A low-side-etching, high-precision two-component copper etching solution and its preparation method

Abstract

This invention provides a low-side-etching, high-precision two-component copper etching solution, comprising component A and component B. Component A contains the following components in parts by weight: 8-15 parts hydrogen peroxide, 0.5-3 parts PEG-b-PAA, 0.3-0.8 parts sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles, 0.1-1 parts imidazoline betaine, 1-5 parts organic carboxylic acid, 2-8 parts sulfuric acid or phosphoric acid, and 67-88 parts deionized water. Component B contains the following components in parts by weight: 1-4 parts poly(N-isopropylacrylamide-co-vinylimidazolium), 0.3-1 part Cu-EDTA chelate, 0.5-1 part glycine, 10-25 parts organic acid, 10-20 parts organic base, 0.05-0.5 parts auxiliary corrosion inhibitor, and 45-78 parts deionized water. This invention yields a low-side-etching, high-precision, long-life, and environmentally friendly etching solution.

Description

Technical Field

[0001] This invention relates to the field of copper etching solution technology, specifically to a low-side etching, high-precision two-component copper etching solution and its preparation method. Background Technology

[0002] Thin-film transistor liquid crystal displays (TFT-LCDs), as the mainstream flat panel display technology, are widely used in televisions, computer monitors, smartphones, tablets, and automotive displays. Copper (Cu), due to its extremely low resistivity (approximately 1.7 μΩ·cm), excellent anti-electromigration properties, and good ductility, has become an ideal replacement material for metal wiring in TFT-LCD array substrates. Using copper wiring can significantly reduce signal transmission delay, decrease linewidth, and enable narrow bezel designs, while also reducing power consumption, making it one of the key paths for upgrading TFT-LCD technology.

[0003] The gate linewidth of a TFT-LCD array substrate directly affects the channel length and device performance of the TFT, while the source and drain electrode dimensions are related to the pixel aperture ratio and display uniformity. Taking a 55-inch TV panel with 4K resolution as an example, the size of a single sub-pixel is only about 30μm, and the gate linewidth is usually required to be controlled within 3~5μm or even finer. The lateral etching amount during the copper etching process must be strictly limited to below 0.5μm, otherwise it will lead to linewidth deviation, TFT characteristic drift, and display defects.

[0004] To prevent copper from diffusing into the glass substrate or silicon layer, TFT-LCD copper wiring typically employs a copper / barrier layer dual-layer structure (such as Cu / MoNb, Cu / Ti). Ideally, the copper etchant should have a high etching rate for the copper layer and high selectivity (i.e., a low etching rate) for the barrier layer to achieve complete removal of the copper layer while preserving the barrier layer, ensuring interface quality for subsequent processes. However, the etching potential difference between copper and the barrier layer is significant, making it difficult for traditional etchants to simultaneously address both.

[0005] The H2O2 / H2SO4 system is currently the most environmentally friendly etching solution in TFT-LCD copper manufacturing processes, with the reaction product being only Cu. 2 + Copper can be recovered via electrolysis or chemical precipitation using H2O, and sulfuric acid can be recycled. However, this system has the following prominent problems in practical applications of TFT-LCDs: TFT-LCD etching equipment is usually spray or immersion type, with etching temperatures between 30 and 50°C, and Cu... 2+It has a strong catalytic effect on the decomposition of H2O2. The concentration of H2O2 in the etching bath can drop from its initial value to less than half within hours, causing drastic fluctuations in the etching rate, poor batch-to-batch consistency, and severely affecting the yield of the array substrate. The H2O2 / H2SO4 system itself is isotropic etching, and copper undergoes severe lateral etching while dissolving vertically. For fine gates of TFT-LCDs (linewidth ≤ 5μm), the lateral etching depth often exceeds 1μm, resulting in an actual linewidth much smaller than the design value, TFT threshold voltage drift, and deterioration of display uniformity. TFT-LCD production lines are continuous operations, and the Cu in the etching bath solution... 2+ The concentration accumulates rapidly over time (up to 30-50 g / L). Under high copper loading, H2O2 decomposition intensifies, the etching rate decreases, and Cu... 2+ The adsorption of H2O2 on the copper surface forms an uneven diffusion layer, causing the etching profile to deteriorate. The strong oxidizing property of H2O2 can easily lead to excessive oxidation of the copper surface, forming a rough CuO / Cu2O layer, which affects the quality of subsequent barrier layer etching and insulating layer deposition.

