Polishing composition and method for performing material removal operations

Abstract

The abrasive composition may contain an aluminum(III) salt, a permanganate, and water, the amount of permanganate may be at least 2.5% by weight based on the total weight of the abrasive composition, the amount of aluminum(III) salt may be at least 0.2% by weight based on the total weight of the abrasive composition, and the pH of the composition is 4.5 or less.

Description

[Technical Field]

[0001] This disclosure relates to an abrasive composition for performing a material removal operation, specifically an abrasive composition comprising an aluminum(III) salt and a permanganate, and a method for performing a material removal operation. [Background technology]

[0002] Polishing compositions, which assist in polishing processes, such as polishing substrates using polishing pads, have a wide variety of applications, for example, for polishing glass, ceramic, or metallic materials, and are often designed for use in chemical mechanical planarization (CMP) processes. In a typical CMP process, the relative motion of the slurry to the substrate being polished interacts chemically and mechanically with the outer surface of the substrate, assisting the planarization (polishing) process by removing unwanted material. Polishing is continued until a desired smooth outer surface with low surface roughness is obtained. There is a need to develop cost-effective polishing compositions that can contribute to a high material removal rate during polishing and result in a polished substrate with low surface roughness. [Modes for carrying out the invention]

[0003] As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” or any other variations thereof, are intended to encompass non-exclusive inclusion. For example, a process, method, article, or apparatus that includes a list of features is not necessarily limited to those features alone and may include other features not expressly enumerated or that are inherent to such process, method, article, or apparatus.

[0004] Where used herein, unless otherwise clearly stated, “or” means an inclusive “or” and not an exclusive “or.” For example, condition A or B is satisfied by any one of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0005] Furthermore, the use of “one (a)” or “one (an)” is used to describe the elements and components described herein. This is done solely for convenience and to give a general sense of the scope of the invention. This description should be read as including one or at least one, and the singular also includes the plural unless it is clear that it does not.

[0006] This disclosure relates to abrasive compositions adapted for performing material removal operations. The composition may comprise at least 2.5% by weight of a permanganate, at least 0.2% by weight of an aluminum(III) salt, and water, and the pH of the abrasive composition may be 4.5 or less. Surprisingly, the abrasive compositions of this disclosure have been observed to be able to polish silicon carbide-containing substrates with high material removal rates and desired low surface roughness.

[0007] In a particular embodiment, the abrasive composition of the Disclosure may not essentially contain abrasive particles. As used herein, "essentially free of abrasive particles" means that the amount of abrasive particles is 0.1% by weight or less, or 0.05% by weight or less, or 0.01% by weight or less. In another embodiment, the abrasive composition may not contain abrasive particles except for unavoidable impurities.

[0008] Surprisingly, it was observed that the efficiency of potassium permanganate as an oxidizing agent could be significantly improved when aluminum(III) salt was further included in the polishing slurry composition. While not bound by theory, it is thought that a synergistic effect can be obtained between permanganate ions and aluminum(III) salt when chemically altering the surface of the substrate material during polishing.

[0009] In one embodiment, the composition of the present disclosure may be prepared by dissolving an aluminum(III) salt and a permanganate in water and adjusting the pH of the polishing solution to a desired pH.

[0010] In one embodiment, the aluminum(III) salt may be selected from aluminum(III) nitrate or aluminum(III) acetate. In a particular embodiment, the aluminum(III) salt may be aluminum(III) nitrate (Al(NO3)3).

[0011] The amount of aluminum(III) salt may be at least 0.1% by weight, or at least 0.2% by weight, or at least 0.3% by weight, or at least 0.5% by weight, or at least 0.07% by weight, or at least 0.8% by weight, or at least 1% by weight, or at least 2% by weight, or at least 3% by weight, based on the total weight of the abrasive composition. In another embodiment, the amount of aluminum(III) salt may be 20% by weight or less, or 10% by weight or less, or 5% by weight or less, or 4% by weight or less, or 2% by weight or less, or 1% by weight or less, based on the total weight of the composition. The amount of aluminum(III) salt may be at least 0.1% by weight and 5% by weight or less, at least 0.2% by weight and 2% by weight or less, or at least 0.25% by weight and 1.2% by weight or less, based on the total weight of the composition, and may be between any of the above minimum and maximum values.

