A slurry composition and electronic device

Abstract

The application relates to the technical field of surface treatment, in particular to a slurry combination liquid and an electronic device. The slurry combination liquid comprises abrasive, polymer A and polymer B, wherein the polymer B is a copolymer containing a sulfonic acid group-containing structural unit, and the polymer A and the polymer B have different sulfonic acid group-containing structural unit mass contents. The slurry combination liquid can realize a strong torque signal, thereby accurately controlling a torque stopping, accurately controlling a polishing endpoint, and meanwhile maintaining the stability of abrasive particle size of the slurry combination liquid after being mixed with an acidic slurry combination liquid, so as to reduce the agglomeration of the abrasive and avoid wafer scratching.

Description

Technical Field

[0001] This application relates to the field of surface treatment technology, specifically to a slurry combination liquid and electronic devices, particularly in the application of surface treatment of workpieces. Background Technology

[0002] With the continuous development of integrated circuit integration, shallow trench isolation (STI) technology has been widely used in integrated circuit manufacturing. STI structures play a role in device isolation within high-density transistors, and STI technology has become the mainstream isolation technology for the past decade. Chemical mechanical planarization (CMP) is recognized as the only globally planarization technology and is a crucial step in the STI structure manufacturing process, widely used in the manufacturing of advanced electronic products such as integrated circuit silicon wafers and optical glass. The CMP slurry is a key element in CMP, and cerium oxide slurry is currently the most commonly used slurry. During the STI planarization process, cerium oxide slurry is typically used for planarization, with the process stopped by adjusting the torque curve and halting when the polishing contacts the silicon nitride layer. Subsequently, an acidic slurry is used to remove the silicon nitride.

[0003] Current commercially available slurry combinations suffer from the following problems: They are difficult to control precisely using torque-based stop mechanisms, leading to either over- or under-planarization. During the removal of silicon nitride using acidic slurry combinations, residual slurry on the wafer surface comes into contact with the acidic slurry combination used for the second planarization process. This causes the surface dispersant in the abrasive within the slurry combination to detach, forming agglomerates. Large agglomerates can scratch the wafer during planarization, affecting device performance. Existing polymer-containing slurry combinations exhibit low frictional torque when in contact with silicon nitride, making torque-based stop mechanisms insufficient to determine the planarization endpoint, resulting in either over- or under-planarization. Furthermore, related technologies struggle to simultaneously address low planarization defects and high-torque stop mechanisms. Summary of the Invention

[0004] This application discloses a slurry combination liquid and electronic devices to solve the problem of over-planarization or under-planarization caused by the difficulty in accurately controlling torque gripping, while also avoiding the formation of agglomerates during the planarization process that cause wafer scratches.

[0005] In a first aspect, this application provides a slurry composition comprising: an abrasive, polymer A, polymer B, and a dispersant, wherein polymer B is a copolymer containing structural units with sulfonic acid groups, and the mass content of structural units with sulfonic acid groups in polymer A is different from the mass content of structural units with sulfonic acid groups in polymer B.

[0006] The slurry mixture provided in this application contains polymer A and polymer B. This allows the slurry mixture to obtain a strong torque signal, thereby precisely controlling torque stopping and accurately determining the leveling endpoint. Simultaneously, it maintains the stability of the abrasive particle size after mixing with the acidic slurry mixture, thus reducing abrasive agglomeration and wafer scratching.

[0007] In one possible implementation, the mass content of sulfonic acid group-containing structural units in polymer A is less than the mass content of sulfonic acid group-containing structural units in polymer B.

[0008] In one possible implementation, the mass content of sulfonic acid-containing structural units in polymer A differs from that in polymer B by 1% to 90%.

[0009] In one possible implementation, the mass content of sulfonic acid-containing structural units in polymer A differs from that in polymer B by 3% to 90%, 5% to 90%, 40-60%, or 50%.

[0010] In one possible implementation, the mass percentage of sulfonic acid-containing structural units in polymer B is 5-90%, 40-60%, or 50% based on the total mass of polymer B.

[0011] In one possible implementation, based on the total mass of the monomers used to form polymer B, the mass percentage of sulfonic acid type monomers included in the monomers used to form polymer B is 5% to 90%, 40-60%, or 50%, wherein the sulfonic acid type monomers are monomers containing sulfonic acid groups, monomers containing sulfonates, or combinations thereof. When the monomers used to form polymer B contain both monomers containing sulfonic acid groups and monomers containing sulfonates, the mass percentage of sulfonic acid type monomers is the sum of the mass percentages of the monomers containing sulfonic acid groups and the monomers containing sulfonates present.

