) to the hydrolyzable group (OR) on the organoalkoxysilane (ROR) is 1.0 or more or 2.0 or more. [Aspect 15] The method according to embodiment 1, further comprising a second growth step of adding an organoalkoxysilane, water, and optionally an alkaline catalyst to the reaction mixture immediately after step d). [Aspect 16] The method according to embodiment 1, wherein the substitution step f) includes at least one of distillation and membrane filtration. [Aspect 17] The method according to embodiment 1, further comprising the step of changing the pH of the non-spherical primary silica nanoparticle dispersion obtained in step f) from alkaline to acidic by passing the dispersion through an ion exchanger and optionally adding an acid. [Aspect 18] The method according to embodiment 1, further comprising the step of modifying the surface of the non-spherical primary silica nanoparticles by treating the surface with a surface modifier selected from the group consisting of organosilanes, organic polymers, inorganic polymers, surfactants, inorganic salts, metal ions, and combinations thereof. [Aspect 19] The method according to embodiment 18, wherein the organosilane used to modify the surface is selected from the group consisting of amino-functional alkyl-alkoxysilane, cyano-functional alkyl-alkoxysilane, alkyl and aryl-functional alkoxysilane, sulfur-containing silane, carboxyl-containing silane, phosphorus-containing silane, alkylsilane, and combinations thereof. [Aspect 20] The method according to Embodiment 1, wherein the non-spherical primary silica nanoparticles are produced in a weight% yield of 3.0% to 8.0% by weight, 4.0% to 7.0% by weight, 4.5% to 6.5% by weight, or 5.5% to 6.5% by weight, based on the total weight of silica nanoparticles that can be produced by the total weight of the reaction mixture. [Aspect 21] The method according to embodiment 1, wherein the non-spherical primary silica nanoparticles are produced in a yield of at least 50%, 75%, or 85% based on the total weight of the particles. [Aspect 22] Having a shape selected from the group consisting of elongated shapes, curved shapes, branched shapes, and combinations thereof, with a molecular weight of <0.2, <0.1, <0.05, <0.02, <0.01, <0.006, <0.005, or <0.004 mmol / g SiO 2 Non-spherical primary silica nanoparticles having a nitrogen level of [specified value]. [Aspect 23] Having a shape selected from the group consisting of elongated shapes, curved shapes, branched shapes, and combinations thereof, with a molecular weight of <0.2, <0.1, <0.05, <0.02, <0.01, <0.006, <0.005, or <0.004 mmol / g SiO 2 Non-spherical primary silica nanoparticles having a nitrogen level and prepared by the method described in any one of embodiments 1 to 21. [Aspect 24] Having a shape selected from the group consisting of elongated shapes, curved shapes, branched shapes, and combinations thereof, with a molecular weight of <0.2, <0.1, <0.05, <0.02, <0.01, <0.006, <0.005, or <0.004 mmol / g SiO 2 A chemomechanical planarization (CMP) composition comprising non-spherical primary silica nanoparticles having a nitrogen level of [specified value]. [Pattern 25] A chemical mechanical planarization (CMP) composition according to embodiment 24, further comprising at least one of a colloidal stabilizer, a soluble catalyst or solid catalyst, a chelating agent, a corrosion inhibitor, a surfactant, a biocide, an organic salt or inorganic salt, and a pH adjuster. [Aspect 26] A chemomechanical planarization (CMP) composition comprising non-spherical primary silica nanoparticles prepared by the method described in any one of embodiments 1 to 21. [Aspect 27] A chemical mechanical planarization (CMP) composition according to embodiment 26, further comprising at least one of a colloidal stabilizer, a soluble catalyst or solid catalyst, a chelating agent, a corrosion inhibitor, a surfactant, a biocide, an organic salt or inorganic salt, and a pH adjuster.

Claims

1. A method for synthesizing non-spherical primary silica nanoparticles, a) A step of providing a mixture of at least two organoalkoxysilanes, wherein each organoalkoxysilane independently has a structure represented by formula I, 【Chemistry 1】 During the ceremony, R １ 、R ２ 、R ３ 、and R ４ are each independently selected from the group consisting of OR or R, where R is a substituted or unsubstituted straight-chain or branched-chain C １ -C １２ alkyl group, C ３ -C ８ alicyclic group, C ２ -C ６ alkylene group, halogen, or aryl group, and at least two of １ R ２ 、R ３ 、and R ４ are OR At least one of the two organoalkoxysilanes is R １ , R ２ , R ３ , and R ４ It has at least three of the following as OR, and The above-mentioned at least two organoalkoxysilanes have different reaction rates with water under alkaline conditions, and the steps are as follows: b) A step of providing a water-miscible organic solvent, c) The step of providing an alkaline catalyst, d) A step of obtaining a reaction mixture comprising a) to c), wherein the reaction mixture contains water and water (H ２ The molar ratio (ROR) of O) and the hydrolyzable groups (OR) on the at least two organoalkoxysilanes is given by the formula: ROR = M(H) ２ A step that is greater than 0 and less than 3.0, or less than 2.0, according to O) / M(OR), e) The step of forming non-spherical primary silica nanoparticles by reacting at least two organoalkoxysilanes with water in the reaction mixture under alkaline conditions, f) If in step d) there is not enough water from a) to c) to satisfy the ROR, the step of adding water in step d), Includes, A method in which step d) can be carried out by (1) adding the water-miscible organic solvent to the mixture of at least two organoalkoxysilanes to obtain a first mixture, and adding the alkaline catalyst to the first mixture, or (2) adding the alkaline catalyst to the water-miscible organic solvent to obtain a first mixture, and adding the mixture of at least two organoalkoxysilanes to the first mixture all at once.

