Metal etching liquid

Abstract

The invention belongs to the technical field of metal etching, and particularly discloses a metal etching solution which comprises the following components in percentage by mass: 50-60% of phosphoric acid, 0.5-1.5% of nitric acid, 6-10% of acetic acid, 3-6% of a sulfonic acid compound, 2.5-3.6% of inorganic salt, 0.5-1.5% of an organic chelating agent, 1-3% of a nonionic surfactant, 0.1-2% of an amido carbazole compound and the balance of deionized water. The metal etching liquid provided by the invention is small in CD bias, high in etching speed and good in angle stability when being used for etching aluminum, and is free of residues and high in etching speed when being used for etching copper, and does not damage a substrate.

Description

Technical Field

[0001] The invention belongs to the technical field of metal etching, and in particular relates to a metal etching liquid. Background Art

[0002] Metal etching liquid removes or changes specific parts of the metal surface through chemical reactions to form the desired tiny structures or patterns. With the rapid development of high-tech industries such as semiconductors and microelectronics, the demand for metal etching liquid is growing, and its performance and quality also directly affect the yield and reliability of the product.

[0003] When etching copper substrates, existing copper etching solutions will etch glass substrates due to the presence of fluoride ions, causing the surface of the glass substrate to be uneven, which in turn affects the hardness of the glass substrate. In addition, when treating the waste liquid, the treatment is difficult and costly, which will have an impact on the environment and its own benefits.

[0004] At present, the aluminum etching solution commonly used in the production line does not contain fluoride ions, and is low in cost and easy to recycle. Considering multiple uses of one dose, the existing aluminum etching solution is used to treat the copper substrate, such as the invention patent CN110129797 A discloses a molybdenum-aluminum-molybdenum compatible etching solution, which includes the following components in mass percentage: 60-75% phosphoric acid, 1-10% nitric acid, 5-15% acetic acid, 1-2% potassium dihydrogen phosphate, 1-2% dipotassium hydrogen phosphate, and 10-20% pure water; the etching solution can avoid damage to the glass substrate, but a large amount of residue often appears on the copper surface, and the etching speed is too slow to achieve the ideal etching effect. Summary of the invention

[0005] The object of the present invention is to overcome the above problems existing in the prior art and provide a metal etching solution, which has a small CD bias, a fast etching speed, and good angle stability when etching aluminum, and has no residue when etching copper, a fast etching speed, and does not damage the substrate.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0007] A metal etching solution comprises the following components, measured by mass percentage: 50-60% phosphoric acid, 0.5-1.5% nitric acid, 6-10% acetic acid, 3-6% sulfonic acid compound, 2.5-3.6% inorganic salt, 0.5-1.5% organic chelating agent, 1-3% nonionic surfactant, 0.1-2% amide carbazole compound, and the balance is deionized water;

[0008] The chemical structure of the amidocarbazole compound is shown in formula (I):

[0009]

[0010] Furthermore, the sulfonic acid compound is any one or more of methanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, aminomethanesulfonic acid, aminosulfonic acid, naphthalenesulfonic acid, isethionic acid, and 3-hydroxypropanesulfonic acid mixed in any proportion.

[0011] Furthermore, the inorganic salt is any one or more of potassium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium nitrate, ammonium dihydrogen phosphate, trisodium phosphate, trisodium citrate, and potassium acetate mixed in any proportion.

[0012] Furthermore, the organic chelating agent is any one or more of sodium dimethyldithiocarbamate, trisodium ethylenediamine disuccinate, disodium ethylenediaminetetraacetate, trisodium methylglycine diacetate, and tetrasodium glutamate diacetate, mixed in any proportion.

[0013] Furthermore, the nonionic surfactant is any one or more of polyethylene glycol ether, polyoxyethylene polyoxypropylene alkyl ether, polyethylene glycol sulfate, and polyoxyethylene ethyl ether mixed in any proportion.

