Cu-ITO and Cu-MoNb multi-film-layer structure etching liquid composition and preparation method thereof

Abstract

The invention relates to the technical field of etching liquid compositions, in particular to a Cu-ITO and Cu-MoNb multi-film-layer structure etching liquid composition and a preparation method thereof.The Cu-ITO and Cu-MoNb multi-film-layer structure etching liquid composition at least comprises, by mass, 10%-23% of hydrogen peroxide, 0.1%-6.0% of organic acid, 0.1%-8.0% of inorganic acid salt, 0.01%-2.0% of a copper inhibitor, 0.05%-2.5% of an interface inhibitor, 0.05%-1.5% of a fluorine compound, 0.01%-3% of an alkylamine compound and the balance water. According to the method, the steps of simultaneous etching of copper and indium tin oxide films, PR (photoresist dry etching) and copper etching are carried out in a 2W1D mode, the technological process is simplified, the problem of poor technology is effectively solved, meanwhile, the cost is reduced, and mass production and application are easy.

Description

Technical Field

[0001] The present invention relates to the technical field of etching solution compositions, and specifically to an etching solution composition for a Cu-ITO and Cu-MoNb multi-layer film structure and a preparation method thereof. Background Art

[0002] In an etching composition system with a pH of 2 to 3, hydrogen peroxide is generally used as the main oxidant, in combination with inhibitors, chelating agents, and fluorine-based compounds, etc. In order to wire a touch panel, in the Gate process, especially when the lower film uses an indium tin oxide film (ITO) transparent electrode as a common electrode (Vcom), it is necessary to perform wet etching on the multi-layer structure of copper / indium tin oxide (Cu-ITO). The existing method is the 3W1D (three wet etching and one dry etching) method: copper etching → indium tin oxide film etching → PR (photoresist) dry etching → copper etching, which requires a copper etching solution and an indium oxide film etching solution respectively. Since most of the indium oxide film etching solutions are strong acids, it will cause multiple problems of copper wiring damage. Chinese Patent Application (Publication No. CN115821264A) discloses an etching solution composition, although it can etch Cu and ITO simultaneously, but a large amount of fluorine-based compounds are added to the formula, resulting in etching defects during the etching of copper and molybdenum alloy films due to undercut and interfacial corrosion between the alloy films, so it is difficult to be mass-produced and applied. Summary of the Invention

[0003] In order to solve the above problems, the present invention provides an etching solution composition for a Cu-ITO and Cu-MoNb multi-layer film structure and a preparation method thereof, which is carried out in the 2W1D (1st wet etching -> 1st dry etching -> 2nd wet etching) manner: simultaneous etching of copper and indium tin oxide film → PR (photoresist dry etching) → copper etching, which simplifies the process flow, effectively improves the process defect problems and reduces the cost, and is easy to be mass-produced and applied.

[0004] On the one hand, the present invention provides an etching solution composition for a Cu-ITO and Cu-MoNb multi-layer film structure, which, by mass percentage, at least includes: 10 - 23% of hydrogen peroxide, 0.1 - 6.0% of organic acid, 0.1 - 8.0% of inorganic acid salt, 0.01 - 2.0% of copper inhibitor, 0.05 - 2.5% of interface inhibitor, 0.05 - 1.5% of fluorine-based compound, 0.01 - 3% of alkylamine compound, and the balance is made up with water.

[0005] In one embodiment, the etching solution composition for the Cu-ITO and Cu-MoNb multi-layer film structure comprises, by mass percentage, at least: hydrogen peroxide 13-18%, organic acid 0.5-3.0%, inorganic acid salt 2.0-4.0%, copper inhibitor 0.1-0.6%, interface inhibitor 0.08-0.8%, fluorine-based compound 0.05-0.6%, alkylamine compound 0.1-1.0%, and water to make up the balance.

[0006] In one embodiment, the organic acid is selected from one or a combination of two of acetic acid, formic acid, butyric acid, citric acid, glycolic acid, oxalic acid, malonic acid, malic acid, valeric acid, propionic acid, tartaric acid, gluconic acid or succinic acid.

