Cu-ITO etching solution and preparation method thereof

Abstract

The invention belongs to the technical field of etching solutions, and particularly discloses a Cu-ITO etching solution which comprises the following components in percentage by mass: 8-18% of hydrogen peroxide, 3-6% of a sulfonic acid derivative, 0.5-1.5% of an organic weak oxidant, 0.1-2% of a corrosion inhibitor, 0.05-1% of a hydrogen peroxide stabilizer, 1-3% of a surfactant and the balance of water. The invention provides a Cu-ITO etching solution which is composed of hydrogen peroxide, a sulfonic acid derivative, an organic weak oxidant, a corrosion inhibitor, a hydrogen peroxide stabilizer and a surfactant, all the components interact with one another, so that the etching solution can etch a Cu-ITO substrate in one step, and the Cu-ITO etching solution has the excellent characteristics of long service life and stable etching performance, and is green, environmentally friendly and small in pollution.

Description

Technical Field

[0001] The present invention belongs to the technical field of etching solutions, and particularly relates to a Cu-ITO etching solution and a preparation method thereof. Background Art

[0002] In liquid crystal displays, many gates of the array are composed of a substrate ITO material and a copper layer deposited on its upper surface. Since different etching solutions are required for the copper layer and the ITO layer, two Mask processes are carried out for exposure, development, and etching. First, the copper layer is etched and then the ITO layer is etched. Not only two etching solutions are needed, but also processes such as removal of the pre-etching solution, cleaning of the etching interface, and addition of the post-etching solution need to be added. With many Mask processes, the process cycle is long and the process cost is high. If the multi-layer film of the copper layer and the ITO layer can be etched together, the production efficiency can be greatly improved and the production cost can be effectively reduced.

[0003] Currently, KR1020220119564A discloses an etching solution composition and an etching method for a copper-based metal layer and a metal oxide layer. Based on the total weight of the etching agent composition, 5-25% by weight of hydrogen peroxide; 0.01-1% by weight of a fluorinated compound; 0.1-5% by weight of an azole compound; 0.1-5% by weight of a water-soluble compound containing nitrogen and a carboxyl group in one molecule; 0.1-5% by weight of a sulfonic acid compound; 0.01-5% by weight of a polyol-based surfactant; the balance is water. This etching solution formulation can etch the copper layer and the ITO layer in one step. The formulation includes hydrogen fluoride and nitric acid. During the etching process, hydrogen fluoride can effectively control the etching rates of Cu and ITO, achieving fine pattern transfer. However, since hydrogen fluoride is easily dissociated into fluoride ions in water, fluoride ions accumulate in the etching waste liquid, which not only increases the treatment difficulty and cost of the waste liquid, but also may cause long-term pollution to water bodies and the ecological system. Nitric acid has strong oxidizing properties and volatility, which can accelerate the etching reaction and increase the etching rate. However, as nitric acid volatilizes, the pH value and composition ratio of the etching solution change, shortening the service life of the etching solution and resulting in a decrease in etching stability, making it impossible to etch the ITO layer. Summary of the Invention

[0004] The purpose of the present invention is to provide a Cu-ITO etching solution to solve the problems such as the reduced service life of the existing etching solution and insufficient stability of etching performance.

[0005] To achieve the above technical objectives and reach the above technical effects, the present invention is realized through the following technical solutions:

[0006] In a first aspect, the present invention provides a Cu-ITO etching solution, which comprises the following components by mass percentage: 8-18% of hydrogen peroxide, 3-6% of sulfonic acid derivative, 0.5-1.5% of organic weak oxidant, 0.1-2% of corrosion inhibitor, 0.05-1% of hydrogen peroxide stabilizer, 1-3% of surfactant, and the balance is water.

[0007] Further, a Cu-ITO etching solution comprises the following components by mass percentage: 12-16% of hydrogen peroxide, 4.5-5.5% of sulfonic acid derivative, 0.75-1.25% of organic weak oxidant, 0.5-1.5% of corrosion inhibitor, 0.1-0.5% of hydrogen peroxide stabilizer, 1.5-2.5% of surfactant, and the balance is water.