[0012] In one possible implementation, polymer B is a copolymer of monomers comprising a monomer containing a carboxylic acid functional group and a sulfonic acid type monomer.

[0013] In one possible implementation, polymer B is a copolymer of a monomer containing a carboxylic acid functional group and a sulfonic acid monomer.

[0014] In one possible implementation, the monomer containing a carboxylic acid functional group is selected from olefin monomers containing a carboxylic acid functional group.

[0015] In one possible implementation, the monomer containing a carboxylic acid functional group is selected from one or more of the following: acrylic acid monomers, butenoic acid monomers, and maleic acid monomers.

[0016] In one possible implementation, the monomer containing the carboxylic acid functional group is selected from acrylic acid and its salts, butenoic acid and its salts, methacrylic acid and its salts, ethylacrylic acid and its salts, methylbutenoic acid and its salts, ethylbutenoic acid and its salts, and maleic anhydride.

[0017] In one possible implementation, the sulfonic acid monomer is selected from alkyl sulfonic acids, alkenyl sulfonic acids, alkynyl sulfonic acids, aromatic sulfonic acids, amide sulfonic acids, or their salts.

[0018] In one possible implementation, the sulfonic acid monomer is selected from styrenesulfonic acid and 2-acrylamide-2-methylpropanesulfonic acid.

[0019] In one possible implementation, polymer B is formed by copolymerizing acrylic acid with styrene sulfonic acid or 2-acrylamide-2-methylpropanesulfonic acid.

[0020] In one possible implementation, polymer A or B is a terpolymer.

[0021] In the slurry mixture provided in this application embodiment, preferably based on the total mass of the monomers used to form polymer B, the mass percentage of sulfonic acid monomers is 5% to 90%, and polymer B is a copolymer of monomers containing carboxylic acid functional groups and sulfonic acid monomers. This can maintain a high stability of the abrasive particle size after the slurry mixture is mixed with the acidic slurry mixture, thereby reducing abrasive agglomeration and avoiding wafer scratches.

[0022] In one possible implementation, based on the total mass of polymer A, the mass percentage of sulfonic acid-containing structural units in polymer A is 0 to <5%, ≤3%, or ≤1%.

[0023] In one possible implementation, based on the total mass of the monomers used to form polymer A, the mass percentage of the sulfonic acid type monomer is <5%, ≤3%, or ≤1%, wherein the sulfonic acid type monomer is a monomer containing a sulfonic acid group, a monomer containing a sulfonate, or a combination thereof. When the monomers used to form polymer A contain both a monomer containing a sulfonic acid group and a monomer containing a sulfonate, the mass percentage of the sulfonic acid type monomer is the sum of the mass percentages of the monomers containing sulfonic acid groups and the monomers containing sulfonates present.

[0024] In one possible implementation, polymer A does not contain structural units containing sulfonic acid groups.

[0025] In one possible implementation, polymer A is a monomer.

[0026] In one possible implementation, polymer A is selected from polymers containing carboxylic acid functional groups.

[0027] In one possible implementation, polymer A is selected from olefin polymers containing carboxylic acid functional groups.

[0028] In one possible implementation, polymer A is selected from one or more of the following: polyacrylic acid or a salt thereof, hydrolyzed or partially hydrolyzed polymaleic anhydride or a salt thereof, polymaleic acid or a salt thereof, polymethacrylic acid or a salt thereof.

[0029] In one possible implementation, polymer A is polyacrylic acid, or a combination of polyacrylic acid and polymaleic acid.

[0030] In one possible implementation, the mass ratio of polymer A to polymer B is 0.1 to 10.

[0031] In one possible implementation, the mass ratio of polymer A to polymer B is 1 to 5.

[0032] In one possible implementation, the mass ratio of polymer A to polymer B is 5.

[0033] In the slurry mixture provided in this application embodiment, when the mass ratio of polymer A to polymer B is in the range of 0.1 to 10, the slurry mixture exhibits a strong torque signal.

[0034] In one possible implementation, the abrasive is selected from cerium oxide, silicon dioxide, aluminum oxide, or a combination thereof.

