ITO-Ag-ITO etching solution, preparation method and application thereof

Abstract

The present invention belongs to the technical field of etching, surface brightening or pickling compositions, and specifically relates to an ITO-Ag-ITO etching solution, a preparation method thereof, and an application thereof. The solution comprises the following components in percentage by mass: 15-30% tartaric acid, 8-20% sulfocarboxylic acid, 5-15% bisulfate, 3-10% nitric acid, 2-6% sugar alcohol compound, 0.1-5% polyetheramine, 0.01-1% corrosion inhibitor, and the remainder is water. The above components interact with each other to adjust the etching selectivity, etch uniformly, reduce the undesirable phenomena such as partial shedding of the Ag film, black spots, dark spots or short circuits; reduce the activity of the etching solution on Al, and will not cause Al side corrosion; and inhibit Ag through the complexation-dispersion-adsorption multiple mechanisms. + The reduction reaction reduces the residual silver particles after etching and the precipitation in areas such as Al, greatly improving pattern accuracy and significantly increasing the product yield in the OLED process. It solves the problems of ITO and Ag etching differences, silver residue, silver precipitation, and metal Al corrosion in existing technologies.

Description

Technical Field

[0001] The invention belongs to the technical field of etching, surface brightening or pickling compositions, and particularly relates to an ITO-Ag-ITO etching solution and a preparation method and application thereof. Background Art

[0002] With the rapid development of semiconductor and display technologies, metallic silver, as an excellent target material, has excellent electrical and thermal conductivity, making it play an important role in the electronics industry. For example, it is used to manufacture high-precision circuit boards, electronic connectors and other components. In addition, metallic silver has good ductility and plasticity, and can be processed into various complex shapes and fine structures to meet the design requirements of different products. At the same time, metallic silver has relatively high chemical stability and is not easily oxidized and corroded under certain conditions. It can maintain good performance and appearance during long-term use. However, in actual application fields, metallic silver has insufficient adhesion when evaporated or electroplated on silicon-based materials, often leading to undesirable phenomena such as warping and falling off. Therefore, silver targets are often used in combination with indium tin oxide (ITO) in actual use to achieve better adhesion.

[0003] When existing silver etching solutions are used to etch multi-layer films composed of silver thin films and ITO films, uneven etching often occurs, resulting in not only a large amount of Ag residue but also partial detachment of the silver film layer on the circuit, resulting in black spots, dark spots or short circuits.

[0004] In addition, in the OLED process of the display industry, some special areas of the display panel will use metal circuits of the Al process; in the silver etching process, an etching solution of phosphoric acid, nitric acid, and acetic acid system is usually used. This etching solution system is highly corrosive to the Al process circuits; in the exposed area of ​​the Al process, due to the activity of the metal, more and larger metallic silver particles are easily precipitated in this area, which will seriously affect the product yield.

[0005] Therefore, it is necessary to develop an ITO-Ag-ITO etching solution that can solve the above problems. Summary of the Invention

[0006] One of the purposes of the present invention is to provide an ITO-Ag-ITO etching solution to improve the technical defects of existing silver etching solutions and greatly improve the etching differences between ITO and Ag, silver residue, silver precipitation and metal Al corrosion problems.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an ITO-Ag-ITO etching solution, comprising the following components in mass percentage: 15-30% tartaric acid, 8-20% sulfocarboxylic acid, 5-15% bisulfate, 3-10% nitric acid, 2-6% sugar alcohol compound, 0.1-5% polyetheramine, 0.01-1% corrosion inhibitor, and the balance being water.

[0008] As a further improvement of ITO-Ag-ITO etching solution:

[0009] Preferably, the sulfocarboxylic acid is any one of 2-sulfoacetic acid, 3-sulfopropionic acid, sulfosuccinic acid, sulfobenzoic acid, sulfophthalic acid, sulfosalicylic acid, and 4,8-disulfonaphthalene-2,6-dicarboxylic acid, or a combination of two or more thereof.

[0010] Preferably, the sulfocarboxylic acid is obtained by mixing 2-sulfoacetic acid and 4,8-disulfonaphthalene-2,6-dicarboxylic acid in a mass ratio of (3-7):2.