[0014] Furthermore, the preparation method of the amidocarbazole compound comprises the following steps:

[0015] S1. Add 3,6-dichlorocarbazole and acetic anhydride to acetic acid, stir evenly, heat to 60-90°C, slowly drop nitric acid, complete the dropwise addition within 10-30 seconds, stir to react for 4-8 hours, add water, separate the organic layer, and dry to obtain compound A;

[0016] S2. Under nitrogen environment, add compound A and palladium carbon catalyst to ethanol, stir evenly, heat to 70-80°C, slowly drop hydrazine hydrate, complete the dropwise addition within 10-30s, stir to react for 20-30h, filter while hot to obtain a filtrate after the reaction is completed, cool the filtrate to room temperature, then cool in ice water for 10-30min, precipitate solid, filter with suction, wash, and dry to obtain compound B;

[0017] S3. Dissolve compound B and triethylamine in tetrahydrofuran, stir evenly, slowly add benzoyl chloride dropwise within 10-30 seconds, reflux at 70-80°C for 10-15 hours, add water and stir for 30 minutes, separate the organic layer, dehydrate the organic layer with magnesium sulfate, filter and evaporate under reduced pressure to obtain an amide carbazole compound.

[0018] Furthermore, the reaction formula of the preparation method of the amidocarbazole compound is as follows:

[0019]

[0020] Furthermore, in step S1, the ratio of the amount of 3,6-dichlorocarbazole, nitric acid, acetic anhydride and acetic acid is (0.23-0.25) g: (0.12-0.14) g: 0.05 g: 50 mL.

[0021] Furthermore, in step S2, the ratio of the amount of the compound A, the palladium-carbon catalyst, the hydrazine hydrate, and the ethanol is (0.32-0.35) g:0.02 g:(0.10-0.11) g:50 mL;

[0022] In the palladium-carbon catalyst, the loading amount of metal palladium is 10%.

[0023] Furthermore, in step S3, the ratio of the amount of compound B, benzoyl chloride, triethylamine and tetrahydrofuran is (0.26-0.27) g: (0.28-0.29) g: 0.05 g: 50 mL.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The metal etching solution provided by the present invention contains a sulfonic acid compound in its formula. The sulfonic acid compound mainly provides oxidizing property for the etching solution. When phosphoric acid and nitric acid are used to etch the copper film, the etching performance is hindered because nitric acid is easily decomposed, while the sulfonic acid compound can reduce the decomposition rate of nitric acid and stably maintain the etching rate of the copper film. The content of the sulfonic acid compound is maintained at 3-6%. When the content is greater than 6%, the etching rate of the copper film may be too fast, which may induce poor corrosion, cause uneven etching, and then cause the surface residue of the metal copper; when the content is less than 3%, the stability of nitric acid may be hindered due to the reduced inhibitory effect on the decomposition of nitric acid, thereby causing the generation of residue.

[0026] 2. The nonionic surfactant in the metal etching solution provided by the present invention can increase the wettability of the etching solution, improve the contact area between the etching solution and the metal copper, accelerate the penetration of the etching solution and the dissolution of the metal copper, and improve the uniformity of the etching speed, so that the surface of the metal copper is clean and free of residue.

[0027] 3. The metal etching solution provided by the present invention has an amide carbazole compound in its formula containing four benzene rings, and the π-π conjugated bond can be stably adsorbed on the surface of the copper film; at the same time, the amide group introduced on the carbazole can increase its polarity, form a stable complex with copper ions during the etching process, form a uniform film on the surface of the copper film, and improve the uniformity of etching. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1 This is an etching effect diagram of the aluminum substrate of Example 1 in the performance test of the present invention;

[0030] Figure 2 This is an etching effect diagram of the aluminum substrate of Comparative Example 1 in the performance test of the present invention;

[0031] Figure 3 This is a copper substrate etching effect diagram of Example 1 in the performance test of the present invention;

[0032] Figure 4 This is a copper substrate etching effect diagram of comparative example 1 in the performance test of the present invention;

[0033] Figure 5 This is a copper substrate etching effect diagram of comparative example 4 in the performance test of the present invention;

[0034] Figure 6 This is a copper substrate etching effect diagram of comparative example 5 in the performance test of the present invention;

[0035] Figure 7 This is a copper substrate etching effect diagram of comparative example 6 in the performance test of the present invention;

[0036] Figure 8 This is a diagram of the copper substrate etching effect of comparative example 7 in the performance test of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Preparation Example 1

[0039] This preparation example provides a method for preparing an amide carbazole compound, which is prepared by the following method:

[0040] S1. Add 0.23 g 3,6-dichlorocarbazole and 0.05 g acetic anhydride to 50 mL acetic acid, stir evenly, heat to 60°C, slowly drop 0.12 g nitric acid, complete the dropwise addition within 10 seconds, stir and react for 4 hours, add 50 mL water, separate the organic layer, and dry to obtain compound A;