[0035] In one possible implementation, the abrasive is cerium oxide particles.

[0036] In one possible implementation, the abrasive is cerium oxide nanoparticles.

[0037] In one possible implementation, the cerium oxide nanoparticles have a particle size of 60 nm to 200 nm.

[0038] In one possible implementation, the cerium oxide nanoparticles have a particle size of 110 nm to 150 nm.

[0039] In the slurry combination solution provided in this application embodiment, when the particle size of cerium oxide nanoparticles is in the range of 60 nm to 200 nm, the particle size of cerium oxide nanoparticles can be kept stable after the slurry combination solution is mixed with the acidic slurry combination solution, reducing agglomeration and thus reducing wafer scratches.

[0040] In one possible implementation, polymer B is at least partially coated on the surface of the abrasive.

[0041] In one possible implementation, polymer B is uniformly coated on the surface of the abrasive.

[0042] In one possible implementation, the dispersant is water.

[0043] In one possible implementation, the slurry mixture also includes a pH adjuster.

[0044] In one possible implementation, the slurry mixture further comprises an acid or base, such as an organic acid, an inorganic acid, an organic base, or an inorganic base.

[0045] In one possible implementation, the slurry mixture contains 0.1-3 wt% or 1-2.4 wt% abrasive, based on the total weight of the slurry mixture.

[0046] In one possible implementation, the slurry mixture contains 0.01-1 wt%, 0.05-0.5 wt%, or 0.1-0.2 wt% of polymer A, based on the total weight of the slurry mixture.

[0047] In one possible implementation, the slurry mixture contains 0.01-1 wt%, 0.02-0.1 wt%, or 0.02-0.05 wt% of polymer B, based on the total weight of the slurry mixture.

[0048] Secondly, this application provides an electronic device including a functional layer, the surface of which is smoothed by a slurry mixture solution as described in the embodiments of this application.

[0049] Therefore, the above-mentioned technical features of this application have the following beneficial effects:

[0050] The slurry combination solution of this application can achieve precise control of torque stopping, while maintaining the stability of abrasive particle size after the slurry combination solution is mixed with acidic slurry combination solution, thereby reducing abrasive agglomeration and avoiding wafer scratching.

[0051] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Detailed Implementation

[0052] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0053] definition

[0054] The term "hydrocarbon group" as used alone or in combination in this article refers to a group consisting only of carbon and hydrogen atoms.

[0055] The term “alkyl” as used alone or in combination herein refers to a straight-chain or branched saturated hydrocarbon group, such as a straight-chain or branched saturated hydrocarbon group having 1 to 60, 1-40, 1-20, or 1-10 carbon atoms, such as methyl, ethyl, propyl, or isopropyl.

[0056] The term "alkenyl" as used alone or in combination in this article refers to a straight-chain or branched unsaturated hydrocarbon group containing at least one carbon-carbon double bond, such as a straight-chain or branched saturated hydrocarbon group with 1 to 60, 1 to 40, 1 to 20, or 1 to 10 carbon-carbon double bonds, such as ethylene, propylene, isopropylene, or butene.

[0057] The term "alkynyl" as used alone or in combination in this article refers to a straight-chain or branched unsaturated hydrocarbon group containing at least one carbon-carbon triple bond, such as a straight-chain or branched saturated hydrocarbon group with 1 to 60, 1-40, 1-20, or 1-10 carbon-carbon triple bonds, such as acetylene, propyne, or butyne.

[0058] The term "aryl" as used alone or in combination in this article refers to a group containing any carbon-based aromatic ring, such as an aryl group having 1 to 60, 1 to 40, 1 to 20, or 1 to 10 carbon atoms.

[0059] The term "sulfonic acid" as used alone or in combination in this article is R-SO3H, which is a compound in which a sulfonyl group is attached to a hydrocarbon group (including the aryl group as described above).

[0060] The term “olefin monomers containing carboxylic acid functional groups” as used in this article refers to organic compounds that simultaneously possess carbon-carbon double bonds (C=C) and carboxyl groups (—COOH), such as acrylic acid and its derivatives.