[0012] In one non-limiting embodiment, the composition is total Al in the range of 1:5 to 1:50. 3+- Ion vs. Total MnO4 - It may have a molar ratio of ions. In one embodiment, Al 3+The molar ratio of ions to permanganate ions may be 1:5 or less, or 1:8 or less, or 1:10 or less, or 1:15 or less, or 1:20 or less. In another embodiment, Al 3+ The ratio of ions to permanganate ions may be at least 1:50, or at least 1:40, or at least 1:30, or at least 1:20, or at least 1:15. 3+ Ion vs. MnO4 - The molar ratio of ions can be a value between any of the minimum and maximum values ​​mentioned above, such as 1:5 to 1:50, 1:10 to 1:30, or 1:10 to 1:20.

[0013] The amount of permanganate in the abrasive composition may be at least 2.5% by weight, or at least 2.8% by weight, or at least 3.0% by weight, or at least 3.5% by weight, or at least 4.0% by weight, or at least 4.5% by weight, or at least 5.0% by weight, or at least 5.2% by weight, or at least 5.4% by weight, or at least 5.6% by weight, or at least 5.8% by weight, or at least 6.0% by weight, or at least 6.5% by weight, or at least 7.0% by weight, or at least 8% by weight, or at least 9% by weight, or at least 10% by weight. In another embodiment, the amount of permanganate may be 15% by weight or less, or 12% by weight or less, or 10% by weight or less, or 8% by weight or less, or 6% by weight or less, or 5.8% by weight or less, or 5.6% by weight or less. The amount of permanganate may be between the minimum and maximum values ​​mentioned above, at least 4.5% by weight or 8% by weight, or at least 5.0% by weight or 6% by weight, based on the total weight of the abrasive composition.

[0014] The abrasive composition may further include one or more optional additives, such as surfactants, dispersants, or chelating agents, pH buffers, rheology modifiers, corrosion inhibitors, one or more additional solvents, or any combination thereof.

[0015] In certain embodiments, the abrasive compositions of the present disclosure may essentially consist of a permanganate, an aluminum(III) nitrate, and water. Essentially consisting of means that the amount of other components or impurities contained in the abrasive composition is 0.1% by weight or less, or 0.05% by weight or less, or 0.01% by weight or less, or 0.005% by weight or less, or 0.001% by weight or less, based on the total weight of the abrasive composition.

[0016] The pH of the abrasive composition can be in the range of 1.5 to 4.5. In certain embodiments, the pH may be at least 1.8, or at least 2.0, or at least 2.2, or at least 2.5, or at least 2.7, or at least 3.0, or at least 3.2. In other embodiments, the pH of the composition may be 4.5 or less, for example, 4.3 or less, or 4.1 or less, or 4.0 or less, or 3.9 or less, or 3.8 or less, or 3.7 or less, or 3.6 or less, or 3.5 or less. The pH of the abrasive composition may be a value between any of the above minimum and maximum values, such as at least 1.5 and 4.5, at least 2.0 and 4.2, or at least 2.2 and 4.0. In certain embodiments, the pH may be at least 3.0 and 4.5, or at least 3.5 and 4.5, which has the advantage of working under less corrosive conditions.

[0017] In certain embodiments, the abrasive composition may not contain a corrosion inhibitor.

[0018] In other specific embodiments, a second oxidizing agent may be included in the abrasive composition. Non-limiting examples in this regard may be peroxides, peroxodisulfates, chlorites, perchlorates, hypochlorites, iodates, periodates, bromine, nitrites, hyponitrites, chromates, or any combination thereof.

[0019] In another embodiment, the polishing composition of the present disclosure may include polishing particles. The polishing particles are not limited to a specific material type and may include, for example, zirconia, alumina, silica, diamond, cubic boron nitride, ceria, iron oxide, titanium oxide, manganese oxide, lanthanum oxide, or any combination thereof. In a particular embodiment, the polishing particles may be selected from alumina, zirconia, manganese dioxide, ceria, silica, diamond, or iron oxide. In a particular embodiment, the polishing particles may be alumina. In another particular embodiment, the polishing particles may be zirconia.