[0011] The sulfocarboxylic acid of the present invention contains a carboxyl group and a sulfonic acid group, which can be simultaneously adsorbed on the surface of metallic silver to form a double coordination complex structure, thereby enhancing the complexing ability of silver ions and reducing the concentration of free silver ions. The present invention further preferably uses a short-chain sulfocarboxylic acid compounded with a long-chain aromatic sulfocarboxylic acid. The molecular weight of 2-sulfoacetic acid is small and the acidity is strong, which can quickly dissolve the Ag layer, shorten the etching time, and reduce the concentration of Ag. + The residence time in the solution is shortened, thereby inhibiting its diffusion and precipitation into the Al region; the large naphthalene ring structure of 4,8-disulfonaphthalene-2,6-dicarboxylic acid has orientational adsorption on the Ag surface, forming a molecular fence, which effectively prevents the hydrogen ions in the etching solution from excessively attacking the ITO layer, regulating the etching rate between ITO and Ag, and the hydrophobic effect of the naphthalene ring can reduce the Ag + The diffusion coefficient in the solution further reduces its migration to the Al area and inhibits silver precipitation; 2-sulfoacetic acid and 4,8-disulfonaphthalene-2,6-dicarboxylic acid are mixed in a specific mass ratio, and the two interact with each other to significantly improve the etching difference between ITO and Ag, effectively preventing the silver film layer on the circuit from falling off, greatly reducing the occurrence of black spots, dark spots or short circuits and other undesirable phenomena, and reducing corrosion to metal Al, avoiding silver precipitation.

[0012] Preferably, the bisulfate is any one of ammonium bisulfate, sodium bisulfate, and potassium bisulfate, or a combination of two or more thereof.

[0013] The present invention preferably uses hydrogen sulfate, which helps to shorten the time of etching the Ag layer, thereby reducing the contact time between the etching solution and the ITO layer, regulating the etching rates of ITO and Ag, and effectively avoiding the occurrence of undercutting. In addition, hydrogen sulfate effectively inhibits the diffusion of silver ions in the etching solution to the Al area, effectively avoiding damage to the Al layer, preventing the occurrence of side etching, and helping to avoid the formation of undesirable phenomena such as black spots, dark spots, and residues.

[0014] Preferably, the sugar alcohol compound is any one of sorbitol, mannitol, xylitol, maltitol, threitol, erythritol, ribitol, fucitol, galactitol, arabitol, and iditol, or a combination of two or more thereof.

[0015] The preferred sugar alcohol compound of the present invention can enhance the wettability of the etching solution on the metal surface and reduce the uneven etching caused by bubble adhesion. Moreover, it contains multiple hydroxyl groups and can form a stable complex with silver ions through complexation, thereby greatly reducing the situation of silver residue and silver precipitation.

[0016] Preferably, the molecular weight of the polyetheramine is 400-1000.

[0017] Preferably, the polyetheramine is any one of polyetheramine D400, polyetheramine D600, and polyetheramine D800, or a combination of two or more thereof.

[0018] The present invention prefers polyetheramine. On the one hand, the ether oxygen atoms in the polyetheramine molecular chain will be adsorbed on the Ag surface, regulating the etching rate between ITO and Ag. On the other hand, the amino groups of the polyetheramine will also be adsorbed on the defect sites of the Al / Al2O3 interface, forming a dense organic protective film, blocking the etching factor from contacting Al and reducing the corrosion rate. When the molecular weight of the polyetheramine is less than 400, the ratio of the hydrophilic amino group to the ether bond is high, and the polyetheramine is too hydrophilic. It may preferentially react with tartaric acid and sulfocarboxylic acid in the etching solution, resulting in a decrease in its complexing ability for metal ions, causing excessive etching of the Ag layer or corrosion of the Al substrate. When the molecular weight of the polyetheramine is greater than 1000, the hydrophobic chain segment increases, the solubility in the etching solution is poor, and the solution will become turbid or stratified, resulting in uneven etching. Therefore, the molecular weight of the polyetheramine is strictly controlled between 400 and 1000 to ensure that the polyetheramine can be evenly dispersed in the aqueous phase, and can better form a stable synergistic system with other components, thereby improving the reliability and yield of the etching process.

[0019] Preferably, the corrosion inhibitor is an azole compound; the azole compound is any one of methylbenzotriazole, benzotriazole, and 5-aminotetrazole, or a combination of two or more thereof.

