Polishing slurry composition
By adding inhibitors and other regulators to the polishing slurry composition, the butterfly defect problem caused by the high polishing rate of cerium oxide is solved, and the balance between high polishing rate and low defect is achieved, and the yield and production efficiency of the product are improved.
Patent Information
- Application Number
- CN202311275713.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-28
- Publication Date
- 2025-03-28
AI Technical Summary
During the chemical mechanical polishing (CMP), the high polishing rate of cerium oxide can easily lead to butterfly defects on the wafer surface, reducing product yields, and reducing polishing efficiency will increase production costs, making it difficult to achieve a balance between high polishing rate and low defects.
A polishing slurry composition is provided, including water, cerium oxide, inhibitors, additives, pH adjusters and anionic surfactants, through which the combination of these components can reduce the occurrence of depression and erosion while maintaining a high polishing rate.
It realizes maintaining a high polishing rate during the CMP process, improving the selection ratio between silicon oxide and silicon nitride, and effectively reducing the occurrence of depression and erosion, improving the yield of the product and reducing production costs.
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Figure CN119709019A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a polishing slurry composition. Background Art
[0002] Chemical mechanical polishing (CMP) is a combination of chemical action, mechanical action, and the combination of these two actions. It usually consists of a grinding table with a polishing pad and a grinding head for carrying a wafer. The grinding head fixes the wafer and then presses the front side of the wafer onto the polishing pad. When chemical mechanical polishing is performed, the grinding head moves linearly on the polishing pad or rotates in the same direction as the grinding table. At the same time, a slurry containing abrasive particles is dripped onto the polishing pad and spreads flat on the polishing pad due to centrifugal action. The wafer surface is globally flattened under the dual action of mechanical and chemical. In order to protect the quality of the patterned polysilicon film in the shallow trench isolation (STI) process, it is necessary to increase the polishing rate of the insulating film layer and reduce the polishing rate of the polysilicon film layer, which is the so-called selective polishing characteristic. In particular, even if over-polishing is performed in the cell type pattern, the loss of the polysilicon film should be reduced.
[0003] Cerium oxide has a long history of being used as a polishing abrasive for precision glass polishing and polishing of silicon dioxide dielectric layers in ultra-large-scale integrated circuits. Cerium oxide abrasives can react chemically with silicon oxide. Under the same conditions, the polishing rate of cerium oxide is about three times that of silicon oxide, especially in neutral polishing liquids. It maintains a high removal rate and has a high polishing selectivity between silicon oxide and silicon nitride. It has been widely used in chemical mechanical polishing of silicon dioxide. However, during the CMP process, excessively high polishing rates can easily produce butterfly defects on the wafer surface, reducing product yield. If the polishing rate is not suppressed, the butterfly defects cannot be completely eliminated; but reducing polishing efficiency also increases production costs. Therefore, minimizing the occurrence of pitting and erosion defects during the CMP process while obtaining a higher polishing rate is an urgent problem to be solved in the development of polishing slurry compositions. Summary of the invention
[0004] In view of the above problems existing in the prior art, the present invention provides a polishing slurry composition. The polishing slurry composition of the present invention satisfies one or more of the following effects and advantages: maintaining a high polishing rate, improving the selectivity, and reducing the occurrence of dishing and erosion.
[0005] The present invention provides a polishing slurry composition, which is prepared by the following raw materials, wherein the raw materials include the following components by mass fraction: water, 0.1%-10% cerium oxide, 0.1-5% inhibitor, 0.01-5% additive, 0.01-2% pH regulator and 50-500ppm anionic surfactant; the mass fraction of each component is the mass fraction of the component in the polishing slurry composition; the sum of the mass fractions of each component is 100%;
[0006] The additive is a compound as shown in Formula I:
[0007]
[0008] Where n is an integer greater than 1, R 2 is substituted or unsubstituted C1-C 30 Alkylene, substituted or unsubstituted C2-C 30 Alkenylene, substituted or unsubstituted C3-C 30 Cycloalkylene, substituted or unsubstituted C6-C 14 Arylene or substituted or unsubstituted C2-C 30 Alkyne; the substituent is hydroxyl, carboxyl or C1-C6 alkyl;
[0009] R 1 , R 3 and R 4 are independently hydrogen, carboxyl, substituted or unsubstituted C1-C 30 Alkyl, substituted or unsubstituted C1-C 30 Alkoxy, or, substituted or unsubstituted C6-C 14 Aryl; the substituents are each independently selected from the following groups: hydroxyl, carboxyl or C1-C6 alkyl.