[0008] Further, the sulfonic acid derivative is 4,4'-((4-sulfophenyl)azanediyl)bis(methylene)dibenzoic acid.

[0009] Still further, the chemical structure of the 4,4'-((4-sulfophenyl)azanediyl)bis(methylene)dibenzoic acid is shown in formula (Ⅰ):

[0010]

[0011] Further, the organic weak oxidant is nicotinamide-N-oxide.

[0012] Further, the mass ratio of the sulfonic acid derivative to the organic weak oxidant is (4-6):1.

[0013] Further, the corrosion inhibitor is at least one of benzotriazole, benzimidazole, benzoquinoline, benzopyridine, benzopyrazine, and benzisoxazole.

[0014] Further, the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea and / or 3-aminopropylphosphonic acid.

[0015] Further, the surfactant is at least one of alkylphenol polyoxyethylene ether, polyethylene glycol, polyether-modified polysiloxane, and fatty alcohol polyoxyethylene ether.

[0016] In a second aspect, the present invention provides a preparation method of a Cu-ITO etching solution, which comprises the following steps:

[0017] S1. Weigh hydrogen peroxide, sulfonic acid derivative, organic weak oxidant, corrosion inhibitor, hydrogen peroxide stabilizer, surfactant, and water according to the Cu-ITO etching solution formula;

[0018] S2. Stir the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to prepare a mixed solution;

[0019] S3. Add a surfactant to the mixed solution obtained in step S2, stir at room temperature, then return to room temperature, add hydrogen peroxide and organic weak oxidant, and stir at room temperature until all the materials are uniformly mixed to obtain a Cu-ITO etching solution.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] 1. The Cu-ITO etching solution provided by the present invention includes hydrogen peroxide, sulfonic acid derivative, organic weak oxidant, corrosion inhibitor, hydrogen peroxide stabilizer, and surfactant. When the etching solution contacts the Cu-ITO substrate, hydrogen peroxide quickly undergoes an oxidation-reduction reaction with the copper layer, oxidizing copper to copper ions. After the copper layer is etched away, the sulfonic acid derivative begins to react with ITO, causing indium and tin in ITO to enter the solution in the form of ions, thereby achieving the etching of the ITO layer.

[0022] 2. In the present invention, the sulfonic acid derivative is 4,4'-((4-sulfophenyl)azanediyl)bis(methylene)dibenzoic acid. The sulfonic group and carboxyl group can react with indium tin oxide, thereby destroying the stability of the ITO crystal and making it easier to be etched by the etching solution, effectively improving the removal effect of etching residues on ITO. At the same time, 4,4'-((4-sulfophenyl)azanediyl)bis(methylene)dibenzoic acid can undergo a complexation reaction with copper ions. On the one hand, it orderly regulates the etching rates of Cu and ITO, avoids over-etching, helps to precisely control the etching degree of the Cu-ITO substrate, and on the other hand, improves the stability of the etching solution and extends the service life of the etching solution.

[0023] 3. In the present invention, the organic weak oxidant is nicotinamide-N-oxide, which has weak oxidizing property. Combining with hydrogen peroxide and sulfonic acid derivative, it can better etch the Cu-ITO substrate, and nicotinamide-N-oxide can directionally capture copper ions to prevent the decomposition of hydrogen peroxide catalyzed by copper ions, thereby stabilizing the performance of the etching solution and extending the service life of the etching solution.

[0024] 4. In the present invention, the sulfonic acid derivative and the organic weak oxidant are added to the etching solution in a specific mass ratio. They interact with each other, with stable etching performance, effectively adjusting the etching rate, improving the uniformity of etching, and obtaining a smoother etching surface. Description of the Drawings

[0025] The drawings described herein are used to provide a further understanding of the present invention, form a part of this application, and the schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0026] Figure 1 It is the SEM image of the substrate after etching the Cu-ITO substrate with the Cu-ITO etching solution provided in Embodiment 1 of the present invention;

[0027] Figure 2 It is the SEM image of the substrate after etching the Cu-ITO substrate with the Cu-ITO etching solution provided in Embodiment 2 of the present invention;

[0028] Figure 3 It is the SEM image of the substrate after etching the Cu-ITO substrate with the Cu-ITO etching solution provided in Embodiment 3 of the present invention;