[0020] A second object of the present invention is to provide a method for preparing the above-mentioned ITO-Ag-ITO etching solution, comprising the following steps: weighing the raw materials, mixing them uniformly in a container, and stirring them until they are completely dissolved.

[0021] A third object of the present invention is to provide an application of the above-mentioned ITO-Ag-ITO etching solution in etching an indium tin oxide film, a silver film, or an alloy film of an indium tin oxide film and a silver film.

[0022] The beneficial effects of the present invention compared to the prior art are:

[0023] The components in the etching solution of the present invention interact with each other, effectively adjusting the etching selectivity of ITO and Ag, etching uniformly, reducing the adverse phenomena such as partial shedding of the Ag film layer, black spots, dark spots or short circuits caused by etching differences; reducing the activity of the etching solution on Al, without corroding the exposed metal Al area and causing Al side corrosion; and inhibiting Ag through the complexation-dispersion-adsorption multiple mechanisms. + The reduction reaction reduces the residual silver particles after etching and the precipitation in areas such as Al, greatly improving the pattern accuracy and significantly improving the product yield in the OLED process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 are microscope images after etching using the etching solution of Example 1, wherein (a) and (b) are the OM image and SEM electron microscope image of region 1, respectively, and (c) and (d) are the OM image and SEM electron microscope image of region 2, respectively;

[0025] Figure 2 These are microscope images after etching using the etching solution of Example 2, wherein (a) and (b) are the OM image and SEM electron microscope image of region 1, respectively, and (c) and (d) are the OM image and SEM electron microscope image of region 2, respectively;

[0026] Figure 3 are microscope images after etching using the etching solution of Example 3, wherein (a) and (b) are the OM image and SEM electron microscope image of region 1, respectively, and (c) and (d) are the OM image and SEM electron microscope image of region 2, respectively;

[0027] Figure 4 are microscope images after etching using the etching solution of Example 4, wherein (a) and (b) are the OM image and SEM electron microscope image of region 1, respectively, and (c) and (d) are the OM image and SEM electron microscope image of region 2, respectively;

[0028] Figure 5 are microscope images after etching using the etching solution of Example 5, wherein (a) and (b) are the OM image and SEM electron microscope image of region 1, respectively, and (c) and (d) are the OM image and SEM electron microscope image of region 2, respectively;

[0029] Figure 6 are microscope images after etching using the etching solution of Example 6, wherein (a) and (b) are the OM image and SEM electron microscope image of region 1, respectively, and (c) and (d) are the OM image and SEM electron microscope image of region 2, respectively;

[0030] Figure 7 are microscope images after etching using the etching solution of Example 7, wherein (a) and (b) are the OM image and SEM electron microscope image of region 1, respectively, and (c) and (d) are the OM image and SEM electron microscope image of region 2, respectively;

[0031] Figure 8 These are microscope images after etching using the etching solution of Comparative Example 1, where (a) and (b) are the OM image and SEM electron microscope image of region 1, respectively; (c) and (d) are the OM image and SEM electron microscope image of region 2, respectively;

[0032] Figure 9 These are microscope images after etching using the etching solution of Comparative Example 2, where (a) and (b) are the OM image and SEM electron microscope image of region 1, respectively; (c) and (d) are the OM image and SEM electron microscope image of region 2, respectively;

[0033] Figure 10 These are microscope images after etching using the etching solution of Comparative Example 3, where (a) and (b) are the OM image and SEM electron microscope image of region 1, respectively; and (c) and (d) are the OM image and SEM electron microscope image of region 2, respectively;

[0034] Figure 11 It is the original piece in the OLED manufacturing process, where area 1 is the packaging module and area 2 is the pixel area. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] Example 1

[0037] This embodiment provides an ITO-Ag-ITO etching solution, comprising the following components in percentage by weight: 25% tartaric acid, 18% sulfocarboxylic acid, 15% bisulfate, 7% nitric acid, 3% sugar alcohol compound, 5% polyetheramine, 0.01% corrosion inhibitor, and the balance being water;

[0038] The sulfocarboxylic acid is obtained by mixing 2-sulfoacetic acid and 4,8-disulfonaphthalene-2,6-dicarboxylic acid in a mass ratio of 3:2; the bisulfate is sodium bisulfate; the sugar alcohol compound is sorbitol; the polyetheramine is polyetheramine D400; and the corrosion inhibitor is methylbenzotriazole.