[0020] The average size (D50) of the abrasive particles may be at least 10 nm, or at least 25 nm, or at least 50 nm, at least 80 nm, at least 100 nm, at least 130 nm, or at least 150 nm, at least 180 nm, or at least 200 nm, or at least 250 nm. In another embodiment, the average particle size may be 50 microns or less, for example, 20 microns or less, 10 microns or less, 5 microns or less, 1 micron or less, 0.8 microns or less, 0.5 microns or less, or 0.3 microns or less. The average particle size of the abrasive particles may be a value between any of the above minimum and maximum values, for example, at least 50 nm and 500 nm or less, at least 70 nm and 250 nm or less, or at least 80 nm and 200 nm or less.

[0021] In one embodiment, the amount of polishing particles can be at least 0.01 wt%, or at least 0.05 wt%, or at least 0.1 wt%, or at least 0.5 wt%, or at least 1 wt%, or at least 2 wt%, or at least 3 wt%, or at least 4 wt%, or at least 5 wt% based on the total weight of the composition. In another embodiment, the amount of polishing particles can be 50 wt% or less, for example, 40 wt% or less, or 30 wt% or less, or 20 wt% or less, or 15 wt% or less, or 10 wt% or less, or 8 wt% or less, or 5 wt% or less. The amount of polishing particles can be a value between any of the above minimum and maximum values. In a particular aspect, the amount of polishing particles can be at least 0.1 wt% and 5 wt% or less.

[0022] The present disclosure further relates to a method for polishing a substrate. The method can include providing the polishing composition of the present disclosure described above, bringing the polishing composition into direct contact with the substrate, and polishing the surface of the substrate. In one aspect, the substrate can be polished with a polishing pad, the polishing pad and the substrate can move relative to each other, and the polishing composition can contact the substrate and the polishing pad.

[0023] In one embodiment, the temperature of the polishing composition during polishing can be room temperature (20 - 25°C), or at least 30°C, or at least 40°C, or at least 45°C, or at least 50°C, or at least 55°C, or at least 60°C, or at least 65°C. In another embodiment, the temperature of the composition during polishing can be 90°C or less, or 85°C or less, or 80°C or less, or 75°C or less, or 70°C or less. The temperature of the composition during polishing can be a value within the range between any of the above minimum and maximum values.

[0024] In another particular aspect, the surface roughness of the substrate after polishing can be 5 Å or less, or 4 Å or less, or 3 Å or less, or 2.5 Å or less, or 2 Å or less.

[0025] In one embodiment, the substrate to be polished may include a ceramic material, metal, metal alloy, diamond, or polymer. In certain embodiments, the substrate may be a Group III-V compound, such as gallium nitride. In another specific embodiment, the substrate may be a Group IV-IV compound, such as silicon carbide. Non-limiting examples of polymers can be any combination such as polyacrylate, polymethacrylate, polyimide, polyolefin, polyacrylamide, polyester, polyurethane, or copolymers of their cross-polymers, such as those used in photoresists.

[0026] In one aspect, the polishing compositions and methods of the present disclosure can be adapted to polish silicon carbide substrates according to a material removal rate of at least 3.5 μm / hour, or at least 3.7 μm / hour, or at least 3.9 μm / hour, or at least 4 μm / hour, or at least 4.2 μm / hour, or at least 4.4 μm / hour, or at least 4.6 μm / hour, or at least 4.8 μm / hour, or at least 5.0 μm / hour, or at least 5.5 μm / hour, or at least 6.0 μm / hour, or at least 6.5 μm / hour, or at least 7 μm / hour, or at least 7.5 μm / hour, or at least 8 μm / hour, or at least 8.5 μm / hour, or at least 9 μm / hour. As used herein, the method for evaluating the polishing efficiency of polishing a silicon carbide substrate is carried out at room temperature and the following polishing conditions: polishing pad CMC D100, downforce 6 psi, platen speed 103 rpm, carrier speed 123 rpm, slurry flow rate 75 mL / min, polishing machine: Strasbaugh 6EC single-sided polishing tool. This test method is also described herein as the "silicon carbide polishing test".