[0010] In certain preferred embodiments of the present invention, certain raw materials and mass fractions in the polishing slurry composition are defined as follows, and the raw materials and mass fractions not mentioned are the same as those described in any embodiment of the present invention (referred to as "in some embodiments"),
[0011] In some embodiments, the pH value of the polishing slurry composition is a conventional pH value in the art, preferably 4-7, more preferably 6.
[0012] In some embodiments, in Formula I, n may be an integer from 1 to 500; preferably an integer from 50 to 350; for example 200.
[0013] In some embodiments, the weight average molecular weight of the compound of Formula I may be 1000-1000000; preferably 2000-500000; more preferably 5000-100000; for example 10000-25000.
[0014] In some embodiments, R 2 wherein the substituted or unsubstituted C1-C 30 The C1-C 30 The alkylene group may be a C1-C6 alkylene group, more preferably a methylene group, -CH2CH2-, -CH2CH2CH2- or -CH(CH3)2-; for example, a methylene group.
[0015] In some embodiments, R 2 wherein the substituted or unsubstituted C6-C 14 C6-C in arylene 14 The arylene group may be a phenylene group or a naphthylene group, preferably a phenylene group, for example
[0016] In some embodiments, R 3 wherein the substituted or unsubstituted C1-C 30 C1-C 30 The alkyl group may be a C1-C6 alkyl group, more preferably a methyl group, an ethyl group, a n-propyl group or an isopropyl group; for example, a methyl group.
[0017] In some embodiments, the R 1 For hydrogen.
[0018] In some embodiments, the R 2 is an unsubstituted C1-C6 alkylene or an unsubstituted C6-C 14 Arylene; preferably methylene or
[0019] In some embodiments, the R 3 It is a carboxyl group or a C1-C6 alkyl group; preferably a carboxyl group or a methyl group.
[0020] In some embodiments, the R 4 For hydrogen.
[0021] In some embodiments, the compound as shown in Formula I is
[0022] In some embodiments, the inhibitor is a conventional inhibitor in the art, which may be an amino acid, and the amino acid is preferably one or more of glycine, alanine, valine, leucine, isoleucine, methionine (methionine), proline, tryptophan, serine, tyrosine, cysteine, phenylalanine, asparagine, glutamine, threonine, aspartic acid, glutamic acid, lysine, arginine and histidine, such as alanine.
[0023] In some embodiments, the pH adjuster is a conventional pH adjuster in the art; preferably an inorganic base or an organic base; the inorganic base is preferably aqueous ammonia; the organic base is preferably a quaternary ammonium base, and the quaternary ammonium base is preferably choline.
[0024] In some embodiments, the anionic surfactant is a conventional anionic surfactant in the art; it may be a carboxylic acid derivative and / or a sulfonate, wherein the carboxylic acid derivative is preferably one or more of carboxylates, carboxylates and salts and fatty alcohol polyether-n carboxylate salts; the sulfonate is preferably one or more of alkyl sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates and succinate sulfonates; the alkylbenzene sulfonate is more preferably sodium dodecylbenzene sulfonate.
[0025] In some embodiments, the water is conventional in the art, and the water is pure water; the water is preferably selected from one or more of deionized water, distilled water and ultrapure water, such as deionized water.
[0026] In some embodiments, the mass fraction of the cerium oxide is preferably 0.1%-10%, for example 3%.
[0027] In some embodiments, the cerium oxide may be cerium oxide abrasive particles; the shape of the abrasive particles is preferably spherical or nearly spherical.
[0028] In some embodiments, the average particle size of the cerium oxide is 50-300 nanometers, preferably 80-180 nanometers, such as 150 nanometers.
[0029] In some embodiments, the mass fraction of the inhibitor is preferably 0.1% to 5%, more preferably 0.5% to 3%, for example 1.5% or 2%.
[0030] In some embodiments, the mass fraction of the additive is preferably 0.01% to 5%, more preferably 0.5% to 1.5%, for example 0.8%.
[0031] In some embodiments, the mass fraction of the pH adjuster is preferably 0.01-2%; more preferably 0.2%-1%; for example 0.5% or 0.6%.
[0032] In some embodiments, the concentration of the anionic surfactant is preferably 50-500 ppm, more preferably 100-200 ppm, such as 150 ppm.