[0061] In surface treatment technologies, such as STI planarization, a slurry mixture is typically used for planarization. Planarization is stopped by monitoring changes in the torque curve, specifically when the slurry mixture contacts the silicon nitride layer. Subsequently, an acidic slurry mixture is used to remove the silicon nitride. During this process, any slurry mixture remaining on the wafer surface comes into contact with the acidic slurry mixture used in the second planarization step.

[0062] Some embodiments of this application provide a slurry composition comprising: an abrasive, polymer A, and polymer B, wherein polymer B is a copolymer containing sulfonic acid-containing structural units, and polymer A and polymer B have different mass contents of sulfonic acid-containing structural units.

[0063] As shown, this application uses polymer B, which contains sulfonic acid group structural units, and adds another polymer A, which has a different mass content of sulfonic acid group structural units than polymer B, to the slurry mixture. This ensures the dispersion stability of the abrasive in the solution, realizes a strong torque signal, and thus accurately controls the torque stop, accurately judges the leveling endpoint, and maintains the stability of the abrasive particle size after the slurry mixture is mixed with the acidic slurry mixture, thereby reducing abrasive agglomeration and avoiding wafer scratches.

[0064] In some embodiments of this application, the mass content of sulfonic acid-containing structural units in polymer A is less than the mass content of sulfonic acid-containing structural units in polymer B. For example, the mass content of sulfonic acid-containing structural units in polymer A differs from that in polymer B by 1% to 90%, 3% to 90%, 5% to 90%, 10% to 80%, 20% to 70%, 40-60%, or 50%.

[0065] In some embodiments of this application, the mass percentage of sulfonic acid-containing structural units in polymer B is 5-90%, 40-60%, or 50% based on the total mass of polymer B. For example, the content of sulfonic acid-containing structural units in polymer B is 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% based on the total weight of polymer B, including any of the values ​​mentioned above.

[0066] In some embodiments of this application, based on the total mass of the monomers used to form polymer B, the mass percentage of sulfonic acid type monomers contained in the monomers used to form polymer B is 5% to 90%, 40-60%, or 50%, wherein the sulfonic acid type monomers are monomers containing sulfonic acid groups, monomers containing sulfonates, or combinations thereof. When the monomers used to form polymer B contain both monomers containing sulfonic acid groups and monomers containing sulfonates, the mass percentage of sulfonic acid type monomers is the sum of the mass percentages of the monomers containing sulfonic acid groups and the mass percentages of the monomers containing sulfonates present.

[0067] For example, based on the total mass of the monomers used to form polymer B, the mass percentage of sulfonic acid monomers contained in the monomers used to form polymer B is 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, including any of the above values.

[0068] In some embodiments of this application, polymer B is a copolymer of monomers containing a monomer with a carboxylic acid functional group and a sulfonic acid type monomer.

[0069] In some embodiments of this application, polymer B is a copolymer of a monomer containing a carboxylic acid functional group and a sulfonic acid type monomer.

[0070] In some embodiments of this application, the monomer containing a carboxylic acid functional group is selected from olefinic monomers containing a carboxylic acid functional group. Exemplarily, the monomer containing a carboxylic acid functional group is selected from one or more of the following: acrylic acid monomers, butenoic acid monomers, and maleic acid monomers. In a preferred embodiment, the monomer containing a carboxylic acid functional group is selected from acrylic acid and its salts, butenoic acid and its salts, methacrylic acid and its salts, ethylacrylic acid and its salts, methylbutenoic acid and its salts, ethylbutenoic acid and its salts, and maleic anhydride.

[0071] In some embodiments of this application, the sulfonic acid monomer is selected from alkyl sulfonic acids, alkenyl sulfonic acids, alkynyl sulfonic acids, aromatic sulfonic acids, amide sulfonic acids, or salts thereof. For example, the sulfonic acid monomer is selected from styrene sulfonic acid and 2-acrylamido-2-methylpropanesulfonic acid.

[0072] For example, polymer B is formed by copolymerization of acrylic acid with styrene sulfonic acid or 2-acrylamide-2-methylpropanesulfonic acid.

[0073] Preferably, based on the total mass of the monomers used to form polymer B, the mass percentage of sulfonic acid monomers is 5% to 90%, and polymer B is a copolymer of monomers containing monomers with carboxylic acid functional groups and monomers containing sulfonic acid groups and / or sulfonates. This can maintain better stability of the abrasive particle size after the slurry mixture is mixed with the acidic slurry mixture, thereby reducing abrasive agglomeration and avoiding wafer scratches.