[0041] S2. Under nitrogen environment, add 0.32g of compound A and 0.02g of 10wt% palladium carbon catalyst to 50mL of ethanol, stir evenly, heat to 70°C, slowly drop 0.10g of hydrazine hydrate, after the dropwise addition is completed within 10s, stir and react for 20h, filter while hot to obtain a filtrate after the reaction is completed; cool the filtrate to room temperature, then place in ice water to cool for 10min, precipitate solid, filter with suction, wash, and dry to obtain compound B;

[0042] S3. Dissolve 0.26 g of compound B and 0.05 g of triethylamine in 50 mL of tetrahydrofuran, stir evenly, slowly drop 0.28 g of benzoyl chloride, and after the dropwise addition is completed within 10 s, reflux at 70 °C for 10 h, add 50 mL of water and stir for 30 min, separate the organic layer, dehydrate the organic layer with magnesium sulfate, filter and evaporate under reduced pressure to obtain an amide carbazole compound.

[0043] Preparation Example 2

[0044] This preparation example provides a method for preparing an amide carbazole compound, which is prepared by the following method:

[0045] S1. Add 0.24 g 3,6-dichlorocarbazole and 0.05 g acetic anhydride to 50 mL acetic acid, stir evenly, heat to 70°C, slowly drop 0.13 g nitric acid, complete the dropwise addition within 20 seconds, stir and react for 6 hours, add 50 mL water, separate the organic layer, and dry to obtain compound A;

[0046] S2. Under nitrogen environment, add 0.33g of compound A and 0.02g of 10wt% palladium carbon catalyst to 50mL of ethanol, stir evenly, heat to 75°C, slowly drop 0.10g of hydrazine hydrate, after the dropwise addition is completed within 20s, stir and react for 25h, filter while hot to obtain a filtrate after the reaction is completed; cool the filtrate to room temperature, then cool in ice water for 20min, precipitate a solid, filter with suction, wash, and dry to obtain compound B;

[0047] S3. Dissolve 0.26 g of compound B and 0.05 g of triethylamine in 50 mL of tetrahydrofuran, stir evenly, slowly add 0.29 g of benzoyl chloride dropwise within 20 s, reflux at 75 °C for 13 h, add 50 mL of water and stir for 30 min, separate the organic layer, dehydrate the organic layer with magnesium sulfate, filter and evaporate under reduced pressure to obtain an amide carbazole compound.

[0048] Preparation Example 3

[0049] This preparation example provides a method for preparing an amide carbazole compound, which is prepared by the following method:

[0050] S1. Add 0.25 g 3,6-dichlorocarbazole and 0.05 g acetic anhydride to 50 mL acetic acid, stir evenly, heat to 90°C, slowly drop 0.14 g nitric acid, complete the dropwise addition within 30 seconds, stir and react for 8 hours, add 50 mL water, separate the organic layer, and dry to obtain compound A;

[0051] S2. Under nitrogen environment, add 0.35g of compound A and 0.02g of 10wt% palladium carbon catalyst to 50mL of ethanol, stir evenly, heat to 80°C, slowly drop 0.11g of hydrazine hydrate, and after the dropwise addition is completed within 30s, stir and react for 30h. After the reaction is completed, filter while hot to obtain a filtrate; cool the filtrate to room temperature, then cool in ice water for 30min, precipitate a solid, filter with suction, wash, and dry to obtain compound B;

[0052] S3. Dissolve 0.27 g of compound B and 0.05 g of triethylamine in 50 mL of tetrahydrofuran, stir evenly, slowly drop 0.29 g of benzoyl chloride, and complete the dropwise addition within 30 s. Reflux at 80 °C for 15 h, add 50 mL of water and stir for 30 min, separate the organic layer, dehydrate the organic layer with magnesium sulfate, filter and evaporate under reduced pressure to obtain an amide carbazole compound.

[0053] The following are specific examples.

[0054] Example 1

[0055] The present embodiment provides a metal etching solution, which includes the following components by mass percentage: 50% phosphoric acid, 1% nitric acid, 8% acetic acid, 5% methylsulfonic acid, 2.5% trisodium phosphate, 1% sodium dimethyl dithiocarbamate, 1% polyethylene glycol ether, 0.5% amide carbazole compound, and the balance is deionized water;

[0056] The amidocarbazole compound is prepared in Preparation Example 1.