2. The non-spherical primary silica nanoparticles have shapes selected from the group consisting of elongated shapes, curved shapes, branched shapes, and combinations thereof, and have a molecular weight of <0.2, <0.1, <0.05, <0.02, <0.01, <0.006, <0.005, or <0.004 mmol / g SiO₂ ２ The method according to claim 1, having the nitrogen level of

3. The method according to claim 1, wherein the first mixture and the reaction mixture are heated and maintained at a temperature of 30°C to 70°C, 40°C to 60°C, or 48°C to 52°C.

4. The method according to claim 1, which is carried out in a sealed container or in a flow reactor.

5. Each of the above at least two organoloxysilanes is tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraoctoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, octyltrimethoxysilane, octyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, f The method according to claim 1, selected from the group consisting of phenyltriethoxysilane, triethylmethoxysilane, fluorotriisopropoxysilane, fluorotrimethoxysilane, fluorotriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, trimethylbutoxysilane, trifluoromethyltrimethoxysilane, and trifluoromethyltriethoxysilane.

6. The method according to claim 1, wherein two organoalkoxysilanes are used in a mixture of at least two organoalkoxysilanes, one of the organoalkoxysilanes is present in an amount of 50 to 99 mol%, and the other organoalkoxysilane is present in an amount of 50 to 1 mol%.

7. The method according to claim 1, wherein the at least two organoalkoxysilanes include tetramethoxysilane and tetraethoxysilane, and the tetramethoxysilane is present in an amount of 2 to 25 mol% or 7.5 to 12.5 mol% based on the total number of moles of the at least two organoalkoxysilanes.

8. The above at least two organoalkoxysilanes include tetramethoxysilane and tetraethoxysilane, and water (H ２ The method according to claim 1, wherein the molar ratio (ROR) of O) to the hydrolyzable groups (OR) on at least two organoalkoxysilanes is 0.

75.

9. The aforementioned alkaline catalyst contains ammonia (NH ３ The method according to claim 1, wherein a selected substance is from the group consisting of ), ammonium hydroxide, organic amines, alkanolamines, quaternary ammonium hydroxide compounds, and combinations thereof.

10. The method according to claim 1, wherein the pH of the reaction mixture is 7 to 14, 10 to 14, or 12 to 14.

11. The aforementioned alkali catalyst is NH ３ The method according to claim 1, wherein the reaction mixture comprises an organic amine and the pH of the reaction mixture is greater than 8 or greater than 9.

12. The method according to claim 1, wherein step (d) is performed in a continuous flow reactor or a batch reactor.

13. g) After the non-spherical primary silica nanoparticles are formed, replace at least a portion of the water-miscible organic solvent with water to obtain a dispersion of non-spherical primary silica nanoparticles; The method according to claim 1, further comprising:

14. The substitution step g) is water (H ２ The method according to claim 13, comprising the step of adding water in an amount such that the molar ratio (ROR) of O) to the hydrolyzable group (OR) on the organoalkoxysilane (ROR) is 1.0 or more or 2.0 or more.

15. The method according to claim 1, further comprising a second growth step of adding organoalkoxysilane and water to the reaction mixture immediately after step d).

16. The method according to claim 13, wherein the substitution step g) includes at least one of distillation and membrane filtration.

17. The method according to claim 13, further comprising the step of changing the pH of the non-spherical primary silica nanoparticle dispersion obtained in step g) from alkaline to acidic by passing the non-spherical primary silica nanoparticle dispersion through an ion exchanger.

18. The method according to claim 1, further comprising the step of modifying the surface of the non-spherical primary silica nanoparticles by treating the surface with a surface modifier selected from the group consisting of organosilanes, organic polymers, inorganic polymers, surfactants, inorganic salts, metal ions, and combinations thereof.

19. The method according to claim 18, wherein the organosilane used to modify the surface is selected from the group consisting of amino-functional alkyl-alkoxysilane, cyano-functional alkyl-alkoxysilane, alkyl and aryl-functional alkoxysilane, sulfur-containing silane, carboxyl-containing silane, phosphorus-containing silane, alkylsilane, and combinations thereof.

20. The method according to claim 1, wherein the non-spherical primary silica nanoparticles are produced in a weight% yield of 3.0% to 8.0% by weight, 4.0% to 7.0% by weight, 4.5% to 6.5% by weight, or 5.5% to 6.5% by weight, based on the total weight of silica nanoparticles that can be produced by the total weight of the reaction mixture.

21. The method according to claim 1, wherein the non-spherical primary silica nanoparticles are produced in a yield of at least 50%, 75%, or 85% based on the total weight of the particles.

22. A method for producing a chemomechanical planarization (CMP) composition, comprising the step of preparing non-spherical primary silica nanoparticles by the method described in any one of claims 1 to 21.

23. The method according to claim 22, further comprising the step of adding at least one of a colloidal stabilizer, a soluble catalyst or solid catalyst, a chelating agent, a corrosion inhibitor, a surfactant, a biocide, an organic salt or inorganic salt, and a pH adjuster to the non-spherical primary silica nanoparticles.

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