[0039] The preparation method of the above-mentioned ITO-Ag-ITO etching solution comprises the following steps: weighing the above-mentioned raw materials in the mass percentage, mixing them evenly in a container, and stirring them until they are completely dissolved.

[0040] Example 2

[0041] This embodiment provides an ITO-Ag-ITO etching solution, comprising the following components in percentage by weight: 30% tartaric acid, 8% sulfocarboxylic acid, 5% bisulfate, 3% nitric acid, 6% sugar alcohol compound, 2.5% polyetheramine, 0.5% corrosion inhibitor, and the balance being water;

[0042] The sulfocarboxylic acid is obtained by mixing 3-sulfopropionic acid and sulfophthalic acid in a mass ratio of 2:1; the bisulfate is potassium bisulfate; the sugar alcohol compound is obtained by mixing erythritol and maltitol in a mass ratio of 1:1; the polyetheramine is polyetheramine D600; and the corrosion inhibitor is 5-aminotetrazole.

[0043] The preparation method of the above-mentioned ITO-Ag-ITO etching solution comprises the following steps: weighing the above-mentioned raw materials in the mass percentage, mixing them evenly in a container, and stirring them until they are completely dissolved.

[0044] Example 3

[0045] This embodiment provides an ITO-Ag-ITO etching solution, comprising the following components in percentage by weight: 15% tartaric acid, 20% sulfocarboxylic acid, 10% bisulfate, 10% nitric acid, 2% sugar alcohol compound, 0.1% polyetheramine, 1% corrosion inhibitor, and the balance being water;

[0046] The sulfocarboxylic acid is obtained by mixing 2-sulfoacetic acid and 4,8-disulfonaphthalene-2,6-dicarboxylic acid in a mass ratio of 7:2; the bisulfate is ammonium bisulfate; the sugar alcohol compound is xylitol; the polyetheramine is polyetheramine D800; and the corrosion inhibitor is benzotriazole.

[0047] The preparation method of the above-mentioned ITO-Ag-ITO etching solution comprises the following steps: weighing the above-mentioned raw materials in the mass percentage, mixing them evenly in a container, and stirring them until they are completely dissolved.

[0048] Example 4

[0049] This embodiment provides an ITO-Ag-ITO etching solution, which differs from Example 1 only in that the sulfocarboxylic acid is 2-sulfoacetic acid. Specifically, the solution comprises the following components in percentage by weight: 25% tartaric acid, 18% sulfocarboxylic acid, 15% bisulfate, 7% nitric acid, 3% sugar alcohol compound, 5% polyetheramine, 0.01% corrosion inhibitor, and the balance water.

[0050] Wherein, the sulfocarboxylic acid is 2-sulfoacetic acid; the bisulfate is sodium bisulfate; the sugar alcohol compound is sorbitol; the polyetheramine is polyetheramine D400; and the corrosion inhibitor is methylbenzotriazole;

[0051] The preparation method of the above-mentioned ITO-Ag-ITO etching solution comprises the following steps: weighing the above-mentioned raw materials in the mass percentage, mixing them evenly in a container, and stirring them until they are completely dissolved.

[0052] Example 5

[0053] This embodiment provides an ITO-Ag-ITO etching solution, which differs from Example 1 only in that the sulfocarboxylic acid is 4,8-disulfonaphthalene-2,6-dicarboxylic acid, and specifically comprises the following components in percentage by weight: 25% tartaric acid, 18% sulfocarboxylic acid, 15% hydrogen sulfate, 7% nitric acid, 3% sugar alcohol compound, 5% polyetheramine, 0.01% corrosion inhibitor, and the balance is water;

[0054] Wherein, the sulfocarboxylic acid is 4,8-disulfonaphthalene-2,6-dicarboxylic acid; the bisulfate is sodium bisulfate; the sugar alcohol compound is sorbitol; the polyetheramine is polyetheramine D400; and the corrosion inhibitor is methylbenzotriazole;

[0055] The preparation method of the above-mentioned ITO-Ag-ITO etching solution comprises the following steps: weighing the above-mentioned raw materials in the mass percentage, mixing them evenly in a container, and stirring them until they are completely dissolved.