[0033] In some embodiments, the polishing slurry composition is composed of the following components in mass fractions: 0.1%-10% cerium oxide, 0.1-5% inhibitor, 0.01-5% additive, 0.01-2% pH adjuster, 50-500ppm anionic surfactant and water, with water making up the balance, and the sum of the mass fractions of each component is 100%.
[0034] In some embodiments, the polishing slurry composition is prepared from the following raw materials: deionized water, cerium oxide, alanine, additives, pH regulator and sodium dodecylbenzene sulfonate; the additive is The pH regulator is choline or ammonia water.
[0035] In some embodiments, the raw materials of the polishing slurry composition are composed of any of the following formulas:
[0036] Solution 1: 3% cerium oxide, 1.5% alanine, 0.8% 0.5% ammonia water, 150ppm sodium dodecylbenzene sulfonate, and the rest water to make up to 100%;
[0037] Solution 2: 3% cerium oxide, 2% alanine, 0.8% 0.5% ammonia water, 150ppm sodium dodecylbenzene sulfonate, and the rest water to make up to 100%;
[0038] Solution 3: 3% cerium oxide, 1.5% alanine, 0.8% 0.6% choline, 150ppm sodium dodecylbenzene sulfonate, and the balance of water to make up to 100%;
[0039] Solution 4: 3% cerium oxide, 2% alanine, 0.8% 0.6% choline, 150ppm sodium dodecylbenzene sulfonate, and the balance of water to make up to 100%;
[0040] Solution 5: 3% cerium oxide, 1.5% alanine, 0.8% 0.5% ammonia water, 150ppm sodium dodecylbenzene sulfonate, and the rest water to make up to 100%;
[0041] Solution 6: 3% cerium oxide, 2% alanine, 0.8% 0.5% ammonia water, 150ppm sodium dodecylbenzene sulfonate, and the rest water to make up to 100%;
[0042] Solution 7: 3% cerium oxide, 1.5% alanine, 0.8% 0.6% choline, 150ppm sodium dodecylbenzene sulfonate, and the balance of water to make up to 100%;
[0043] Solution 8: 3% cerium oxide, 2% alanine, 0.8% 0.6% choline, 150 ppm sodium dodecylbenzene sulfonate, and the balance of water to make up to 100%.
[0044] The present invention also provides a method for preparing the polishing slurry composition, which comprises the following steps: mixing the raw materials mentioned above.
[0045] In some embodiments, in the preparation method, the mixing is preferably adding the solid in the raw material into the liquid and stirring evenly.
[0046] In some embodiments, in the preparation method, the mixing temperature is preferably room temperature.
[0047] The present invention also provides an application of the polishing slurry composition in a polishing process of a semiconductor element.
[0048] In some embodiments, the semiconductor element is preferably a silicon wafer for polishing of a silicon dioxide dielectric layer.
[0049] In some embodiments, the polishing process is preferably a shallow trench isolation (Shallow Trench Isolation: STI) process.
[0050] In the present invention, "room temperature" refers to 10-30°C.
[0051] Without violating the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.
[0052] The reagents and raw materials used in the present invention are commercially available.
[0053] The positive improvement effect of the present invention is that the polishing slurry composition of the present invention satisfies one or more of the following advantages: it can maintain a higher polishing rate, improve the selectivity of silicon oxide to silicon nitride, and reduce the occurrence of dishing and erosion. DETAILED DESCRIPTION
[0054] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.
[0055] 1. Preparation Examples 1-8 and Comparative Examples 1-2:
[0056] Preparation of polishing slurry composition
[0057] Under mechanical stirring conditions, cerium oxide particles were added to deionized water; stirring was continued, and the raw materials of each component in Table 1 were mixed in turn according to the mass fractions in Table 2. Stirring was performed at room temperature for 2 hours. The cerium oxide particles and other components were fully mixed and evenly dispersed in the solution.
[0058] Table 1: Types of components in each example
[0059]
[0060]
[0061] No additives were added in the comparative example.
[0062] Table 2: Content of each raw material component in the polishing liquid of the embodiment
[0063]
[0064] The "remainder" in the table is 100% minus the mass percentage of other components in each example.