[0057] Example 2

[0058] The present embodiment provides a metal etching solution, which includes the following components, measured by mass percentage: 55% phosphoric acid, 0.5% nitric acid, 6% acetic acid, 3% p-toluenesulfonic acid, 2.5% potassium dihydrogen phosphate, 0.5% sodium dimethyldithiocarbamate, 1% polyethylene glycol ether, 0.1% amide carbazole compound, and the balance is deionized water;

[0059] The amidocarbazole compound is prepared in Preparation Example 1.

[0060] Example 3

[0061] The present embodiment provides a metal etching solution, which includes the following components by mass percentage: 58% phosphoric acid, 1.5% nitric acid, 7% acetic acid, 6% aminomethanesulfonic acid, 3% trisodium citrate, 1.5% disodium ethylenediaminetetraacetic acid, 3% polyoxyethylene ethyl ether, 0.8% amide carbazole compound, and the balance is deionized water;

[0062] The amidocarbazole compound is prepared in Preparation Example 2.

[0063] Example 4

[0064] The present embodiment provides a metal etching solution, which includes the following components by mass percentage: 60% phosphoric acid, 1% nitric acid, 10% acetic acid, 4% hydroxyethyl sulfonic acid, 3% diammonium phosphate, 1.4% tetrasodium glutamate diacetate, 2% polyoxyethylene ethyl ether, 1.5% amide carbazole compound, and the balance is deionized water;

[0065] The amide carbazole compound is prepared in Preparation Example 3.

[0066] Example 5

[0067] The present embodiment provides a metal etching solution, which includes the following components, measured by mass percentage: 56% phosphoric acid, 0.7% nitric acid, 10% acetic acid, 6% methanesulfonic acid, 3.6% potassium nitrate, 0.5% disodium ethylenediaminetetraacetate, 1% polyethylene glycol sulfate, 2% amide carbazole compound, and the balance is deionized water;

[0068] The amidocarbazole compound is prepared in Preparation Example 1.

[0069] Example 6

[0070] This embodiment provides a metal etching solution, which is different from the embodiment 1 only in that, in this embodiment, the mass percentage of methanesulfonic acid is 3%, specifically as follows:

[0071] The present embodiment provides a metal etching solution, which includes the following components by mass percentage: 50% phosphoric acid, 1% nitric acid, 8% acetic acid, 3% methylsulfonic acid, 2.5% trisodium phosphate, 1% sodium dimethyl dithiocarbamate, 1% polyethylene glycol ether, 0.5% amide carbazole compound, and the balance is deionized water;

[0072] The amidocarbazole compound is prepared in Preparation Example 1.

[0073] Example 7

[0074] This embodiment provides a metal etching solution, which is different from the embodiment 1 only in that the mass percentage of methanesulfonic acid is 6%, specifically as follows:

[0075] The present embodiment provides a metal etching solution, which includes the following components by mass percentage: 50% phosphoric acid, 1% nitric acid, 8% acetic acid, 6% methylsulfonic acid, 2.5% trisodium phosphate, 1% sodium dimethyl dithiocarbamate, 1% polyethylene glycol ether, 0.5% amide carbazole compound, and the balance is deionized water;

[0076] The amidocarbazole compound is prepared in Preparation Example 1.

[0077] Comparative Example 1

[0078] This comparative example provides a metal etching solution, which is different from Example 1 only in that, in this comparative example, no methanesulfonic acid is added, that is, no sulfonic acid compound is added, specifically as follows:

[0079] This comparative example provides a metal etching solution, which includes the following components, measured by mass percentage: 50% phosphoric acid, 1% nitric acid, 8% acetic acid, 2.5% trisodium phosphate, 1% sodium dimethyl dithiocarbamate, 1% polyethylene glycol ether, 0.5% amide carbazole compound, and the balance is deionized water;

[0080] The amidocarbazole compound is prepared in Preparation Example 1.

[0081] Comparative Example 2

[0082] This comparative example provides a metal etching solution, which is different from Example 1 only in that, in this comparative example, the mass percentage of methanesulfonic acid is 0.5%, specifically as follows:

[0083] The present comparative example provides a metal etching solution, which comprises the following components, measured by mass percentage: 50% phosphoric acid, 1% nitric acid, 8% acetic acid, 0.5% methylsulfonic acid, 2.5% trisodium phosphate, 1% sodium dimethyldithiocarbamate, 1% polyethylene glycol ether, 0.5% amide carbazole compound, and the balance is deionized water;

[0084] The amidocarbazole compound is prepared in Preparation Example 1.