[0027] Surprisingly, it has been discovered that the polishing compositions of the present disclosure can assist the chemical mechanical polishing process and contribute to a high material removal rate when polishing the substrate, along with a smooth outer surface of the polished substrate having a low surface roughness.

[0028] As will be further demonstrated in the following examples, it has been observed that, surprisingly, the polishing compositions of the present disclosure may be suitable for chemically mechanically polishing substrates, particularly silicon carbide-containing substrates, with a high material removal rate and excellent surface finish, without the addition of polishing particles.

[0029] Many different aspects and embodiments are possible. Some of these aspects and embodiments are described herein. After reading this specification, those skilled in the art will understand that these aspects and embodiments are illustrative only and do not limit the scope of the invention. Embodiments may follow one or more of the embodiments listed below.

[0030] Embodiment Embodiment 1. An abrasive composition comprising a permanganate, an aluminum(III) salt, and water, wherein the amount of the permanganate is at least 2.5% by weight based on the total weight of the abrasive composition. An abrasive composition in which the amount of aluminum(III) salt is at least 0.2% by weight based on the total weight of the abrasive composition, and the pH of the composition is 4.5 or less.

[0031] Embodiment 2. An abrasive composition comprising an aluminum(III) salt, at least 4.5% by weight of at least one permanganate based on the total weight of the abrasive composition, and water, wherein the pH of the abrasive composition is 4.5 or less, and the abrasive composition is configured to abrade a silicon carbide-containing substrate with an average material removal rate (MMR) of at least 2.5 μm / hour according to a silicon carbide abrasive test.

[0032] Embodiment 3. The polishing composition according to any one of Embodiments 1 or 2, wherein the aluminum(III) salt comprises aluminum nitrate, aluminum acetate, or a combination thereof.

[0033] Embodiment 4. The polishing composition according to Embodiment 3, wherein the aluminum(III) salt comprises aluminum nitrate (Al(NO3)3).

[0034] Embodiment 5. The polishing composition according to Embodiment 4, wherein the aluminum(III) salt is essentially made from aluminum nitrate.

[0035] Embodiment 6. The abrasive composition according to any one of Embodiments 1 to 5, wherein the composition essentially does not contain abrasive particles.

[0036] Embodiment 7. The polishing composition according to Embodiment 6, wherein the composition does not contain abrasive particles.

[0037] Embodiment 8. The polishing composition according to any one of Embodiments 1 to 7, wherein the permanganate comprises potassium permanganate or sodium permanganate.

[0038] Embodiment 9. The polishing composition according to Embodiment 8, wherein the permanganate comprises potassium permanganate.

[0039] Embodiment 10. The polishing composition according to any one of Embodiments 1 to 9, wherein the amount of the permanganate is at least 2.8% by weight, or at least 3.0% by weight, or at least 3.5% by weight, or at least 4.0% by weight, or at least 4.5% by weight, or at least 5.0% by weight, or at least 5.2% by weight, or at least 5.4% by weight, or at least 5.6% by weight, or at least 5.8% by weight, or at least 6.0% by weight, or at least 6.5% by weight, or at least 7.0% by weight, or at least 8% by weight, or at least 9% by weight, or at least 10% by weight.

[0040] Embodiment 11. The polishing composition according to any one of Embodiments 1 to 10, wherein the amount of the permanganate is 15% by weight or less, or 12% by weight or less, or 10% by weight or less, or 8% by weight or less, or 6% by weight or less, or 5.8% by weight or less, or 5.6% by weight or less.

[0041] Embodiment 12. The abrasive composition according to any one of Embodiments 1 to 11, wherein the amount of aluminum(III) salt is at least 0.3% by weight, or at least 0.5% by weight, or at least 0.8% by weight, or at least 1.0% by weight, or at least 1.2% by weight, or at least 1.4% by weight, or at least 1.6% by weight, or at least 1.8% by weight, or at least 2.0% by weight, based on the total weight of the composition.