[0074] In some embodiments of this application, the mass percentage of sulfonic acid groups in polymer A is 0 to <5%, ≤3%, or ≤1%, based on the total weight of polymer A. For example, the mass percentage in polymer A is 0, 1%, 2%, 3%, 4%, or <5%, including any of the values ​​mentioned above, based on the total weight of polymer A.

[0075] In some embodiments of this application, based on the total mass of the monomers used to form polymer A, the mass percentage of sulfonic acid type monomers is <5%, ≤3%, or ≤1%, wherein the sulfonic acid type monomers are monomers containing sulfonic acid groups, monomers containing sulfonates, or combinations thereof. When the monomers used to form polymer A contain both monomers containing sulfonic acid groups and monomers containing sulfonates, the mass percentage of sulfonic acid type monomers is the sum of the mass percentages of the monomers containing sulfonic acid groups and the monomers containing sulfonates present.

[0076] For example, based on the total mass of the monomers used to form polymer A, the mass percentage of monomers containing sulfonic acid groups or sulfonates is <5%, ≤4%, ≤3%, ≤2%, ≤1%, or 0, including any of the above values.

[0077] In some embodiments of this application, polymer A does not contain structural units containing sulfonic acid groups. In still other embodiments of this application, polymer A is a monomer. In yet another embodiment of this application, polymer A is selected from polymers containing carboxylic acid functional groups. Exemplarily, polymer A is selected from olefin polymers containing carboxylic acid functional groups. Preferably, polymer A is selected from one or more of the following: polyacrylic acid or a salt thereof, hydrolyzed or partially hydrolyzed polymaleic anhydride or a salt thereof, polymaleic acid or a salt thereof, polymethacrylic acid or a salt thereof. More preferably, polymer A is polyacrylic acid, or a combination of polyacrylic acid and polymaleic acid.

[0078] In some embodiments of this application, the mass ratio of polymer A to polymer B is from 0.1 to 10. In still other embodiments of this application, the mass ratio of polymer A to polymer B is from 1 to 5, preferably 5. Exemplarily, the mass ratio of polymer A to polymer B is 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, including any of the values ​​mentioned above.

[0079] When the mass ratio of polymer A to polymer B is in the range of 0.1 to 10, the slurry mixture exhibits a strong torque signal during the leveling process.

[0080] In some embodiments of this application, the abrasive is selected from cerium oxide, silicon dioxide, aluminum oxide, or combinations thereof. Preferably, the abrasive is cerium oxide particles, and more preferably, the abrasive is cerium oxide nanoparticles.

[0081] In some embodiments of this application, the cerium oxide nanoparticles have a particle size of 60 nm to 200 nm. Preferably, the cerium oxide nanoparticles have a particle size of 110 nm to 150 nm.

[0082] For example, the particle size of cerium oxide particles is 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, including any of the above values.

[0083] When the particle size of cerium oxide particles is in the range of 60 nm to 200 nm, the particle size stability of cerium oxide nanoparticles can be better maintained after the slurry mixture is mixed with the acidic slurry mixture, reducing agglomeration and thus reducing wafer scratches.

[0084] In some embodiments of this application, polymer B at least partially coats the surface of the abrasive. Preferably, polymer B uniformly coats the surface of the abrasive.

[0085] In some embodiments of this application, the slurry mixture further comprises a dispersant. Preferably, the dispersant is water.

[0086] In some embodiments of this application, the slurry composition further comprises a pH adjuster, such as an acid or a base. Exemplarily, the slurry composition further comprises organic acids, inorganic acids, or combinations thereof. Exemplarily, the slurry composition further comprises organic bases, inorganic bases, or combinations thereof. Exemplarily, the slurry composition further comprises hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, oxalic acid, citric acid, salicylic acid, pyruvic acid, or combinations thereof. Exemplarily, the slurry composition further comprises sodium hydroxide, calcium hydroxide, potassium carbonate, sodium bicarbonate, sodium methoxide, butyllithium, tetramethylammonium hydroxide, or combinations thereof.

[0087] In some embodiments of this application, the slurry composition contains 0.1-3 wt% abrasive based on the total weight of the slurry composition. For example, the abrasive content in the slurry composition is 0.1 wt%, 0.5 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, 2 wt%, 2.4 wt%, or 3 wt%, including any of the values ​​mentioned above, based on the total weight of the slurry composition.

