Chemical mechanical polishing solution for stainless steel substrate and preparation method of chemical mechanical polishing solution

Abstract

The invention discloses a chemical mechanical polishing solution for a stainless steel substrate and a preparation method of the chemical mechanical polishing solution. The pH value of the polishing solution ranges from 7 to 14. The polishing solution is composed of the following components: 4 wt% to 30 wt% of silicon dioxide particles, 0.01 wt% to 1 wt% of an oxidant, 0.1 wt% to 0.5 wt% of a complexing agent, 500 ppm to 1500 ppm of an emulsifier, and 100 ppm to 1500 ppm of a foaming inhibitor. The content of the pH regulator is 0.01-0.1 wt%, and the balance is deionized water. Wherein the particle size is between 30 nm and 150 nm. The stainless steel polishing solution is prepared by the following steps: cleaning the surface of stainless steel at room temperature, taking a certain amount of deionized water, adding the required additive, fully dissolving, adding a certain amount of silica sol, and fully stirring again. The gelation phenomenon caused by directly adding the additive into the silica sol is prevented. The alkaline polishing solution is good in suspension property after being placed for a long time, and the phenomena of crystallization, layering and the like are avoided. And meanwhile, the polishing rate is guaranteed, and the defects such as surface orange peel and rime fog can be avoided. The requirements of the stainless steel substrate are met.

Description

Technical Field

[0001] The invention relates to the technical field of polishing liquid, in particular to a chemical mechanical polishing liquid for a stainless steel substrate and a preparation method thereof. Background Art

[0002] Stainless steel is a very important type of steel. Due to its corrosion resistance, wear resistance, high temperature resistance and good machinability, it is widely used in flexible large-size display substrates, mobile phone frames, camera metal rings, brand logos and interior decoration. As a flexible large-size display substrate material, the presence of depressions and peaks on the surface will lead to the appearance of "black spots" on the device. Therefore, it is necessary to continuously improve the surface quality.

[0003] However, the surface finish obtained by traditional processing technology may not meet strict requirements. Therefore, it is necessary to develop ultra-precision processing technology to further improve the surface quality. Chemical mechanical polishing technology (CMP) is one of the key technologies in semiconductor manufacturing. It is specially used to prepare global planarized surfaces with extremely low roughness by combining the friction effect of polishing liquid particles with the corrosion effect of additives. CMP has been widely used to manufacture stainless steel surfaces with nanoscale surface finish, making large-scale, high-quality stainless steel substrate processing possible. The most important component in the chemical mechanical polishing process is the polishing liquid. The composition of the polishing liquid affects the surface quality of the stainless steel material.

[0004] At present, the commonly used stainless steel polishing liquids are mainly alumina polishing liquid and silica sol polishing liquid. Although the alumina polishing liquid has a high removal rate, it has serious surface defects. The commonly used silica sol polishing liquid has a mature production process and low cost, but the removal rate is low. How to improve the removal rate while maintaining a long storage time and excellent surface quality has become a problem that needs to be solved at present. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the above technical defects and provide a chemical mechanical polishing liquid for stainless steel substrates, which is mainly used for stainless steel substrates. The use of the present invention can obtain a stainless steel substrate material with a high polishing rate and good surface effect.

[0006] In order to solve the above problems, the technical solution of the present invention is: a chemical mechanical polishing liquid for a stainless steel substrate, comprising at least the following components: 4wt% to 30wt% of silicon dioxide particles, 0.01wt% to 1wt% of an oxidant, 0.1wt% to 0.5wt% of a complexing agent, 500ppm to 1500ppm of an emulsifier, 100ppm to 1500ppm of a foaming inhibitor, 0.01wt% to 0.1wt% of a pH adjuster and an appropriate amount of deionized water.

[0007] Furthermore, the diameter of the silicon dioxide particles is 30 nm to 150 nm, and preferably the diameter of the silicon dioxide polishing particles is 90 nm to 120 nm.