[0042] Embodiment 13. The polishing composition according to any one of Embodiments 1 to 12, wherein the amount of aluminum(III) salt is 5% by weight or less, or 4% by weight or less, or 3% by weight or less, or 2.5% by weight or less, or 2.0% by weight or less, or 1.5% by weight or less.

[0043] Embodiment 14. The polishing composition according to any one of Embodiments 1 to 13, wherein the pH of the polishing composition is 4.2 or less, or 4.0 or less, or 3.8 or less, or 3.6 or less.

[0044] Embodiment 15. The polishing composition according to any one of Embodiments 1 to 14, wherein the pH of the polishing composition is at least 2.0, or at least 2.2, or at least 2.5, or at least 2.8, or at least 3.0, or at least 3.3, or at least 3.5.

[0045] Embodiment 16. The polishing composition according to any one of Embodiments 1 to 15, wherein the pH of the polishing composition is at least 3.0 and 4.5 or less, or at least 3.5 and 4.5 or less, or at least 3.5 and 4.0 or less.

[0046] Embodiment 17. The polishing composition according to any one of Embodiments 1 to 16, wherein the polishing composition further comprises polishing particles.

[0047] Embodiment 18. The polishing composition according to Embodiment 17, wherein the polishing particles include alumina, silica, ceria, or zirconia.

[0048] Embodiment 19. The abrasive composition according to any one of Embodiments 17 or 18, wherein the amount of abrasive particles is at least 0.05% by weight, or at least 0.1% by weight, or at least 0.5% by weight, or at least 1.0% by weight, or at least 2.0% by weight, based on the total weight of the composition.

[0049] Embodiment 20. The abrasive composition according to any one of Embodiments 17 to 19, wherein the amount of abrasive particles is 10% by weight or less, or 8% by weight or less, or 5% by weight or less, or 3% by weight or less, or 2% by weight or less, or 1% by weight or less, or 0.5% by weight or less, based on the total weight of the composition.

[0050] Embodiment 21. The polishing composition according to any one of Embodiments 1 to 20, wherein the composition further comprises a surfactant, or a dispersant, or a chelating agent, or a pH buffer, or a rheology modifier, or a corrosion inhibitor, or any combination thereof.

[0051] Embodiment 22. The polishing composition according to any one of Embodiments 2 to 21, wherein the composition is designed to polish a silicon carbide-containing substrate with a material removal rate of at least 3.7 μm / hour, or at least 3.9 μm / hour, or at least 4.0 μm / hour, or at least 4.2 μm / hour, or at least 4.4 μm / hour, or at least 4.6 μm / hour, or at least 4.8 μm / hour, or at least 5.0 μm / hour.

[0052] Embodiment 23. A method for polishing a substrate, comprising: providing a substrate and a polishing composition; and polishing the substrate with the composition using a polishing pad, wherein the composition comprises a permanganate, an aluminum(III) nitrate, and water, the amount of the permanganate being at least 2.5% by weight, the amount of the aluminum(III) salt being at least 0.2% by weight, and the pH of the composition being at least 3.0 and 4.5 or less.

[0053] Embodiment 24. The method according to Embodiment 23, wherein the composition essentially does not contain abrasive particles.

[0054] Embodiment 25. The method according to Embodiment 24, wherein the composition does not contain abrasive particles.

[0055] Embodiment 26. The method according to any one of Embodiments 25 to 25, wherein the substrate comprises a ceramic material, a metal, a metal alloy, diamond, a polymer, a III-V compound, or an IV-IV compound.

[0056] Embodiment 27. The method according to Embodiment 26, wherein the substrate contains silicon carbide.

[0057] Embodiment 28. The method according to any one of Embodiments 23 to 27, wherein the aluminum(III) salt comprises aluminum nitrate.

[0058] Embodiment 29. The method according to any one of Embodiments 23 to 28, wherein the permanganate comprises potassium permanganate or sodium permanganate.

[0059] Embodiment 30. The method according to Embodiment 29, wherein the permanganate comprises potassium permanganate.