[0029] Figure 4 It is the SEM image of the substrate after etching the Cu-ITO substrate with the Cu-ITO etching solution provided in Embodiment 4 of the present invention;

[0030] Figure 5 It is the SEM image of the substrate after etching the Cu-ITO substrate with the Cu-ITO etching solution provided in Embodiment 5 of the present invention;

[0031] Figure 6 It is the SEM image of the substrate after etching the Cu-ITO substrate with the Cu-ITO etching solution provided in Comparative Example 1 of the present invention;

[0032] Figure 7 It is the SEM image of the substrate after etching the Cu-ITO substrate with the Cu-ITO etching solution provided in Comparative Example 2 of the present invention;

[0033] Figure 8 It is the SEM image of the substrate after etching the Cu-ITO substrate with the Cu-ITO etching solution provided in Comparative Example 3 of the present invention;

[0034] Figure 9 It is the SEM image of the substrate after etching the Cu-ITO substrate with the Cu-ITO etching solution provided in Comparative Example 4 of the present invention;

[0035] Figure 10 It is the SEM image of the substrate after etching the Cu-ITO substrate with the Cu-ITO etching solution provided in Comparative Example 5 of the present invention. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] Embodiment 1

[0038] This embodiment provides a Cu-ITO etching solution, which comprises raw materials with the following mass fractions: 8% hydrogen peroxide, 6% sulfonic acid derivative, 1.5% organic weak oxidant, 0.1% corrosion inhibitor, 0.05% hydrogen peroxide stabilizer, 1% surfactant, and the balance is water;

[0039] Among them, the sulfonic acid derivative is 4,4'-((4-sulfophenyl)aza-diyl)bis(methylene)dibenzoic acid; the organic weak oxidant is nicotinamide-N-oxide; the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; the surfactant is alkylphenol polyoxyethylene ether;

[0040] This embodiment also provides a preparation method of the Cu-ITO etching solution, which comprises the following steps:

[0041] S1. Weigh each component in their respective dosages;

[0042] S2. Stir the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0043] S3. Add the surfactant to the mixed solution obtained in step S2, stir at room temperature, restore to room temperature, add hydrogen peroxide and organic weak oxidant, and stir at room temperature until all the materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0044] Example 2

[0045] This embodiment provides a Cu-ITO etching solution, which comprises raw materials with the following mass fractions: 12% hydrogen peroxide, 5.5% sulfonic acid derivative, 1.25% organic weak oxidant, 0.5% corrosion inhibitor, 0.1% hydrogen peroxide stabilizer, 1.5% surfactant, and the balance is water;

[0046] Among them, the sulfonic acid derivative is 4,4'-((4-sulfophenyl)aza-diyl)bis(methylene)dibenzoic acid; the organic weak oxidant is nicotinamide-N-oxide; the corrosion inhibitor is benzimidazole; the hydrogen peroxide stabilizer is 3-aminopropylphosphonic acid; the surfactant is polyethylene glycol;

[0047] This embodiment also provides a preparation method of the Cu-ITO etching solution, which comprises the following steps:

[0048] S1. Weigh each component in their respective dosages;

[0049] S2. Stir the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0050] S3. Add a surfactant to the mixture obtained in step S2, stir at room temperature, restore to room temperature, add hydrogen peroxide and an organic weak oxidant, and stir at room temperature until all the materials are evenly mixed to obtain a Cu-ITO etching solution.

[0051] Example 3

[0052] This example provides a Cu-ITO etching solution, which includes raw materials with the following mass fractions: 15% hydrogen peroxide, 5.1% sulfonic acid derivative, 1% organic weak oxidant, 1% corrosion inhibitor, 0.35% hydrogen peroxide stabilizer, 2% surfactant, and the balance is water.

[0053] Among them, the sulfonic acid derivative is 4,4'-((4-sulfophenyl)aza-diyl)bis(methylene)dibenzoic acid; the organic weak oxidant is nicotinamide-N-oxide; the corrosion inhibitor is obtained by mixing benzotriazole and benzopyrazine in a mass ratio of 1:1; the hydrogen peroxide stabilizer is obtained by mixing 1,3-diethyl-1,3-diphenylurea and 3-aminopropylphosphonic acid in a mass ratio of 1:1; the surfactant is polyether-modified polysiloxane.