[0085] Comparative Example 3

[0086] This comparative example provides a metal etching solution, which is different from Example 1 only in that, in this comparative example, the mass percentage of methanesulfonic acid is 15%, specifically as follows:

[0087] The comparative example provides a metal etching solution, which comprises the following components by mass percentage: 50% phosphoric acid, 1% nitric acid, 8% acetic acid, 15% methylsulfonic acid, 2.5% trisodium phosphate, 1% sodium dimethyl dithiocarbamate, 1% polyethylene glycol ether, 0.5% amide carbazole compound, and the balance is deionized water;

[0088] The amidocarbazole compound is prepared in Preparation Example 1.

[0089] Comparative Example 4

[0090] This comparative example provides a metal etching solution, which is different from Example 1 only in that no nonionic surfactant is added in this comparative example, and is specifically as follows:

[0091] The comparative example provides a metal etching solution, which comprises the following components by mass percentage: 50% phosphoric acid, 1% nitric acid, 8% acetic acid, 5% methanesulfonic acid, 2.5% trisodium phosphate, 1% sodium dimethyldithiocarbamate, 0.5% amide carbazole compound, and the balance is deionized water;

[0092] The amidocarbazole compound is prepared in Preparation Example 1.

[0093] Comparative Example 5

[0094] This comparative example provides a metal etching solution, which is different from Example 1 only in that no amidocarbazole compound is added in this comparative example, and is specifically as follows:

[0095] The comparative example provides a metal etching solution, which comprises the following components by mass percentage: 50% phosphoric acid, 1% nitric acid, 8% acetic acid, 5% methylsulfonic acid, 2.5% trisodium phosphate, 1% sodium dimethyldithiocarbamate, 1% polyethylene glycol ether, and the balance is deionized water.

[0096] Comparative Example 6

[0097] This comparative example provides a metal etching solution, which is different from Example 1 only in that, in this comparative example, an equal mass of carbazole is used to replace amide carbazole, specifically as follows:

[0098] The comparative example provides a metal etching solution, which comprises the following components by mass percentage: 50% phosphoric acid, 1% nitric acid, 8% acetic acid, 5% methylsulfonic acid, 2.5% trisodium phosphate, 1% sodium dimethyldithiocarbamate, 1% polyethylene glycol ether, 0.5% carbazole, and the balance is deionized water.

[0099] Comparative Example 7

[0100] This comparative example provides a metal etching solution, which includes the following components by mass percentage: 60% phosphoric acid, 5% nitric acid, 5% acetic acid, 1% potassium dihydrogen phosphate, 1% dipotassium hydrogen phosphate, and the balance is deionized water.

[0101] Performance Testing

[0102] The metal etching solutions provided in the above embodiments and comparative examples were subjected to etching experiments to study their etching performance. The specific method was as follows: 2 groups of 100 mL of the above metal etching solutions were prepared respectively, and then placed in a 40° C. water bath for standby use; one group of metal etching solutions was used to etch an aluminum substrate, and the EPD was monitored. The total etching time was 1.4 EPD, and the side etching amount was measured by SEM; the other group of metal etching solutions was used to etch a copper substrate, and the substrate became transparent EPD was monitored. The plane residue was observed by SEM. The specific experimental results are shown in Table 1.

[0103] Table 1

[0104]

[0105]

[0106] The etching effect diagram of the aluminum substrate of Example 1 and Comparative Example 1 is as follows: Figure 1-2 shown.

[0107] The copper substrate etching effect diagrams of Example 1, Comparative Example 1, and Comparative Examples 4-7 are shown as follows: Figure 3-8 shown.

[0108] From Table 1 and Figure 1-8 It can be seen that the metal etching solution obtained in Examples 1-7 can not only maintain the advantages of small CD bias, fast etching speed and good angle stability when etching the aluminum substrate, but also has no residue when etching the copper substrate, has a fast etching speed, does not damage the glass substrate, and can achieve the function of one dose for multiple purposes.