[0056] Example 6

[0057] This embodiment provides an ITO-Ag-ITO etching solution, which differs from Example 1 only in that the polyetheramine is polyetheramine EDR-176. Specifically, the solution comprises the following components in percentage by weight: 25% tartaric acid, 18% sulfocarboxylic acid, 15% bisulfate, 7% nitric acid, 3% sugar alcohol compound, 5% polyetheramine, 0.01% corrosion inhibitor, and the balance water.

[0058] The sulfocarboxylic acid is obtained by mixing 2-sulfoacetic acid and 4,8-disulfonaphthalene-2,6-dicarboxylic acid in a mass ratio of 3:2; the bisulfate is sodium bisulfate; the sugar alcohol compound is sorbitol; the polyetheramine is polyetheramine EDR-176; and the corrosion inhibitor is methylbenzotriazole.

[0059] The preparation method of the above-mentioned ITO-Ag-ITO etching solution comprises the following steps: weighing the above-mentioned raw materials in the mass percentage, mixing them evenly in a container, and stirring them until they are completely dissolved.

[0060] Example 7

[0061] This embodiment provides an ITO-Ag-ITO etching solution, which differs from Example 1 only in that the polyetheramine is polyetheramine D-2000, and specifically comprises the following components in percentage by weight: 25% tartaric acid, 18% sulfocarboxylic acid, 15% bisulfate, 7% nitric acid, 3% sugar alcohol compound, 5% polyetheramine, 0.01% corrosion inhibitor, and the balance is water;

[0062] The sulfocarboxylic acid is obtained by mixing 2-sulfoacetic acid and 4,8-disulfonaphthalene-2,6-dicarboxylic acid in a mass ratio of 3:2; the bisulfate is sodium bisulfate; the sugar alcohol compound is sorbitol; the polyetheramine is polyetheramine D-2000; and the corrosion inhibitor is methylbenzotriazole.

[0063] The preparation method of the above-mentioned ITO-Ag-ITO etching solution comprises the following steps: weighing the above-mentioned raw materials in the mass percentage, mixing them evenly in a container, and stirring them until they are completely dissolved.

[0064] Comparative Example 1

[0065] This comparative example provides an ITO-Ag-ITO etching solution, which differs from Example 1 only in that an equal amount of aminosulfonic acid is used instead of sulfocarboxylic acid. Specifically, the solution comprises the following components in percentage by weight: 25% tartaric acid, 18% aminosulfonic acid, 15% bisulfate, 7% nitric acid, 3% sugar alcohol compound, 5% polyetheramine, 0.01% corrosion inhibitor, and the balance water.

[0066] Wherein, the bisulfate is sodium bisulfate; the sugar alcohol compound is sorbitol; the polyetheramine is polyetheramine D400; and the corrosion inhibitor is methylbenzotriazole;

[0067] The preparation method of the above-mentioned ITO-Ag-ITO etching solution comprises the following steps: weighing the above-mentioned raw materials in the mass percentage, mixing them evenly in a container, and stirring them until they are completely dissolved.

[0068] Comparative Example 2

[0069] This comparative example provides an ITO-Ag-ITO etching solution, which differs from Example 1 only in that an equal amount of sulfate (sodium sulfate) is used instead of bisulfate (sodium bisulfate). Specifically, the solution comprises the following components in percentage by weight: 25% tartaric acid, 18% sulfocarboxylic acid, 15% sulfate, 7% nitric acid, 3% sugar alcohol compound, 5% polyetheramine, 0.01% corrosion inhibitor, and the balance water.

[0070] The sulfocarboxylic acid is obtained by mixing 2-sulfoacetic acid and 4,8-disulfonaphthalene-2,6-dicarboxylic acid in a mass ratio of 3:2; the sulfate is sodium sulfate; the sugar alcohol compound is sorbitol; the polyetheramine is polyetheramine D400; and the corrosion inhibitor is methylbenzotriazole.

[0071] The preparation method of the above-mentioned ITO-Ag-ITO etching solution comprises the following steps: weighing the above-mentioned raw materials in the mass percentage, mixing them evenly in a container, and stirring them until they are completely dissolved.

[0072] Comparative Example 3

[0073] This comparative example provides an ITO-Ag-ITO etching solution comprising the following components in percentage by mass: 50% phosphoric acid, 15% acetic acid, 5% nitric acid, 2% ammonium dihydrogen phosphate, and the balance being water;

[0074] The preparation method of the above-mentioned ITO-Ag-ITO etching solution comprises the following steps: weighing the above-mentioned raw materials in the mass percentage, mixing them evenly in a container, and stirring them until they are completely dissolved.