[0065] 2. Effect Embodiment
[0066] Polishing: The polishing device is AP-300 (CTS), the polishing pad used is IC1000, the polishing time is 60s, the platen speed is 110rpm, the spindle speed is 108rpm, the chip pressure is 3.5psi, the slurry flow rate is 200ml / min, the chips are PE-TEOS (thickness 6KA), silicon nitride chips (thickness 6KA), and patterned chips (15KA).
[0067] Test steps:
[0068] The performance tests of the polishing liquids of Examples 1-8 and Comparative Examples 1-2 are shown in Table 3. The specific test methods are as follows:
[0069] 1. Silicon oxide film polishing rate (RR)
[0070] Measured using Filmetrics F54 film thickness meter
[0071] 2. Silicon nitride film polishing rate
[0072] Measured using Filmetrics F54 film thickness meter
[0073] 3. Choose the ratio
[0074] Silicon oxide film RR / silicon nitride film RR
[0075] 4. Dishing amount of the groove in the 100μm / 100μm area
[0076] The stylus step profiler (model P16 manufactured by KLA-tencor) was used to measure
[0077] Table 3: Effects of polishing liquid in the examples
[0078]
[0079]
[0080] According to the above embodiments, the present invention can inhibit the etching speed to a certain extent by adding additives to the polishing liquid, reduce the polishing rate of the silicon nitride film more, and thus improve the selectivity; the amount of butterfly depression is low; when no additives are added, the polishing rates of silicon oxide and silicon nitride are both high, the selectivity of silicon oxide to silicon nitride is about 12, and the amount of butterfly depression (Dishing) is 1289A.
Claims
1. A polishing slurry composition, characterized in that: The polishing slurry is prepared by the following raw materials, which include the following components by mass fraction: water, 0.1%-10% cerium oxide, 0.1-5% inhibitor, 0.01-5% additive, 0.01-2% pH regulator and 50-500ppm anionic surfactant; the mass fraction of each component is the mass fraction of the component in the polishing slurry composition; the sum of the mass fractions of each component is 100%; The additive is a compound as shown in Formula I: Where n is an integer greater than 1, R 2 is substituted or unsubstituted C1-C 30 Alkylene, substituted or unsubstituted C2-C 30 Alkenylene, substituted or unsubstituted C3-C 30 Cycloalkylene, substituted or unsubstituted C6-C 14 Arylene or substituted or unsubstituted C2-C 30 Alkyne; the substituent is hydroxyl, carboxyl or C1-C6 alkyl; R 1 , R 3 and R 4 are independently hydrogen, carboxyl, substituted or unsubstituted C1-C 30 Alkyl, substituted or unsubstituted C1-C 30 Alkoxy, or, substituted or unsubstituted C6-C 14 Aryl; the substituents are each independently selected from the following groups: hydroxyl, carboxyl or C1-C6 alkyl.
2. The polishing slurry composition according to claim 1, characterized in that It satisfies one or both of the following conditions: (1) In Formula I, n is an integer from 1 to 500; preferably an integer from 50 to 350; for example, 200; and (2) The weight average molecular weight of the compound of formula I is 1,000-1,000,000; preferably 2,000-500,000; more preferably 5,000-100,000; for example 10,000-25,000.
3. The polishing slurry composition according to claim 1, characterized in that It meets one or more of the following conditions: (1)R 2 wherein the substituted or unsubstituted C1-C 30 The C1-C 30 Alkylene is C1-C6 alkylene, more preferably methylene, -CH2CH2-, -CH2CH2CH2- or -CH(CH3)2-; for example, methylene; (2)R 2 wherein the substituted or unsubstituted C6-C 14 C6-C in arylene 14 Arylene is phenylene or naphthylene, preferably phenylene, for example and (3)R 3 wherein the substituted or unsubstituted C1-C 30 C1-C 30 The alkyl group is a C1-C6 alkyl group, more preferably a methyl group, an ethyl group, a n-propyl group or an isopropyl group; for example, a methyl group.
4. The polishing slurry composition according to claim 1, characterized in that It meets one or more of the following conditions: (1) R 1 is hydrogen; (2) R 2 is an unsubstituted C1-C6 alkylene or an unsubstituted C6-C 14 Arylene; preferably methylene or (3) R 3 is carboxyl or C1-C6 alkyl; preferably carboxyl or methyl; and (4) R 4 For hydrogen.