[0060] Embodiment 31. The method according to any one of Embodiments 23 to 30, wherein the amount of the permanganate is at least 2.8% by weight, or at least 3.0% by weight, or at least 3.5% by weight, or at least 4.0%, or at least 4.5% by weight, or at least 5.0% by weight, or at least 5.2% by weight, or at least 5.4% by weight, or at least 5.6% by weight, or at least 5.8% by weight, or at least 6.0% by weight, or at least 6.5% by weight, or at least 7.0% by weight, or at least 8% by weight, or at least 9% by weight, or at least 10% by weight.

[0061] Embodiment 32. The method according to any one of Embodiments 23 to 31, wherein the amount of the permanganate is 15% by weight or less, or 12% by weight or less, or 10% by weight or less, or 8% by weight or less, or 6% by weight or less, or 5.8% by weight or less, or 5.6% by weight or less.

[0062] Embodiment 33. The method according to any one of Embodiments 23 to 32, wherein the amount of the aluminum(III) salt is at least 0.8% by weight, or at least 1.0% by weight, or at least 1.2% by weight, or at least 1.4% by weight, or at least 1.6% by weight, or at least 1.8% by weight, or at least 2.0% by weight, based on the total weight of the composition.

[0063] Embodiment 34. The method according to any one of Embodiments 23 to 33, wherein the amount of aluminum(III) salt is 5% by weight or less, or 4% by weight or less, or 3% by weight or less, or 2.5% by weight or less, or 2.0% by weight or less, or 1.5% by weight or less.

[0064] Embodiment 35. The method according to any one of Embodiments 23 to 34, wherein the pH of the composition is 4.2 or less, or 4.0 or less, or 3.8 or less, or 3.6 or less, or 3.6 or less.

[0065] Embodiment 36. The method according to any one of Embodiments 23 to 36, wherein the pH of the composition is at least 2.0, or at least 2.2, or at least 2.5, or at least 2.8, or at least 3.0, or at least 3.5.

[0066] Embodiment 37. The method according to any one of Embodiments 23 to 36, wherein the method is designed to polish a silicon carbide-containing substrate with a material removal rate of at least 3.5 μm / hour, or at least 4.0 μm / hour, or at least 4.5 μm / hour, or at least 5.0 μm / hour, or at least 5.5 μm / hour, or at least 6.0 μm / hour, or at least 6.5 μm / hour, or at least 7.0 μm / hour, or at least 7.5 μm / hour, or at least 8.0 μm / hour, or at least 8.5 μm / hour, or at least 9.0 μm / hour.

[0067] Embodiment 38. The method according to any one of Embodiments 23 to 37, wherein the composition further comprises abrasive particles.

[0068] Embodiment 39. The method according to Embodiment 38, wherein the abrasive particles include alumina, silica, ceria, or zirconia.

[0069] Embodiment 40. The method according to any one of Embodiments 38 to 39, wherein the amount of abrasive particles is at least 0.05% by weight, or at least 0.1% by weight, or at least 0.5% by weight, or at least 1.0% by weight, or at least 2.0% by weight, based on the total weight of the composition.

[0070] Embodiment 41. The method according to any one of Embodiments 38 to 40, wherein the amount of abrasive particles is 10% by weight or less, or 8% by weight or less, or 5% by weight or less, or 3% by weight or less, or 2% by weight or less, or 1% by weight or less, or 0.5% by weight or less, based on the total weight of the composition.

[0071] Embodiment 42. The method according to any one of Embodiments 23 to 41, wherein the composition further comprises a surfactant, or a dispersant, or a chelating agent, or a pH buffer, or a rheology modifier, or a corrosion inhibitor, or any combination thereof. [Examples]

[0072] The following non-limiting embodiments illustrate the present invention.

[0073] Example 1 The aqueous abrasive composition was prepared by dissolving potassium permanganate (KMnO4) and aluminum nitrate notahydrate in water.

[0074] Each polishing composition was evaluated according to its polishing efficiency by measuring the material removal rate (MMR) when polishing silicon carbide test wafers.