[0007] In one embodiment, the organic acid is citric acid.

[0008] In one embodiment, the inorganic acid salt is selected from at least one of sulfate, nitrate or hydrochloride.

[0009] In one embodiment, the inorganic acid salt is selected from at least one of potassium nitrate, potassium sulfate, potassium chloride, sodium nitrate, sodium sulfate or sodium chloride.

[0010] In one embodiment, the inorganic acid salt is potassium nitrate.

[0011] In one embodiment, the copper inhibitor is selected from at least one of heterocyclic aromatic compounds or heterocyclic aliphatic compounds.

[0012] In one embodiment, the heterocyclic aromatic compounds are selected from at least one of furan, thiophene, pyrrole, oxazole, imidazole, pyrazole, triazole, tetrazole, 5-aminotetrazole or methyltetrazole.

[0013] In one embodiment, the heterocyclic aliphatic compounds are selected from at least one of piperazine, methylpiperazine, hydroxyethylpiperazine, pyrrolidine or alloxan.

[0014] In one embodiment, the copper inhibitor is 5-aminotetrazole.

[0015] In one embodiment, the interface inhibitor is selected from at least one of monoisopropylamine, diisopropylamine, N,N-diethylisopropylamine, N-isopropyl-N-methylamine, N-ethylisopropylamine, isopropyl-(2-pyridin-2-yl-ethyl)amine or N,N-diisopropylethylamine.

[0016] In one embodiment, the interface inhibitor is diisopropylamine.

[0017] In one embodiment, the fluorine-based compound is selected from at least one of HF, NaF, KF, AlF3, HBF4, NH4F, NH4HF2, NaHF2, KHF2 or NH4BF4.

[0018] In one embodiment, the fluorine-based compound is HF (hydrofluoric acid).

[0019] In one embodiment, the alkylamine compound is selected from at least one of butylamine, pentylamine, octylamine, 2-ethyl-1-butylamine, 2-hexylamine, 2-ethyl-hexylamine, 2-ethyl-hexylamine, heptylamine, hexylamine or cyclohexylamine.

[0020] In one embodiment, the alkylamine compound is cyclohexylamine.

[0021] Currently, the 5Mask process is basically used for manufacturing amorphous silicon substrates, that is, five photolithography processes are required. The process is relatively mature and the yield is also relatively stable. However, each photolithography process includes four steps: exposure, development, etching, and stripping. Each step requires the input of materials, labor, and time. If the number of photolithographies can be reduced, the manufacturing cost can be reduced. Thus, the 4Mask process is produced. In the 4Mask process, the semiconductor layer and the source-drain metal layer are made using the same Mask. This process eliminates one Mask production and the corresponding photoresist coating and exposure machine development processes, saving the production cost. However, there are problems of high process requirements and low yield.

[0022] By optimizing the selection, combination, and addition amount control of hydrogen peroxide, organic acid, inorganic acid salt, copper inhibitor, interface inhibitor, fluorine-based compound, and alkylamine compound in the system, the present invention enables the provided etching liquid composition to simultaneously meet the etching requirements of the Cu-ITO and Cu-MoNb multi-layer film structures, and thus can be effectively applied to the 4Mask process. Specifically, in the exploration process of the present invention, it is found that by introducing an interface inhibitor into the etching liquid composition system, especially when the introduced interface inhibitor is diisopropylamine, the problem of poor edge etching caused by the addition of the fluorine-based compound is effectively solved while balancing the etching effect of the etching composition on ITO. Further, by controlling the addition amount of diisopropylamine in the system to be 0.05-0.8%, especially when the addition amount of diisopropylamine in the system is 0.3%, the obtained etching composition has excellent etching effects on both Cu-ITO and Cu-MoNb, with a CD-loss of 0.5-0.65 μm, a Taper angle of 40-50°, no residue, no cracking, no poor edge etching defects, and a maximum copper load of 5000 ppm.