[0088] In some embodiments of this application, the slurry composition contains 0.01-1 wt% polymer A based on the total weight of the slurry composition. For example, the content of polymer A in the slurry composition is 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.15%, 0.2 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.8 wt%, or 1 wt%, including any of the values ​​mentioned above.

[0089] In some embodiments of this application, the slurry composition contains 0.01-1 wt% polymer B based on the total weight of the slurry composition. For example, the content of polymer B in the slurry composition is 0.01 wt%, 0.02 wt%, 0.05 wt%, 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt%, or 1 wt%, including any of the values ​​mentioned above.

[0090] For example, based on the total weight of the slurry mixture, the slurry mixture contains: 1.2 wt% abrasive, 0.1 wt% polymer A, and 0.02 wt% polymer B.

[0091] Some embodiments of this application provide a method for preparing the slurry mixture of this application, the method comprising the following steps: mixing abrasive, polymer A, polymer B and dispersant to obtain the slurry mixture.

[0092] In some embodiments of this application, the method further includes adjusting the pH of the resulting mixture to 4.5-5, preferably pH 5.

[0093] Some embodiments of this application provide a slurry mixture prepared according to the above-described method for preparing a slurry mixture of this application.

[0094] Some embodiments of this application provide a surface treatment method for a workpiece, which includes smoothing the workpiece using the slurry combination liquid of this application.

[0095] In some embodiments of this application, the workpiece includes silicon oxide as a layer to be leveled and silicon nitride as a leveling stop layer, and a slurry mixture is used to level the silicon oxide.

[0096] In some embodiments of this application, the workpiece is a material layer in a semiconductor device.

[0097] In some embodiments of this application, the workpiece is a dielectric layer in a shallow trench isolation (STI) structure.

[0098] The slurry combination solution of this application is used to perform leveling treatment on the workpiece, ensuring the dispersion stability of the abrasive in the solution, realizing a strong torque signal, thereby accurately controlling the torque stop, accurately judging the leveling point, and maintaining the stability of the abrasive particle size after the slurry combination solution is mixed with the acidic slurry combination solution, thereby reducing abrasive agglomeration and avoiding workpiece scratches.

[0099] Some embodiments of this application provide an electronic device including a functional layer whose surface is smoothed by a slurry mixture as described in the embodiments of this application.

[0100] The technical solutions provided in this application will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of this application.

[0101] In the following examples and comparative examples, all chemical reagents used were of analytical grade; all raw materials could be purchased from chemical reagent companies or biopharmaceutical companies; and the stirring was carried out using a magnetic stirrer.

[0102] In the following examples and comparative examples, all percentages are by mass unless otherwise specified. Furthermore, the polymers can be prepared according to the methods described in U.S. Patent No. 2,289,540 or in Zahran et al., “Poly Acrylic Acid: Synthesis, Aqueous Properties and their Applications as Scale Inhibitor,” for example, by the self-polymerization of acrylic acid or by the free radical polymerization of acrylic acid with comonomers. The polymers in the examples and comparative examples have a molecular weight of 1,000-20,000, preferably 10,000.

[0103] Example 1

[0104] At room temperature, 1.2 wt% of commercially available nano-cerium oxide particles were added to water and mixed thoroughly. Then, the following polymer A was added: 0.1 wt% polyacrylic acid and 0.02 wt% acrylic acid and styrene sulfonic acid copolymer B. The mixture was thoroughly mixed and then the pH was adjusted to 5 with sodium hydroxide. The content of sulfonic acid monomer in the monomer used to form copolymer B was 5%.

[0105] Example 2

[0106] Except that the sulfonic acid monomer content in the monomer used to form copolymer B is 50%, the other conditions are the same as in Example 1.

[0107] Example 3

[0108] Except that the sulfonic acid monomer content in the monomer used to form copolymer B is 90%, the other conditions are the same as in Example 1.

[0109] Example 4

[0110] At room temperature, 1.2 wt% of commercially available nano-cerium oxide particles are added to water and mixed thoroughly. Then, the following polymer A is added: 0.1 wt% polyacrylic acid and 0.05 wt% polymaleic acid, and 0.05 wt% acrylic acid and styrene sulfonic acid copolymer B. The mixture is thoroughly mixed and then the pH is adjusted to 5 with sodium hydroxide. The sulfonic acid monomer content in the monomers used to form copolymer B is 50%.