[0054] This example also provides a preparation method of a Cu-ITO etching solution, which includes the following steps:

[0055] S1. Weigh each component in their respective dosages.

[0056] S2. Stir the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixture.

[0057] S3. Add a surfactant to the mixture obtained in step S2, stir at room temperature, restore to room temperature, add hydrogen peroxide and an organic weak oxidant, and stir at room temperature until all the materials are evenly mixed to obtain a Cu-ITO etching solution.

[0058] Example 4

[0059] This example provides a Cu-ITO etching solution, which includes raw materials with the following mass fractions: 16% hydrogen peroxide, 4.5% sulfonic acid derivative, 0.75% organic weak oxidant, 1.5% corrosion inhibitor, 0.5% hydrogen peroxide stabilizer, 2.5% surfactant, and the balance is water.

[0060] Among them, the sulfonic acid derivative is 4,4'-((4-sulfophenyl)aza-diyl)bis(methylene)dibenzoic acid; the organic weak oxidant is nicotinamide-N-oxide; the corrosion inhibitor is benzopyrazine; the hydrogen peroxide stabilizer is obtained by mixing 1,3-diethyl-1,3-diphenylurea and 3-aminopropylphosphonic acid in a mass ratio of 2:1; the surfactant is fatty alcohol polyoxyethylene ether.

[0061] This embodiment also provides a preparation method of a Cu-ITO etching solution, which includes the following steps:

[0062] S1. Weigh each component in their respective amounts;

[0063] S2. Stir the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0064] S3. Add a surfactant to the mixed solution obtained in step S2, stir at room temperature, restore to room temperature, add hydrogen peroxide and organic weak oxidant, and stir at room temperature until all the materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0065] Example 5

[0066] This embodiment provides a Cu-ITO etching solution, which includes the following raw materials by mass fraction: 18% hydrogen peroxide, 3% sulfonic acid derivative, 0.5% organic weak oxidant, 2% corrosion inhibitor, 1% hydrogen peroxide stabilizer, 3% surfactant, and the balance is water;

[0067] Among them, the sulfonic acid derivative is 4,4'-((4-sulfophenyl)aza-diyl)bis(methylene)dibenzoic acid; the organic weak oxidant is nicotinamide-N-oxide; the corrosion inhibitor is benzoquinoline; the hydrogen peroxide stabilizer is obtained by mixing 1,3-diethyl-1,3-diphenylurea and 3-aminopropylphosphonic acid in a mass ratio of 1:2; the surfactant is fatty acid polyoxyethylene ether;

[0068] This embodiment also provides a preparation method of a Cu-ITO etching solution, which includes the following steps:

[0069] S1. Weigh each component in their respective amounts;

[0070] S2. Stir the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0071] S3. Add a surfactant to the mixed solution obtained in step S2, stir at room temperature, restore to room temperature, add hydrogen peroxide and organic weak oxidant, and stir at room temperature until all the materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0072] Comparative Example 1

[0073] This comparative example provides a Cu-ITO etching solution and its preparation method. The difference from Example 1 is that in this comparative example, the sulfonic acid derivative is 4-aminobenzenesulfonic acid, specifically as follows:

[0074] A Cu-ITO etching solution, comprising raw materials with the following mass fractions: 8% hydrogen peroxide, 6% sulfonic acid derivative, 1.5% organic weak oxidant, 0.1% corrosion inhibitor, 0.05% hydrogen peroxide stabilizer, 1% surfactant, and the balance being water;

[0075] Among them, the sulfonic acid derivative is 4-aminobenzenesulfonic acid; the organic weak oxidant is nicotinamide-N-oxide; the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; the surfactant is alkylphenol polyoxyethylene ether;

[0076] A preparation method of a Cu-ITO etching solution, comprising the following steps:

[0077] S1. Weigh each component in their respective amounts;

[0078] S2. Stir the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0079] S3. Add the surfactant to the mixed solution obtained in step S2, stir at room temperature, restore to room temperature, add hydrogen peroxide and the organic weak oxidant, and stir at room temperature until all the materials are uniformly mixed to obtain the Cu-ITO etching solution.