[0075] A 150 mm diameter 4H-type silicon carbide (4° off-axis) wafer was used as the silicon carbide test wafer.

[0076] The silicon carbide (SiC) wafers were polished according to the method described below. The material removal rate (MMR) was calculated from the weight loss of the SiC wafer, measured using an Ohaus Explorer Model FX324 precision scale.

[0077] Polishing method: Polishing pad CMC D100, downforce 6 psi, platen speed 103 rpm, carrier speed 123 rpm, slurry flow rate 75 mL / min, polishing machine: Strasbaugh 6EC single-sided polishing tool, room temperature.

[0078] In the preliminary experimental set, Al 3+ In the presence of ions, an enhanced increase in the silicon dioxide material removal rate (MRR) could be obtained at potassium permanganate (KMnO4) concentrations of 2.5 wt% or higher, and it was observed that the best results were obtained at KMnO4 concentrations of 4-6 wt%. The following experiment shows the relationship between polishing efficiency (MMR) and Al 3+ The focus will be on investigating the amount of ions (added in the form of aluminum nitrate nonahydrate) and the pH.

[0079] The first series of samples was prepared by varying the amount of aluminum nitrate salt. The amount of aluminum nitrate nonahydrate was increased from 0% to 3 wt%, and the amount of KMnO4 was 4 wt% for each sample (see Samples S1 - S4 and Comparative Sample C1). An overview of the polishing compositions and the resulting SiC material removal rates (MRR) is shown in Table 1. As used herein, the term "aluminum nitrate nonahydrate" also refers to Al(NO3)3 or aluminum nitrate nonahydrate, and the amounts of weight % stated refer to aluminum nitrate nonahydrate.

[0080]

Table 1

[0081] From the data summarized in Table 1, it can be seen that the highest MRR was achieved at a concentration of 1 wt% Al(NO3).

[0082] The second series of samples was designed to investigate the effect of the amount of Al(NO3)3 in the range of 1 wt% - 2 wt%, while the amount of KMnO4 was 6 wt% and the selected pH was 4.5 (see Table 2). The data also shows that in this series, the highest MRR was obtained with 1 wt% Al(NO3), while the MRR decreased at higher Al 3+ concentrations.

[0083]

Table 2

[0084] In the third series of samples (Compositions S8 - S11), the pH was varied between 2.1 - 5.5, the amount of KMnO4 was 6.0 wt%, and the amount of Al(NO3)3 was 1 wt%. An overview of the polishing results is shown in Table 3.

[0085]

Table 3

[0086] The data in Table 3 shows that the highest MRR was achieved in the pH range of 3.5–4.5, and a significant decrease in MRR was observed at pH 5.5. Surprisingly, the highest polishing efficiency was observed in the pH range of 3.5–4.5. This has the advantage of avoiding polishing under highly acidic conditions, typically below pH 2, in the field of SiC polishing. By increasing the pH value, for example, to the range of pH 3.0–4.5, susceptibility to corrosion can be reduced.

[0087] Table 4 shows comparative MRR data for abrasive compositions containing 5.5 wt% KMnO4 and 1 wt% aluminum nitrate nonahydrate, with pH varying between 3.5 and 11. The results are consistent with those in Table 3, indicating a dramatic decrease in MRR at higher pH values. At pH 11, almost no abrasive effect was achieved.

[0088] [Table 4]

[0089] Example 2 A series of polishing compositions were prepared to compare the MRR (Multiplier Risk) when using different permanganates, such as potassium permanganate (KMnO4) and sodium permanganate (NaMnO4), in combination with aluminum nitrate salts.

[0090] Table 5 shows an overview of the polishing compositions tested and the resulting material removal rates (MMR). Both KMnO4 and NaMnO4 exhibited high MMR for polishing SiC wafers, and it can be observed that the polishing speed was approximately 30% higher when using KMnO4 compared to compositions containing NaMnO4.