[0075] Performance Testing

[0076] 1. Etching method: At 40°C, an ITO-Ag-ITO sample (thickness of 68Å-1000Å-68Å) in an OLED process to be etched was immersed in Examples 1-7 and Comparative Examples 1-3 of the present invention for etching, wherein the EPD (time at which the ITO / Ag / ITO film etching ends) was 24s, the OE% (time at which the EPD is 1+X%) was 100%, and the etching time OE was 48s. The sample was then rinsed with ultrapure water for 1 min and finally dried with high-purity nitrogen.

[0077] 2. Etching effect evaluation: After cleaning, use OM to observe the plane of the sample and use SEM to observe the cross-section of the sample. OM is used to check whether there are black spots, dark spots, and whether the silver film layer is falling off. SEM is used to check the etching morphology of metallic silver and the degree of Al side etching. The specific evaluation criteria are as follows:

[0078] In OLED display panels, there are packaging modules and pixel areas. Specifically, the original film in the OLED process consists of Figure 11 As shown, area 1 is the packaging module, which includes Al process lines and is mainly used to provide internal and external circuit connections; area 2 is the pixel area, which is the core area of ​​the display function and is mainly responsible for light emission and light modulation, and is composed of ITO / Ag / ITO.

[0079] (1) Area 1

[0080] Evaluation of black spots and dark spots: 0: no black spots and dark spots; Δ: a small amount of black spots and dark spots; : A large number of black spots and dark spots;

[0081] Evaluation of Al side etching: Top is the horizontal distance of the upper metal Ti epitaxially based on the intermediate metal Al, and bottom is the horizontal distance of the lower metal Ti epitaxially based on the intermediate metal Al; among them, A: the values ​​of Top and Bottom are both less than 100nm; B: the value of Top or Bottom is between 100nm and 200nm; C: the value of Top or Bottom is between 200nm and 300nm; D: the values ​​of Top and Bottom are both greater than 300nm.

[0082] (2) Area 2

[0083] Whether the silver film layer has fallen off: √: no detachment; ×: detachment; the CD value (the horizontal distance between the indentation of the metal Ag layer and the outermost epitaxial layer of the photoresist) is used to represent the etching morphology of the metal silver;

[0084] The test results are as follows Figure 1-10 As shown in Table 1.

[0085] in, Figure 1 (a) is the OM image of area 1 after being etched using the etching solution of Example 1, (b) is the SEM electron microscope image of area 1 after being etched using the etching solution of Example 1, (c) is the OM image of area 2 after being etched using the etching solution of Example 1, and (d) is the SEM electron microscope image of area 2 after being etched using the etching solution of Example 1; Figure 1 It can be seen that: there are no black spots or dark spots in area 1 (a), the top and bottom side etching in area 1 (b) is less than 100nm, the pattern in area 2 (c) is not damaged or detached, and the etching value in area 2 (d) is 0.1<CD value<0.2μm, all of which meet the etching requirements.

[0086] Figure 2 (a) is the OM image of area 1 after being etched using the etching solution of Example 2, (b) is the SEM electron microscope image of area 1 after being etched using the etching solution of Example 2, (c) is the OM image of area 2 after being etched using the etching solution of Example 2, and (d) is the SEM electron microscope image of area 2 after being etched using the etching solution of Example 2; Figure 2 It can be seen that: there are no black spots or dark spots in area 1 (a), the top and bottom side etching in area 1 (b) is less than 100nm, the pattern in area 2 (c) is not damaged or detached, and the etching value in area 2 (d) is 0.1<CD value<0.2μm, all of which meet the etching requirements.

[0087] Figure 3(a) is the OM image of area 1 after being etched using the etching solution of Example 3, (b) is the SEM electron microscope image of area 1 after being etched using the etching solution of Example 3, (c) is the OM image of area 2 after being etched using the etching solution of Example 3, and (d) is the SEM electron microscope image of area 2 after being etched using the etching solution of Example 3; Figure 3 It can be seen that: there are no black spots or dark spots in area 1 (a), the top and bottom side etching in area 1 (b) is less than 100nm, the pattern in area 2 (c) is not damaged or detached, and the etching value in area 2 (d) is 0.1<CD value<0.2μm, all of which meet the etching requirements.