[0023] On the other hand, the present invention provides a method for preparing an etching solution composition for a Cu-ITO and a Cu-MoNb multi-layer film structure, which at least includes the following steps: mixing hydrogen peroxide, organic acid, inorganic acid salt, copper inhibitor, interface inhibitor, fluorine-based compound, alkylamine compound and water by stirring to obtain the etching solution composition for the Cu-ITO and the Cu-MoNb multi-layer film structure.

[0024] The etching solution composition for the Cu-ITO and the Cu-MoNb multi-layer film structure provided by the present invention is convenient to use, has a fast etching rate, good stability, high service life, can effectively reduce costs while improving the process yield.

[0025] Beneficial effects

[0026] 1. The present invention provides an etching solution composition for a Cu-ITO and a Cu-MoNb multi-layer film structure and a preparation method thereof, which are carried out in a 2W1D manner: simultaneous etching of copper and indium tin oxide film → PR (dry etching of photoresist) → copper etching, simplifying the process flow, effectively improving process defects while reducing costs, and being easy for mass production applications.

[0027] 2. By optimizing the selection, coordination and addition amount control of hydrogen peroxide, organic acid, inorganic acid salt, copper inhibitor, interface inhibitor, fluorine-based compound, alkylamine compound in the system, the provided etching solution composition can meet the etching requirements of the Cu-ITO and the Cu-MoNb multi-layer film structure at the same time, and thus can be effectively applied to the 4Mask process.

[0028] 3. During the exploration process of the present invention, it is found that by introducing an interface inhibitor into the etching solution composition system, especially when the introduced interface inhibitor is diisopropylamine, it can effectively solve the problem of edge etching defects caused by the addition of fluorine-based compounds while balancing the etching effect of the etching composition on ITO.

[0029] 4. By controlling the addition amount of diisopropylamine in the system to be 0.05-0.8%, especially when the addition amount of diisopropylamine in the system is 0.3%, the obtained etching composition has excellent etching effects on both Cu-ITO and Cu-MoNb, the CD-loss is 0.5-0.65μm, the Taper angle is 40-50°, there is no residue, no cracking, no edge etching defects, and the highest copper load is 5000ppm.

[0030] 5. The etching solution composition for the Cu-ITO and the Cu-MoNb multi-layer film structure provided by the present invention is convenient to use, has a fast etching rate, good stability, high service life, can effectively reduce costs while improving the process yield. Brief description of the drawings

[0031] Figure 1SEM characterization diagrams after etching Cu / ITO (left) and Cu / MoNb (right) with the etching solution composition provided for Example 1.

[0032] Figure 2 SEM characterization diagrams after etching Cu / ITO (left) and Cu / MoNb (right) with the etching solution composition provided for Comparative Example 1.

[0033] Figure 3 SEM characterization diagrams after etching Cu / ITO (left) and Cu / MoNb (right) with the etching solution composition provided for Comparative Example 2.

[0034] Figure 4 SEM characterization diagrams after etching Cu / ITO (left) and Cu / MoNb (right) with the etching solution composition provided for Comparative Example 3. Detailed Description of the Invention

[0035] Examples 1 - 4, Comparative Examples 1 - 3

[0036] Examples 1 - 4 and Comparative Examples 1 - 3 of the present invention provide an etching solution composition for a Cu - ITO and Cu - MoNb multi - film layer structure. By mass percentage, the formulation is shown in Table 1.

[0037] Table 1

[0038]

[0039]

[0040] Examples 1 - 4 and Comparative Examples 1 - 3 of the present invention also provide a preparation method for an etching solution composition for a Cu - ITO and Cu - MoNb multi - film layer structure, including the following steps: Mix hydrogen peroxide, organic acid, inorganic acid salt, copper inhibitor, interface inhibitor, fluorine - based compound, alkylamine compound and water by stirring to obtain the etching solution composition for a Cu - ITO and Cu - MoNb multi - film layer structure.

[0041] Performance Testing

[0042] 1. Evaluation of etching performance: Etch the Cu / ITO film and Cu / MoNb film using the etching compositions provided in the examples and comparative examples. The etching conditions are shown in Table 2. After etching, use an SEM analysis device to confirm the etching performance. The results are shown in Table 2 and Figures 1-4 .