[0091] [Table 5]

[0092] Furthermore, comparative compositions were prepared and tested by replacing potassium permanganate with various other oxidizing agents such as hydrogen peroxide, oxone, ammonium persulfate, and potassium persulfate. A summary of the polishing compositions and polishing test results is shown in Table 6. It can be seen that the polishing compositions in which permanganate was replaced with hydrogen peroxide, oxone, ammonium persulfate, and potassium persulfate were unsuitable for silicon carbide polishing. The material removal rate of silicon carbide was zero when comparative polishing compositions C2 to C5 were used.

[0093] [Table 6]

[0094] Example 3 The abrasive compositions differ in their effect on MRR, depending on the Al 3+ Salts: Aluminum nitrate notahydrate, aluminum acetate, and aluminum sulfate were prepared for comparison. In each composition, Al 3+ The salt content was 1% by weight, the KMnO4 content was 5.5% by weight, and the pH was 3.5. It was observed that the polishing composition containing aluminum nitrate had the highest MRR (Multiplier Reaction Rate) for silicon carbide. When aluminum nitrate was substituted with aluminum acetate, the MRR for silicon carbide was approximately 20% lower. By substituting aluminum nitride with aluminum sulfate, the composition had almost no ability to polish SiC wafers.

[0095] The aforementioned specification has described the concept with reference to specific embodiments. However, those skilled in the art will understand that various modifications and changes can be made without departing from the scope of the invention as set forth in the following claims. Therefore, the specification and drawings should be considered illustrative rather than restrictive, and all such modifications are intended to fall within the scope of the invention.

Claims

1. An abrasive composition comprising aluminum (III) salt, permanganate, and water, The amount of the permanganate is at least 2.5% by weight, based on the total weight of the polishing composition. The amount of the aluminum(III) salt is at least 0.2% by weight, based on the total weight of the polishing composition. An abrasive composition having a pH of 4.5 or less.

2. An abrasive composition comprising an aluminum (III) salt, at least 2.5% by weight of at least one permanganate based on the total weight of the abrasive composition, and water, The pH of the composition is 4.5 or less. The aforementioned composition is configured to polish a silicon carbide-containing substrate with an average material removal rate (MMR) of at least 3.5 μm / hour, according to a test silicon carbide polishing test.

3. The polishing composition according to claim 1 or 2, wherein the aluminum (III) salt comprises aluminum nitrate or aluminum acetate.

4. The polishing composition according to claim 3, wherein the aluminum (III) salt essentially consists of aluminum nitrate.

5. The abrasive composition according to claim 1 or 2, wherein the composition essentially does not contain abrasive particles.

6. The polishing composition according to claim 1 or 2, wherein the permanganate comprises potassium permanganate.

7. The polishing composition according to claim 1 or 2, wherein the amount of the permanganate is at least 4% by weight based on the total weight of the polishing composition.

8. The polishing article according to claim 1 or 2, wherein the amount of the aluminum (III) salt is at least 0.5% by weight based on the total weight of the polishing composition.

9. The polishing composition according to claim 1 or 2, wherein the pH of the polishing composition is at least 3.0 and 4.5 or less.

10. The polishing composition according to claim 1 or 2, wherein the amount of aluminum(III) salt is at least 0.50% by weight based on the total weight of the polishing composition, the amount of permanganate is at least 4% by weight based on the total weight of the polishing composition, and the pH of the polishing composition is at least 3.0 and 4.5 or less.

11. A method for polishing a circuit board, To provide a substrate and a polishing composition, This includes polishing the substrate with the polishing composition using a polishing pad, A method wherein the abrasive composition comprises an aluminum (III) salt, a permanganate, and water, wherein the amount of the permanganate is at least 2.5% by weight, the amount of the aluminum (III) salt is at least 0.2% by weight, and the pH of the abrasive composition is 4.5 or less.

12. The method according to claim 11, wherein the abrasive composition essentially does not contain abrasive particles.

13. The method according to Embodiment 11 or 12, wherein the substrate comprises a ceramic material, a metal, a metal alloy, a diamond, a polymer, a III-V compound, or an IV-IV compound.

14. The method according to claim 13, wherein the substrate contains silicon carbide.

15. The method according to claim 11 or 12, wherein the pH of the abrasive composition is at least 3.0 and 4.5 or less.

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