5. The polishing slurry composition according to claim 4, characterized in that The compound shown in formula I is 6. The polishing slurry composition according to claim 1, wherein It meets one or more of the following conditions: (1) The pH value of the polishing slurry composition is a conventional pH value in the art, preferably 4-7, more preferably 6; (2) The inhibitor amino acid, wherein the amino acid is preferably one or more of glycine, alanine, valine, leucine, isoleucine, methionine (methionine), proline, tryptophan, serine, tyrosine, cysteine, phenylalanine, asparagine, glutamine, threonine, aspartic acid, glutamic acid, lysine, arginine and histidine, such as alanine; (3) The pH adjusting agent is an inorganic base or an organic base; the inorganic base is preferably ammonia water; the organic base is preferably a quaternary ammonium base, and the quaternary ammonium base is preferably choline; (4) The anionic surfactant is a carboxylic acid derivative and / or a sulfonate, wherein the carboxylic acid derivative is preferably one or more of carboxylates, carboxylates and salts and fatty alcohol polyether-n carboxylate salts; the sulfonate is preferably one or more of alkyl sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates and succinate sulfonates; the alkylbenzene sulfonate is more preferably sodium dodecylbenzene sulfonate; and (5) The water is pure water; the water is preferably selected from one or more of deionized water, distilled water and ultrapure water, such as deionized water.
7. The polishing slurry composition according to any one of claims 1 to 6, characterized in that It meets one or more of the following conditions: (1) The mass fraction of the cerium oxide is 0.1%-10%, for example 3%; (2) The cerium oxide is cerium oxide abrasive particles; the shape of the abrasive particles is preferably spherical or nearly spherical; (3) The average particle size of the cerium oxide is 50-300 nanometers, preferably 80-180 nanometers, for example 150 nanometers; (4) The mass fraction of the inhibitor is 0.1% to 5%, preferably 0.5% to 3%, for example 1.5% or 2%; (5) The mass fraction of the additive is 0.01% to 5%, preferably 0.5% to 1.5%, for example 0.8%; (6) The mass fraction of the pH adjuster is 0.01 to 2%, preferably 0.2 to 1%, for example 0.5 or 0.6%; and (7) The concentration of the anionic surfactant is 50-500 ppm, preferably 100-200 ppm, for example 150 ppm.
8. The polishing slurry composition according to claim 7, characterized in that The polishing slurry composition is composed of the following components in mass fraction: 0.1%-10% cerium oxide, 0.1-5% inhibitor, 0.01-5% additive, 0.01-2% pH regulator, 50-500ppm anionic surfactant and water, with water making up the balance, and the sum of the mass fractions of each component is 100%.
9. The polishing slurry composition according to claim 1, wherein The polishing slurry composition is prepared from the following raw materials: deionized water, cerium oxide, alanine, additives, pH regulator and sodium dodecylbenzene sulfonate; the additive is The pH regulator is choline or ammonia water.
10. The polishing slurry composition according to any one of claims 1 to 6, characterized in that The raw materials of the polishing slurry composition are composed of any of the following formulas: Solution 1: 3% cerium oxide, 1.5% alanine, 0.8% 0.5% ammonia water, 150ppm sodium dodecylbenzene sulfonate, and the rest water to make up to 100%; Solution 2: 3% cerium oxide, 2% alanine, 0.8% 0.5% ammonia water, 150ppm sodium dodecylbenzene sulfonate, and the rest water to make up to 100%; Solution 3: 3% cerium oxide, 1.5% alanine, 0.8% 0.6% choline, 150ppm sodium dodecylbenzene sulfonate, and the balance of water to make up to 100%; Solution 4: 3% cerium oxide, 2% alanine, 0.8% 0.6% choline, 150ppm sodium dodecylbenzene sulfonate, and the balance of water to make up to 100%; Solution 5: 3% cerium oxide, 1.5% alanine, 0.8% 0.5% ammonia water, 150ppm sodium dodecylbenzene sulfonate, and the rest water to make up to 100%; Solution 6: 3% cerium oxide, 2% alanine, 0.8% 0.5% ammonia water, 150ppm sodium dodecylbenzene sulfonate, and the rest water to make up to 100%; Solution 7: 3% cerium oxide, 1.5% alanine, 0.8% 0.6% choline, 150ppm sodium dodecylbenzene sulfonate, and the balance of water to make up to 100%; Solution 8: 3% cerium oxide, 2% alanine, 0.8% 0.6% choline, 150 ppm sodium dodecylbenzene sulfonate, and the balance of water to make up to 100%.