[0080] Comparative Example 2

[0081] This comparative example provides a Cu-ITO etching solution and its preparation method. The difference from Example 1 is that in this comparative example, the organic weak oxidant is N-methylmorpholine-N-oxide, specifically as follows:

[0082] A Cu-ITO etching solution, comprising raw materials with the following mass fractions: 8% hydrogen peroxide, 6% sulfonic acid derivative, 1.5% organic weak oxidant, 0.1% corrosion inhibitor, 0.05% hydrogen peroxide stabilizer, 1% surfactant, and the balance being water;

[0083] Among them, the sulfonic acid derivative is 4,4'-((4-sulfophenyl)aza-diyl)bis(methylene)dibenzoic acid; the organic weak oxidant is N-methylmorpholine-N-oxide; the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; the surfactant is alkylphenol polyoxyethylene ether;

[0084] A preparation method of a Cu-ITO etching solution, comprising the following steps:

[0085] S1. Weigh each component in their respective amounts;

[0086] S2. Stir the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0087] S3. Add a surfactant to the mixed solution obtained in step S2, stir at room temperature, restore to room temperature, add hydrogen peroxide and organic weak oxidant, and stir at room temperature until all the materials are uniformly mixed to obtain a Cu-ITO etching solution.

[0088] Comparative Example 3

[0089] This comparative example provides a Cu-ITO etching solution and its preparation method. The difference from Example 1 is that in this comparative example, the sulfonic acid derivative is 7% and the organic weak oxidant is 1%. Specifically as follows:

[0090] A Cu-ITO etching solution comprising the following raw materials in mass fractions: 8% hydrogen peroxide, 7% sulfonic acid derivative, 1% organic weak oxidant, 0.1% corrosion inhibitor, 0.05% hydrogen peroxide stabilizer, 1% surfactant, and the balance is water;

[0091] Among them, the sulfonic acid derivative is 4,4'-((4-sulfophenyl)azanyldiyl)bis(methylene)dibenzoic acid; the organic weak oxidant is nicotinamide-N-oxide; the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; the surfactant is alkylphenol polyoxyethylene ether;

[0092] A preparation method of a Cu-ITO etching solution, comprising the following steps:

[0093] S1. Weigh each component in their respective dosages;

[0094] S2. Stir the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0095] S3. Add a surfactant to the mixed solution obtained in step S2, stir at room temperature, restore to room temperature, add hydrogen peroxide and organic weak oxidant, and stir at room temperature until all the materials are uniformly mixed to obtain a Cu-ITO etching solution.

[0096] Comparative Example 4

[0097] This comparative example provides a Cu-ITO etching solution and its preparation method. The difference from Example 1 is that in this comparative example, the sulfonic acid derivative is 1% and the organic weak oxidant is 5.5%. Specifically as follows:

[0098] A Cu-ITO etching solution, comprising raw materials in the following mass fractions: 8% hydrogen peroxide, 1% sulfonic acid derivative, 5.5% organic weak oxidant, 0.1% corrosion inhibitor, 0.05% hydrogen peroxide stabilizer, 1% surfactant, and the balance being water;

[0099] Among them, the sulfonic acid derivative is 4,4'-((4-sulfophenyl)azanediyl)bis(methylene)dibenzoic acid; the organic weak oxidant is nicotinamide-N-oxide; the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; the surfactant is alkylphenol polyoxyethylene ether;

[0100] A preparation method of a Cu-ITO etching solution, comprising the following steps:

[0101] S1. Weigh each component in their respective dosages;

[0102] S2. Stir the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0103] S3. Add the surfactant to the mixed solution obtained in step S2, stir at room temperature, restore to room temperature, add hydrogen peroxide and organic weak oxidant, and stir at room temperature until all the materials are uniformly mixed to obtain a Cu-ITO etching solution.