[0006] Currently, some studies use organic acids such as citric acid and malic acid to replace part of the sulfuric acid in order to improve the copper ion complexation ability and etching uniformity. However, organic acids have poor compatibility with H2O2 and are prone to oxidative degradation at high temperatures; moreover, the complexation ability of organic acids for copper is limited, and the etching solution life is still not ideal under high copper load.

[0007] To address the significant shortcomings of etching solutions in terms of stability, lateral etching control, and surface quality, a novel two-component etching solution specifically designed for copper fabrication processes on TFT-LCD array substrates needs to be developed. Summary of the Invention

[0008] Technical problem to be solved: Based on the special requirements of existing TFT-LCD copper manufacturing processes and the shortcomings of existing technologies, this invention proposes a two-component copper etching solution with low side etching and high precision.

[0009] Technical solution: A low-side-etching, high-precision two-component copper etching solution, comprising component A and component B, wherein component A comprises the following components in parts by weight: 8-15 parts hydrogen peroxide PEG-b-PAA 0.5~3 parts Sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles, 0.3~0.8 parts 0.1 to 1 part imidazolinyl betaine 1-5 parts of organic carboxylic acids 2-8 parts sulfuric acid or phosphoric acid 67-88 parts deionized water; Agent B contains the following components in parts by weight: 1-4 parts of poly(N-isopropylacrylamide-co-vinylimidazolium) 0.3-1 part of Cu-EDTA chelate Glycine 0.5-1 part 10-25 parts organic acids 10-20 parts of organic base 0.05~0.5 parts of auxiliary corrosion inhibitor 45-78 parts of deionized water.

[0010] Preferably, the molecular weight of PEG-b-PAA in agent A is 5000~20000 Da; Imidazolinyl betaine is any one of dodecyl imidazolinyl betaine, hydroxyethyl oleic acid imidazolinyl betaine, or lauryl imidazolinyl betaine; The organic acid is either citric acid or tartaric acid.

[0011] Preferably, the molecular weight of poly(N-isopropylacrylamide-co-vinylimidazole) in agent B is 8000~15000 Da; The organic acid is either methanesulfonic acid or acetic acid; The organic base is either tetramethylammonium hydroxide or monoethanolamine; The auxiliary corrosion inhibitor is any one or a combination of benzotriazole, methylbenzotriazole, 1-hydroxybenzotriazole, and N-butylbenzotriazole.

[0012] Preferably, the method for preparing the Cu-EDTA chelate includes the following steps: Weigh out disodium ethylenediaminetetraacetate and dissolve it in deionized water. Adjust the pH to 4.5–5.0, heat to 60°C, and stir to obtain a 0.3 mol / L colorless and transparent solution A. Weigh out copper sulfate pentahydrate and dissolve it in deionized water to obtain a 1 mol / L blue solution B; Solution B was slowly added dropwise to solution A with stirring, maintaining the pH at 4.5–5.5. After the addition was complete, stirring was continued for 30–60 min. Then, the solution was concentrated to about 1 / 3 of its volume by rotary evaporation at 60–70 °C. The solution was cooled to 4 °C and allowed to stand for 12–24 h to precipitate dark blue columnar crystals. The crystals were filtered, washed with cold water, and dried under vacuum to obtain Cu-EDTA chelate.