[0008] Furthermore, the pH adjuster is selected from one or more of the group consisting of potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide, hydrochloric acid, glycine, and citric acid, and the pH value range is 7.5-14.

[0009] Furthermore, the oxidant is selected from one or more of the group consisting of potassium persulfate, aluminum nitrate and sodium hypochlorite.

[0010] Furthermore, the complexing agent is selected from one or more of the group consisting of pentasodium diethylenetriaminepentaacetate, tetrasodium glutamate diacetate, trisodium aminotriacetate, and trisodium hydroxyethylethylenediaminetriacetate.

[0011] Furthermore, the emulsifier is selected from one or more of the group consisting of isomeric tridecanol polyoxyethylene ether, 4-tert-octylphenol polyoxyethylene ether, C8-10 alcohol polyoxyethylene ether, polyethylene glycol polyoxyethylene ether, alkylphenol polyoxyethylene ether, multi-branched C10 alcohol polyoxyethylene ether, linear C12-15 alcohol polyoxyethylene ether, sodium lauryl ether sulfate, sodium lauryl ether sulfonate succinic acid monoester disodium salt, isooctyl alcohol polyoxyethylene ether phosphate, and sodium dodecyl diphenyl ether disulfonate.

[0012] Furthermore, the foaming inhibitor is selected from one or more of the group consisting of silicone defoamers and polydimethylsiloxane.

[0013] A method for preparing a chemical mechanical polishing liquid for a stainless steel substrate,

[0014] Step 1: Use 800-grit sandpaper to grind the stainless steel for 1 minute, and then clean the surface with deionized water;

[0015] Step 2: Add the above-mentioned additives into deionized water and fully dissolve;

[0016] Step 3: Add the mixture obtained in step 2 to a certain amount of silica sol and stir evenly;

[0017] Step 4: Adjust the pH of the above mixture, and the resulting mixed solution is the stainless steel polishing liquid.

[0018] The advantages of the present invention compared with the prior art are:

[0019] In the present invention, due to the selection of silica sol with a particle size of 30-150 nanometers and a concentration of 4wt%-30wt%, the stainless steel has good mechanical force during the polishing process, and can achieve good polishing removal efficiency of the stainless steel surface. Adding 0.01wt%-1wt% oxidant accelerates the oxidation rate of the stainless steel surface and can form an oxide film, which can protect the surface and improve the smoothness and flatness of the stainless steel surface. Adding 0.1wt%-0.5wt% complexing agent to the system, the complexing agent with strong complexing ability can be used as a catalyst for the oxidation of the stainless steel substrate, so that more metal cations are generated in the fluid, which is conducive to the dissolution of iron. The complexing agent with large steric hindrance and high electrostatic repulsion (high charge density) can form a stable boundary layer on the substrate surface, and is conducive to the nanoparticles formed during the dispersion process, thereby improving the polishing removal efficiency of the stainless steel and improving the surface quality. In addition, the polishing rate reaches more than 5μm / h, has good stability, can be kept for more than 12 months at room temperature, avoids sol gel, and is convenient for chemical mechanical polishing. In addition, the present invention does not contain hydrogen peroxide, has a long service life, and relatively saves costs. DETAILED DESCRIPTION

[0020] In order to make the contents of the present invention more clearly understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention.

[0021] Examples 1 to 3: Use 800-mesh sandpaper to grind stainless steel for 1 minute, and use deionized water to clean the surface; add the required amount of oxidant, complexing agent, emulsifier, and foaming inhibitor to deionized water for dispersion and dilution, add a certain amount of silica sol, adjust the pH value and stir evenly. After washing with water, the sample is placed in a polishing liquid for polishing, washed with water, cleaned with anhydrous ethanol and dried to obtain a polished stainless steel workpiece.

[0022] The total amount of each of Examples 1 to 3 and Comparative Examples 1 to 2 prepared by this method is 50 kg, and the specific proportions are shown in Table 1.

[0023] Table 1 Components and dosage of chemical mechanical polishing liquid.