[0111] Example 5

[0112] At room temperature, 2.4 wt% of commercially available nano-cerium oxide particles were added to water and mixed thoroughly. Then, the following polymer A was added: 0.1 wt% polyacrylic acid and 0.05 wt% acrylic acid-styrene sulfonic acid copolymer B. The mixture was thoroughly mixed and then the pH was adjusted to 5 with sodium hydroxide. The sulfonic acid monomer content in the monomers used to form copolymer B was 50%.

[0113] Example 6

[0114] Except for the amount of acrylic acid and styrene sulfonic acid copolymer B being 0.1 wt%, the other conditions were the same as in Example 2.

[0115] Example 7

[0116] Except for the amount of polymer A: polyacrylic acid, which is 0.2 wt%, the other conditions are the same as in Example 6.

[0117] Example 8

[0118] At room temperature, add 1.2 wt% of commercially available nano-cerium oxide particles to water, mix and stir evenly, then add the following polymer A: 0.1 wt% polyacrylic acid and 0.1 wt% acrylic acid and acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer B, mix thoroughly, and then adjust the pH to 5 with sodium hydroxide, wherein the sulfonic acid monomer content in copolymer B is 50%.

[0119] Comparative Example 1

[0120] At room temperature, add 1.2 wt% commercially available nano-cerium oxide particles to water, mix and stir evenly, then add 0.1 wt% polyacrylic acid, mix thoroughly, and then adjust the pH to 5 with sodium hydroxide.

[0121] Comparative Example 2

[0122] Except for the amount of polyacrylic acid being 0.2 wt%, the other conditions were the same as those in Comparative Example 1.

[0123] Comparative Example 3

[0124] At room temperature, 1.2 wt% of commercially available nano-cerium oxide particles were added to water and mixed thoroughly. Then, 0.2 wt% of acrylic acid and styrene sulfonic acid copolymer B was added and mixed thoroughly. The pH was then adjusted to 5 with sodium hydroxide. The sulfonic acid monomer content in copolymer B was 50%.

[0125] Comparative Example 4

[0126] At room temperature, add 1.2 wt% commercially available nano-cerium oxide particles to water, mix and stir evenly, then add 0.2 wt% styrenesulfonic acid, mix thoroughly, and then adjust the pH to 5 with sodium hydroxide.

[0127] Performance testing:

[0128] 1. Particle size determination

[0129] The particle size X of cerium oxide particles in the slurry mixtures of Examples 1 to 8 and Comparative Examples 1 to 4 was determined using a laser particle size analyzer (Malvin Instruments Ltd., 3000HSA). The results are shown in Table 1.

[0130] In addition, the slurry combination liquids of Examples 1 to 8 and Comparative Examples 1 to 4 were mixed with the acidic slurry combination liquid DTS9001 at a volume ratio of 1:10. After mixing, the particle size Y of the mixed cerium oxide particles was measured using a laser particle size analyzer, and the results are shown in Table 1.

[0131] The increase in cerium oxide particle size after mixing with acidic slurry was obtained by calculating the ratio of particle size X to particle size Y. The results are shown in Table 1.

[0132] 2. Torque Measurement

[0133] The workpiece is, for example, a workpiece produced by the following method: the critical dimension of the planarized pattern is 18 micrometers, a 100 nm thick silicon nitride layer is deposited on a 300 mm thick silicon wafer, a 100 nm deep groove is formed by etching, and then a 300 nm thick silicon oxide layer is deposited on the wafer.

[0134] Torque signals were measured using a Universal-300B polisher (Huahai Qingke). Leveling was performed on a 12-inch leveling stage, on a DH3002 leveling pad, at a pressure of 2 psi, a head / disc speed of 87 / 93 rpm, and a slurry flow rate of 300 ml / min. Leveling patterns were created using the slurry combinations from Examples 1 to 8 and Comparative Examples 1 to 4, and the pattern was leveled for 3 minutes. Torque curves were collected. Table 1 shows the strength of the torque signals. The torque signals exhibited the following changes: 1. Initially rising to torque a; 2. Stabilizing; 3. Rapidly rising to peak torque b; 4. Rapidly decreasing to a low point torque c; 5. Stabilizing. The strength of the torque signal was represented as follows: strong when torque (bc) / b ≥ 20, medium when 20 > (bc) / b > 5, and weak when (bc) / b ≤ 5.