[0043] 2. Maximum copper ion loading (ppm): Starting from a copper ion concentration of 500 ppm, confirm until there is a change of more than 10% in CD - loss (line - width loss). The results are shown in Table 2.

[0044] Table 2

[0045]

[0046]

[0047] From the data in Table 2 and Figures 1-4 it can be seen that, compared with Comparative Examples 1-3, the etching liquid compositions of the Cu-ITO and Cu-MoNb multi-film layer structures provided by Examples 1-4 are capable of compatibly etching Cu / ITO and Cu / MoNb.

Claims

1. A Cu-ITO and Cu-MoNb multi-film layer structure etching liquid composition, characterized in that, By mass percentage, it at least includes: hydrogen peroxide 10 - 23%, organic acid 0.1 - 6.0%, inorganic acid salt 0.1 - 8.0%, copper inhibitor 0.01 - 2.0%, interface inhibitor 0.05 - 2.5%, fluorine-based compound 0.05 - 1.5%, alkylamine compound 0.01 - 3%, and water to make up the balance.

2. The etching liquid composition for the Cu-ITO and Cu-MoNb multi-film layer structure according to claim 1, wherein The organic acid is selected from one or a combination of two of acetic acid, formic acid, butyric acid, citric acid, glycolic acid, oxalic acid, malonic acid, malic acid, valeric acid, propionic acid, tartaric acid, gluconic acid, or succinic acid.

3. The etching liquid composition for the Cu-ITO and Cu-MoNb multi-film layer structure according to claim 1, wherein The inorganic acid salt is selected from at least one of sulfate, nitrate, or hydrochloride.

4. The Cu-ITO and Cu-MoNb multi-layer film structure etching solution composition according to claim 3, characterized in that, The inorganic acid salt is selected from at least one of potassium nitrate, potassium sulfate, potassium chloride, sodium nitrate, sodium sulfate, or sodium chloride.

5. The etching liquid composition for the Cu-ITO and Cu-MoNb multi-film layer structure according to claim 1, characterized in that, The copper inhibitor is selected from at least one of heterocyclic aromatic compounds or heterocyclic aliphatic compounds.

6. The Cu-ITO and Cu-MoNb multi-film layer structure etching liquid composition according to claim 5, characterized in that, The heterocyclic aromatic compound is selected from at least one of furan, thiophene, pyrrole, oxazole, imidazole, pyrazole, triazole, tetrazole, 5 - aminotetrazole, or methyltetrazole.

7. The etching liquid composition for the Cu-ITO and Cu-MoNb multi-film layer structure according to claim 5, wherein The heterocyclic aliphatic compound is selected from at least one of piperazine, methylpiperazine, hydroxyethylpiperazine, pyrrolidine, or alloxan.

8. The etching liquid composition for the Cu-ITO and Cu-MoNb multi-layer film structure according to claim 1, characterized in that, The interface inhibitor is selected from at least one of monoisopropylamine, diisopropylamine, N,N - diethylisopropylamine, N - isopropyl - N - methylamine, N - ethylisopropylamine, isopropyl-(2 - pyridin - 2 - yl - ethyl)amine, or N,N - diisopropylethylamine.

9. The etching liquid composition for the Cu-ITO and Cu-MoNb multi-film layer structure according to claim 1, characterized in that, The alkylamine compound is selected from at least one of butylamine, pentylamine, octylamine, 2 - ethyl - 1 - butylamine, 2 - hexylamine, 2 - ethyl - hexylamine, 2 - ethyl - hexylamine, heptylamine, hexylamine, or cyclohexylamine.

10. A preparation method of an etching solution composition for a Cu-ITO and Cu-MoNb multi-film layer structure according to any one of claims 1-9, characterized in that, It at least includes the following steps: After stirring and mixing hydrogen peroxide, organic acid, inorganic acid salt, copper inhibitor, interface inhibitor, fluorine-based compound, alkylamine compound, and water, the Cu-ITO and Cu-MoNb multi-layer structure etching solution composition is obtained.

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