[0088] Figure 4 (a) is an OM image of area 1 after being etched using the etching solution of Example 4, (b) is an SEM electron microscope image of area 1 after being etched using the etching solution of Example 4, (c) is an OM image of area 2 after being etched using the etching solution of Example 4, and (d) is an SEM electron microscope image of area 2 after being etched using the etching solution of Example 4; Figure 4 It can be seen that: there are a few black spots and dark spots in area 1 (a), the bottom erosion in area 1 (b) is greater than 100nm, the pattern in area 2 (c) is intact, and the etching value in area 2 (d) is 0.1<CD value<0.2μm, and the etching effect is average.

[0089] Figure 5 (a) is the OM image of area 1 after etching with the etching solution of Example 5, (b) is the SEM electron microscope image of area 1 after etching with the etching solution of Example 5, (c) is the OM image of area 2 after etching with the etching solution of Example 5, and (d) is the SEM electron microscope image of area 2 after etching with the etching solution of Example 5. Figure 5 It can be seen that: there are a few black spots and dark spots in area 1 (a), the top side etching in area 1 (b) is greater than 100nm, the pattern in area 2 (c) is intact, and the etching value in area 2 (d) is 0.1<CD value<0.2μm, and the etching effect is average.

[0090] Figure 6 (a) is the OM image of area 1 after etching with the etching solution of Example 6, (b) is the SEM electron microscope image of area 1 after etching with the etching solution of Example 6, (c) is the OM image of area 2 after etching with the etching solution of Example 6, and (d) is the SEM electron microscope image of area 2 after etching with the etching solution of Example 6. Figure 6 It can be seen that: there are a few black spots and dark spots in area 1 (a), the bottom erosion in area 1 (b) is greater than 100nm, the pattern in area 2 (c) is intact, and the etching value in area 2 (d) is 0.1<CD value<0.2μm, and the etching effect is average.

[0091] Figure 7(a) is the OM image of area 1 after etching with the etching solution of Example 7, (b) is the SEM electron microscope image of area 1 after etching with the etching solution of Example 7, (c) is the OM image of area 2 after etching with the etching solution of Example 7, and (d) is the SEM electron microscope image of area 2 after etching with the etching solution of Example 7. Figure 7 It can be seen that: there are a few black spots and dark spots in area 1 (a), the bottom erosion in area 1 (b) is greater than 100nm, the pattern in area 2 (c) is intact, and the etching value in area 2 (d) is 0.1<CD value<0.2μm, and the etching effect is average.

[0092] Figure 8 (a) is the OM image of area 1 after etching with the etching solution of Comparative Example 1, (b) is the SEM electron microscope image of area 1 after etching with the etching solution of Comparative Example 1, (c) is the OM image of area 2 after etching with the etching solution of Comparative Example 1, and (d) is the SEM electron microscope image of area 2 after etching with the etching solution of Comparative Example 1. Figure 8 It can be seen that there are a large number of black spots and dark spots in area 1 (a), the top side etching in area 1 (b) is greater than 200nm, the pattern in area 2 (c) is incomplete and falling off, and the etching CD value in area 2 (d) is greater than 0.2μm, indicating poor etching effect.

[0093] Figure 9 (a) is the OM image of area 1 after etching with the etching solution of Comparative Example 2, (b) is the SEM electron microscope image of area 1 after etching with the etching solution of Comparative Example 2, (c) is the OM image of area 2 after etching with the etching solution of Comparative Example 2, and (d) is the SEM electron microscope image of area 2 after etching with the etching solution of Comparative Example 2. Figure 9 It can be seen that there are a large number of black spots and dark spots in area 1 (a), the top side etching in area 1 (b) is greater than 200nm, the pattern in area 2 (c) is incomplete and falling off, and the etching CD value in area 2 (d) is greater than 0.2μm, indicating poor etching effect.

[0094] Figure 10 (a) is the OM image of area 1 after etching with the etching solution of Comparative Example 3, (b) is the SEM electron microscope image of area 1 after etching with the etching solution of Comparative Example 3, (c) is the OM image of area 2 after etching with the etching solution of Comparative Example 3, and (d) is the SEM electron microscope image of area 2 after etching with the etching solution of Comparative Example 3. Figure 10 It can be seen that there are a large number of black spots and dark spots in area 1 (a), the top and bottom side etching in area 1 (b) is greater than 300nm, the pattern in area 2 (c) is incomplete and falling off, and the etching CD value in area 2 (d) is greater than 0.3μm, indicating poor etching effect.