[0104] Comparative Example 5

[0105] This comparative example provides a Cu-ITO etching solution and its preparation method, specifically as follows:

[0106] A Cu-ITO etching solution, comprising raw materials in the following weight percentages: 8% hydrogen peroxide, 6% nitric acid, 1.5% hydrogen fluoride, 0.1% corrosion inhibitor, 0.05% hydrogen peroxide stabilizer, 1% surfactant, and the balance being water;

[0107] Among them, the corrosion inhibitor is benzotriazole; the hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea; the surfactant is alkylphenol polyoxyethylene ether;

[0108] A preparation method of a Cu-ITO etching solution, comprising the following steps:

[0109] S1. Weigh each component in their respective dosages;

[0110] S2. Stir the nitric acid, hydrogen fluoride, corrosion inhibitor, hydrogen peroxide stabilizer and water at room temperature until all the materials are completely dissolved to obtain a mixed solution;

[0111] S3. Add a surfactant to the mixture obtained in step S2, stir at room temperature, restore to room temperature, add hydrogen peroxide, and stir at room temperature until all materials are evenly mixed to obtain a Cu-ITO etching solution.

[0112] Performance Test

[0113] Perform performance tests on the Cu-ITO etching solutions provided in Examples 1-5 and Comparative Examples 1-5. The relevant test items and test procedures are as follows.

[0114] (1) Stability performance test of the etching solution

[0115] Place the etching solution in the dark at room temperature and investigate the etching rates of the etching solution at the initial stage, 8h, 16h, and 24h respectively to examine its stability. The test method for the etching rate is as follows: Use the four-probe method to evenly select five points on the surface of the Cu sample (or ITO sample) for testing, and take the average value to measure the initial thickness of the material; Immerse the samples in the etching solutions obtained in Examples 1-5 and Comparative Examples 1-5 at 33°C for 50s, and then obtain Cu samples (or ITO samples) with the expected thickness; Rinse the etched samples twice with ultrapure water to complete the rinsing step; Use the four-probe method to test on the surface of the etched samples, evenly select five points and take the average value to measure the thickness of the thinned samples and make a difference from the thickness of the samples before etching, and divide by the etching time of the samples to obtain the etching rate of the samples. The specific results are shown in Table 1.

[0116] Table 1

[0117]

[0118] (2) Etching effect test of the etching solution

[0119] Test the etching effects of the etching solutions obtained in Examples 1-5 and Comparative Examples 1-5. At 33°C, use an etching machine to etch the Cu-ITO substrate (Cu layer: ITO layer: ), and observe the Taper angle and ITO tail length through SEM to evaluate the etching effect of the etching solution. The specific results are shown in Table 2 and Figure 1-10 as shown, where Figure 1-5 are the SEM images of the substrates after etching the Cu-ITO substrates with the Cu-ITO etching solutions provided in Examples 1-5 respectively, Figure 6-10 are the SEM images of the substrates after etching the Cu-ITO substrates with the Cu-ITO etching solutions provided in Comparative Examples 1-5 respectively.

[0120] Table 2

[0121] Taper Angle / ° ITOTail / μm Example 1 44.07 0.1389 Example 2 44.08 0.1091 Example 3 44.72 0.0907 Example 4 45.00 0.1190 Example 5 45.43 0.1276 Comparative Example 1 47.14 0.2012 Comparative Example 2 44.57 0.1885 Comparative Example 3 48.00 0.1701 Comparative Example 4 40.89 0.1587 Comparative Example 5 61.83 0.1332

[0122] Combining the data in Table 1 and Table 2, it can be seen that the Cu-ITO etching solutions obtained in Examples 1-5 still maintained excellent and stable etching rates after being placed for 24 hours, and were able to effectively etch Cu wafers and ITO wafers. At the same time, based on the data in Table 2 and Figure 1-10 it can be known that the Taper angle of the Cu-ITO substrates etched by the Cu-ITO etching solutions obtained in Examples 1-5 was stably between 44-46°, and the ITO Tail parameter was less than 0.15 μm, meeting the requirements of the production process, which fully demonstrates that the Cu-ITO etching solution of the present invention has the excellent characteristics of long life and stable etching performance.

[0123] Comparing Example 1 with Comparative Example 1, it can be seen that in the present invention, 4,4'-((4-sulfophenyl)azanediyl)bis(methylene)dibenzoic acid is used as the sulfonic acid derivative. Compared with 4-aminobenzenesulfonic acid, 4,4'-((4-sulfophenyl)azanediyl)bis(methylene)dibenzoic acid can not only effectively etch the ITO layer and destroy the stability of the ITO crystal, but also is beneficial to maintaining the etching stability of the etching solution.