[0135] Table 1 shows the torque signal, particle size X, particle size Y, and the increase ratio X / Y of the particle size.

[0136]

[0137] As shown in Comparative Examples 1 and 2 above, while a strong torque signal can be obtained when using a slurry mixture without polymer B for leveling, the particle size of cerium oxide particles increases significantly after mixing with the acidic slurry mixture, increasing the possibility of cerium oxide particle agglomeration and wafer scratching. As shown in Comparative Examples 3 and 4 above, although the particle size of cerium oxide particles is stable after mixing with the acidic slurry mixture when using a slurry mixture without polymer A for leveling, the torque signal is weak, making it impossible to accurately determine the leveling endpoint.

[0138] Furthermore, the analysis of Examples 1 to 8 shows that when polymer A and polymer B are present in the slurry mixture, a better torque signal can be obtained, the leveling endpoint can be accurately determined, and the stability of the cerium oxide particle size is increased, reducing the possibility of cerium oxide particle agglomeration, thereby reducing the possibility of scratching the wafer.

[0139] The above-described preferred embodiments have further detailed the purpose, technical solutions, and advantages of this application. It should be understood that the above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A slurry mixture, characterized in that, The slurry mixture comprises: abrasive, dispersant, polymer A, and polymer B; The polymer B is a copolymer containing sulfonic acid group-containing structural units, and the mass content of sulfonic acid group-containing structural units in polymer A differs from the mass content of sulfonic acid group-containing structural units in polymer B. The mass ratio of polymer A to polymer B is 2 to 5. Polymer B is formed by copolymerizing acrylic acid with styrene sulfonic acid or 2-acrylamide-2-methylpropanesulfonic acid. Based on the total mass of polymer B, the mass percentage of sulfonic acid-containing structural units in polymer B is 5-90%. The polymer A is polyacrylic acid, or a combination of polyacrylic acid and polymaleic acid. Wherein, based on the total weight of the slurry mixture, the slurry mixture contains: 1-3 wt% abrasive; 0.05-0.15 wt% of polymer A; and 0.02-0.05 wt% of polymer B.

2. The slurry mixture according to claim 1, characterized in that, Based on the total mass of polymer B, the mass percentage of sulfonic acid group-containing structural units in polymer B is 40-60%.

3. The slurry mixture according to claim 2, characterized in that, Based on the total mass of polymer B, the mass percentage of sulfonic acid group-containing structural units in polymer B is 50%.

4. The slurry mixture according to claim 1, characterized in that, Based on the total mass of the monomers used to form the polymer B, the mass percentage of sulfonic acid monomers contained in the monomers used to form the polymer B is between 5% and 90%.

5. The slurry mixture according to claim 4, characterized in that, The monomers used to form polymer B contain 40% to 60% by mass of sulfonic acid monomers.

6. The slurry mixture according to claim 4, characterized in that, The monomers used to form polymer B contain 50% by mass of sulfonic acid monomers.

7. The slurry mixture according to claim 1, characterized in that, The abrasive is selected from cerium oxide, silicon dioxide, aluminum oxide, or a combination thereof.

8. The slurry mixture according to claim 7, characterized in that, The abrasive is cerium oxide particles.

9. The slurry mixture according to claim 8, characterized in that, The abrasive is cerium oxide nanoparticles.

10. The slurry mixture according to claim 8, characterized in that, The abrasive is cerium oxide nanoparticles with a particle size of 60-200 nm.

11. The slurry mixture according to claim 10, characterized in that, The cerium oxide nanoparticles have a particle size of 110-150 nm.

12. The slurry mixture according to claim 1, characterized in that, The polymer B at least partially coats the surface of the abrasive.

13. The slurry mixture according to claim 1, characterized in that, The polymer B is uniformly coated on the surface of the abrasive.

14. The slurry mixture according to claim 1, characterized in that, The dispersant is water.

15. The slurry mixture according to claim 1, characterized in that, Based on the total weight of the slurry mixture, the slurry mixture contains 1-2.4 wt% abrasive.

16. An electronic device, characterized in that, The electronic device includes a functional layer, the surface of which is polished using a slurry combination liquid as described in any one of claims 1-15.

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