[0095] Table 1 Performance test of etching solutions of Examples 1-7 and Comparative Examples 1-3

[0096] ;

[0097] Combined with Table 1 Figure 1-10 It can be seen that the ITO-Ag-ITO etching solutions obtained in Examples 1-7 are significantly better than those in Comparative Examples 1-3.

[0098] Comparing Examples 1, 4, and 5 with Comparative Example 1, it can be seen that the addition of sulfocarboxylic acid to the etching solution of the present invention can reduce the black spots and dark spots in Region 1, improve the side etching of Al, and the silver film layer in Region 2 does not fall off, effectively avoiding overetching of the silver layer. Further comparing Example 1 with Examples 4 and 5, the present invention prefers a mixture of 2-sulfoacetic acid and 4,8-disulfonaphthalene-2,6-dicarboxylic acid as the sulfocarboxylic acid. The synergistic effect of the two can significantly improve the etching phenomenon in Regions 1 and 2. Comparing Example 1 with Examples 6 and 7, it can be seen that the molecular weight of the polyetheramine preferred in the present invention is between 400 and 1000, which helps to reduce the size of the top and bottom layers and greatly reduces the degree of side etching of the Al layer. Comparing Example 1 with Comparative Example 2, it can be seen that the addition of bisulfate to the etching solution of the present invention can prevent overetching of the ITO layer compared to sulfate, thereby better and more effectively regulating the etching rates of ITO and Ag, which helps to avoid the occurrence of undesirable etching phenomena. By comparing Example 1 with Comparative Example 3, it can be seen that the etching solution of the present invention has better performance and can effectively solve the problems of ITO and Ag etching difference, silver residue, silver precipitation and metal Al corrosion existing in existing etching solutions (phosphoric acid, nitric acid, acetic acid system).

[0099] Those skilled in the art will appreciate that the foregoing descriptions are merely specific embodiments of the present invention, and not exhaustive. It should be noted that numerous variations and modifications are possible for those skilled in the art, and all such variations and modifications that do not exceed the scope of the claims should be considered within the scope of protection of the present invention.

Claims

1. An ITO-Ag-ITO etching solution, characterized in that, The invention comprises the following components in percentage by mass: 15-30% tartaric acid, 8-20% sulfocarboxylic acid, 5-15% bisulfate, 3-10% nitric acid, 2-6% sugar alcohol compound, 0.1-5% polyetheramine, 0.01-1% corrosion inhibitor, and the balance is water; the sulfocarboxylic acid is obtained by mixing 2-sulfoacetic acid and 4,8-disulfonaphthalene-2,6-dicarboxylic acid in a mass ratio of (3-7):2, or by mixing 3-sulfopropionic acid and sulfophthalic acid in a mass ratio of 2:1; the molecular weight of the polyetheramine is 400-1000; the sugar alcohol compound is any one of sorbitol, mannitol, xylitol, maltitol, threitol, erythritol, ribitol, fucitol, galactitol, arabitol, and iditol, or a combination of two or more thereof.

2. The ITO-Ag-ITO etching solution according to claim 1, wherein The bisulfate is any one of ammonium bisulfate, sodium bisulfate, and potassium bisulfate, or a combination of two or more thereof.

3. The ITO-Ag-ITO etching solution according to claim 1, wherein The polyetheramine is any one of polyetheramine D400, polyetheramine D600, and polyetheramine D800, or a combination of two or more thereof.

4. The ITO-Ag-ITO etching solution according to claim 1, wherein The corrosion inhibitor is an azole compound; the azole compound is any one of methyl benzotriazole, benzotriazole, and 5-aminotetrazole, or a combination of two or more thereof.

5. A method for preparing the ITO-Ag-ITO etching solution according to any one of claims 1 to 4, characterized in that: The following steps are involved: Weigh the raw materials and mix them evenly in a container, stirring until they are completely dissolved.

6. Use of the ITO-Ag-ITO etching solution according to any one of claims 1 to 4 in etching an indium tin oxide film, a silver film, or an alloy film of an indium tin oxide film and a silver film.

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