[0124] Comparing Example 1 with Comparative Example 2, it can be seen that in the present invention, nicotinamide-N-oxide is used as the organic weak oxidant. Compared with N-methylmorpholine-N-oxide, nicotinamide-N-oxide is more helpful to prevent the characteristics of the etching solution from changing, increase the stability of the etching composition, and enable the etching solution to maintain a stable etching rate.

[0125] Comparing Example 1 with Comparative Examples 3 and 4, it can be seen that in the present invention, the sulfonic acid derivative and the organic weak oxidant are added to the etching solution in a specific mass ratio, and the two interact with each other and synergistically enhance the effect, enabling the etching solution to maintain good etching ability for a long time.

[0126] Comparing Example 1 with Comparative Example 5, it can be seen that the etching solution of the present invention does not include nitric acid and hydrogen fluoride, and is composed of hydrogen peroxide, sulfonic acid derivative, organic weak oxidant, corrosion inhibitor, hydrogen peroxide stabilizer, and surfactant. The components interact with each other, enabling the etching solution to etch the Cu-ITO substrate in one step, with a stable etching rate, and being green and environmentally friendly with little pollution.

[0127] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0128] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and all these changes and improvements fall within the scope of the present invention claimed.

Claims

1. A Cu-ITO etching solution, characterized in that, By mass percentage, it comprises the following components: 8-18% of hydrogen peroxide, 3-6% of sulfonic acid derivative, 0.5-1.5% of organic weak oxidant, 0.1-2% of corrosion inhibitor, 0.05-1% of hydrogen peroxide stabilizer, 1-3% of surfactant, and the balance is water.

2. The Cu-ITO etching solution according to claim 1, characterized in that, By mass percentage, it comprises the following components: 12-16% of hydrogen peroxide, 4.5-5.5% of sulfonic acid derivative, 0.75-1.25% of organic weak oxidant, 0.5-1.5% of corrosion inhibitor, 0.1-0.5% of hydrogen peroxide stabilizer, 1.5-2.5% of surfactant, and the balance is water.

3. A Cu-ITO etching solution according to claim 1, wherein, The sulfonic acid derivative is 4,4'-((4-sulfophenyl)azanediyl)bis(methylene)dibenzoic acid.

4. A Cu-ITO etching solution according to claim 1, wherein, The organic weak oxidant is nicotinamide-N-oxide.

5. A Cu-ITO etching solution according to claim 1, characterized in that, The mass ratio of the sulfonic acid derivative to the organic weak oxidant is (4-6):

1.

6. A Cu-ITO etching solution according to claim 1, characterized in that, The corrosion inhibitor is at least one of benzotriazole, benzimidazole, benzoquinoline, benzopyridine, benzopyrazine, and benzisoxazole.

7. A Cu-ITO etching solution according to claim 1, wherein, The hydrogen peroxide stabilizer is 1,3-diethyl-1,3-diphenylurea and / or 3-aminopropylphosphonic acid.

8. A Cu-ITO etching solution according to claim 1, wherein, The surfactant is at least one of alkylphenol polyoxyethylene ether, polyethylene glycol, polyether-modified polysiloxane, fatty alcohol polyoxyethylene ether, and fatty acid polyoxyethylene ether.

9. The preparation method of the Cu-ITO etching solution according to any one of claims 1-8, characterized in that, It comprises the following steps: S1. Weigh hydrogen peroxide, sulfonic acid derivative, organic weak oxidant, corrosion inhibitor, hydrogen peroxide stabilizer, surfactant, and water according to the Cu-ITO etchant formula. S2. Stir the sulfonic acid derivative, corrosion inhibitor, hydrogen peroxide stabilizer, and water at room temperature until all the materials are completely dissolved to prepare a mixed solution. S3. Add the surfactant to the mixed solution obtained in step S2, stir at room temperature, then return to room temperature, add hydrogen peroxide and organic weak oxidant, and stir at room temperature until all the materials are uniformly mixed to obtain the Cu-ITO etchant.

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