[0024] Example 1, polishing particle size and concentration, oxidant content and dosage, complexing agent content and dosage, emulsifier content and dosage, foaming inhibitor content and dosage, pH adjuster and pH value, removal rate, surface quality.

[0025]

[0026]

[0027] The polishing liquid samples prepared in Examples 1-3 and Comparative Examples 1 and 2 were placed at room temperature to check their properties.

[0028] Example 1 No gel after one and a half years Example 2 Partial gel after one year Example 3 No gel after one year Example 4 No gel after one year Comparative Example 1 No gel after one year Comparative Example 2 Stratification after one and a half years

[0029] The above polishing liquid was used for chemical mechanical polishing of stainless steel. The polishing conditions are shown in Table 2.

[0030] Table 2 Polishing conditions

[0031]

[0032]

[0033] The present invention and its implementation methods are described above, and such description is not restrictive, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design structures and embodiments similar to the technical solution without creativity, which should all fall within the protection scope of the present invention.

Claims

1. A chemical mechanical polishing liquid for a stainless steel substrate, characterized in that: The invention comprises at least the following ingredients: 4wt% to 30wt% of silicon dioxide particles, 0.01wt% to 1wt% of an oxidizing agent, 0.1wt% to 0.5wt% of a complexing agent, 500ppm to 1500ppm of an emulsifier, 100ppm to 1500ppm of a foaming inhibitor, 0.01wt% to 0.1wt% of a pH adjusting agent and an appropriate amount of deionized water.

2. The chemical mechanical polishing liquid for stainless steel substrate according to claim 1, characterized in that: The diameter of the silicon dioxide particles is 30 nm to 150 nm, and preferably the diameter of the silicon dioxide polishing particles is 90 nm to 120 nm.

3. The chemical mechanical polishing liquid for stainless steel substrate according to claim 1, characterized in that: The pH adjuster is selected from one or more of the group consisting of potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide, hydrochloric acid, glycine, and citric acid, and the pH value range is 7.5-14.

4. The chemical mechanical polishing liquid for stainless steel substrate according to claim 1, characterized in that: The oxidant is selected from one or more of the group consisting of potassium persulfate, aluminum nitrate, and sodium hypochlorite.

5. The chemical mechanical polishing liquid for stainless steel substrate according to claim 1, characterized in that: The complexing agent is one or more selected from the group consisting of pentasodium diethylenetriaminepentaacetate, tetrasodium glutamate diacetate, trisodium aminotriacetate, and trisodium hydroxyethylethylenediaminetriacetate.

6. The chemical mechanical polishing liquid for stainless steel substrate according to claim 1, characterized in that: The emulsifier is selected from one or more of the group consisting of isomeric tridecanol polyoxyethylene ether, tert-octylphenol polyoxyethylene ether, C8-10 alcohol polyoxyethylene ether, polyethylene glycol polyoxyethylene ether, alkylphenol polyoxyethylene ether, multi-branched C10 alcohol polyoxyethylene ether, linear C12-15 alcohol polyoxyethylene ether, sodium lauryl ether sulfate, sodium lauryl ether sulfonate succinic acid monoester disodium salt, isooctyl alcohol polyoxyethylene ether phosphate, and sodium dodecyl diphenyl ether disulfonate.

7. The chemical mechanical polishing liquid for stainless steel substrate according to claim 1, characterized in that: The foaming inhibitor is selected from one or more of the group consisting of silicone defoaming agents and polydimethylsiloxane.

8. A method for preparing a chemical mechanical polishing liquid for a stainless steel substrate according to claims 1-6, characterized in that: Step 1: Use 800-grit sandpaper to grind the stainless steel for 1 minute, and then clean the surface with deionized water; Step 2: Add the above-mentioned additives into deionized water and fully dissolve; Step 3: Add the mixture obtained in step 2 to a certain amount of silica sol and stir evenly; Step 4: Adjust the pH of the above mixture, and the resulting mixed solution is the stainless steel polishing liquid.

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