[0109] Comparing Example 1 with Comparative Example 1, it can be seen that the addition of sulfonic acid compounds to the etching solution helps to increase the etching rate and reduce the etching residue of the copper substrate; further comparing Examples 1, 6, and 7 with Comparative Examples 2 and 3, it can be seen that controlling the mass fraction of the sulfonic acid compound within a certain range is more conducive to ensuring uniform etching rate and no residue on the copper surface. Comparing Example 1 with Comparative Example 4, it can be seen that the addition of nonionic surfactants to the etching solution can ensure that there is no residue on the surface of metallic copper. Comparing Example 1 with Comparative Examples 5 and 6, it can be seen that the addition of amide carbazole compounds to the etching solution greatly improves the etching residue on the surface of metallic copper. Comparing Example 1 with Comparative Example 7, it can be seen that the etching solution of the present invention can not only effectively etch aluminum substrates, but also solve the residue problem on the copper surface.

[0110] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0111] The above shows and describes 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 to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A metal etching solution, characterized in that: The composition comprises the following components in terms of mass percentage: 50-60% phosphoric acid, 0.5-1.5% nitric acid, 6-10% acetic acid, 3-6% sulfonic acid compound, 2.5-3.6% inorganic salt, 0.5-1.5% organic chelating agent, 1-3% nonionic surfactant, 0.1-2% amide carbazole compound, and the balance is deionized water; The chemical structure of the amidocarbazole compound is shown in formula (I):

2. A metal etching solution according to claim 1, characterized in that: The sulfonic acid compound is any one or more of methanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, aminomethanesulfonic acid, aminosulfonic acid, naphthalenesulfonic acid, isethionic acid, and 3-hydroxypropanesulfonic acid, mixed in any proportion.

3. A metal etching solution according to claim 1, characterized in that: The inorganic salt is any one or more of potassium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium nitrate, ammonium dihydrogen phosphate, trisodium phosphate, trisodium citrate, and potassium acetate, mixed in any proportion.

4. A metal etching solution according to claim 1, characterized in that: The organic chelating agent is any one or more of sodium dimethyldithiocarbamate, trisodium ethylenediamine disuccinate, disodium ethylenediaminetetraacetate, trisodium methylglycine diacetate, and tetrasodium glutamate diacetate, mixed in any proportion.

5. A metal etching solution according to claim 1, characterized in that: The nonionic surfactant is any one or more of polyethylene glycol ether, polyoxyethylene polyoxypropylene alkyl ether, polyethylene glycol sulfate, and polyoxyethylene ethyl ether mixed in any proportion.

6. A metal etching solution according to claim 1, characterized in that: The preparation method of the amidocarbazole compound comprises the following steps: S1. Add 3,6-dichlorocarbazole and acetic anhydride to acetic acid, stir evenly, heat to 60-90°C, slowly drop nitric acid, complete the dropwise addition within 10-30 seconds, stir to react for 4-8 hours, add water, separate the organic layer, and dry to obtain compound A; S2. Under nitrogen environment, add compound A and palladium carbon catalyst to ethanol, stir evenly, heat to 70-80°C, slowly drop hydrazine hydrate, complete the dropwise addition within 10-30s, stir to react for 20-30h, filter while hot to obtain a filtrate after the reaction is completed, cool the filtrate to room temperature, then cool in ice water for 10-30min, precipitate solid, filter with suction, wash, and dry to obtain compound B; S3. Dissolve compound B and triethylamine in tetrahydrofuran, stir evenly, slowly add benzoyl chloride dropwise within 10-30 seconds, reflux at 70-80°C for 10-15 hours, add water and stir for 30 minutes, separate the organic layer, dehydrate the organic layer with magnesium sulfate, filter and evaporate under reduced pressure to obtain an amide carbazole compound.

7. A metal etching solution according to claim 6, characterized in that: The reaction formula of the preparation method of the amidocarbazole compound is as follows:

8. A metal etching solution according to claim 6, characterized in that: In step S1, the ratio of the amount of 3,6-dichlorocarbazole, nitric acid, acetic anhydride and acetic acid is (0.23-0.25) g: (0.12-0.14) g: 0.05 g: 50 mL.

9. A metal etching solution according to claim 6, characterized in that: In step S2, the ratio of the amount of compound A, palladium-carbon catalyst, hydrazine hydrate and ethanol is (0.32-0.35) g:0.02 g:(0.10-0.11) g:50 mL; In the palladium-carbon catalyst, the loading amount of metal palladium is 10%.

10. A metal etching solution according to claim 6, characterized in that: In step S3, the ratio of the amount of compound B, benzoyl chloride, triethylamine and tetrahydrofuran is (0.26-0.27) g: (0.28-0.29) g: 0.05 g: 50 mL.

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