[0013] Preferably, the preparation method of the sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles includes the following steps: S1. Disperse zinc nitrate hexahydrate and 2-methylimidazole separately in methanol, then add the zinc nitrate solution to the 2-methylimidazole solution, let stand for aging for 12-24 hours, filter and dry to obtain ZIF-8 powder; S2. Place ZIF-8 in a tube furnace, introduce high-purity nitrogen gas for high-temperature calcination, raise the temperature to 800~1000℃ at 2~5℃ / min, and hold for 2~4h to obtain N-doped carbonized ZIF-derived carbon. S3. After cooling, the N-doped ZIF-derived carbon is ground into powder, mixed with thiourea at a mass ratio of 1:2 and ground again. The mixture is then placed in a tube furnace and calcined at 500°C for 2 hours under nitrogen protection to obtain a black sulfur-doped carbonized product. S4. Add the black sulfur-doped carbonized product to 1-3 mol / L hydrochloric acid, with a solid-liquid ratio of 1 g: 20-50 mL, and stir in a water bath at 40-60℃ for 6-12 h. Transfer the mixture to a probe-type ultrasonic cell disruptor and perform ultrasonic treatment under ice bath conditions. The ultrasonic power is 300-500 W, the working / interrupting time is 5 s / 2 s, and the total treatment time is 50-80 min to obtain sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles.

[0014] Preferably, the molar ratio of zinc nitrate hexahydrate to 2-methylimidazole is 1:8.

[0015] The preparation method of the above-mentioned low-side-etching, high-precision two-component copper etching solution includes the following steps: Hydrogen peroxide, PEG-b-PAA, sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles, imidazolinyl betaine, and organic carboxylic acids were used. Sulfuric acid or phosphoric acid is added sequentially to deionized water to obtain reagent A; Poly(N-isopropylacrylamide-co-vinylimidazole), Cu-EDTA chelate, glycine, organic acid, organic base, and auxiliary corrosion inhibitor were added sequentially to deionized water to obtain Agent B. Mix agent A and agent B at a mass ratio of (1.5~3):1 to obtain a copper etching solution.

[0016] Preferably, agent A and agent B are mixed in a mass ratio of 2:1.

[0017] Beneficial effects: The etching solution of this invention has the following advantages: The carbon-doped microparticles of this invention possess a high specific surface area and abundant microporous structure derived from ZIF-8, and the sulfur and nitrogen heteroatoms introduced on their surface provide a large number of polar sites. These sites can preferentially adsorb onto grain boundaries, defects, or high-energy surfaces of the copper layer, forming a dense physical / chemical adsorption film. This film can effectively prevent the etchant from diffusing to the sides of the copper layer, thereby significantly inhibiting lateral etching while allowing vertical etching to proceed normally. PEG-b-PAA (polyethylene glycol-block-polyacrylic acid) itself can form a polymer film with a certain degree of flexibility, but this film may be disturbed during continuous etching. As rigid nanoparticles, the carbon-doped microparticles can be embedded in the polymer film to form a polymer / nanoparticle composite network structure, making the composite film more dense and uniform, further improving the lateral etching inhibition effect. This invention utilizes a composite surfactant system of PEG-b-PAA block copolymer and imidazoline betaine in Agent A, where the two work synergistically to wetting, dispersing, and interface regulation. The polyethylene glycol (PEG) segments in the PEG-b-PAA molecule possess excellent hydrophilicity and steric stabilization effects, forming a hydration protective layer on the surface of carbon nanoparticles. This prevents aggregation and sedimentation in acidic, high-ionic-strength environments, ensuring the long-term dispersion stability of the nanocatalyst. The polyacrylic acid (PAA) segments, containing carboxylate groups, can weakly coordinate with the copper surface, forming an adsorption film. Imidazoline betaine, as an amphoteric surfactant, exhibits a strong affinity for the copper surface with its imidazoline rings. These rings can align at the etching interface, with the hydrophobic alkyl chains facing the bulk solution and the hydrophilic groups facing the copper surface. This improves the wettability of the etching solution on the copper surface, promoting uniform penetration of the etchant in micro-grooves and densely packed areas, effectively eliminating localized under-etching or over-etching caused by poor wetting. When the two are combined, the steric hindrance effect of the long chain of PEG-b-PAA and the interfacial directional adsorption effect of imidazoline betaine work synergistically to form a composite adsorption layer with selective permeability on the copper surface. This adsorption layer has moderate permeability to hydrogen peroxide molecules and hydrogen ions required for longitudinal etching, ensuring the continuous etching reaction. However, it has a certain hindering effect on the transverse diffusion of copper ions and etching products, thus effectively suppressing lateral drilling without significantly reducing the etching rate. This invention introduces poly(N-isopropylacrylamide-co-vinylimidazole) as a temperature-responsive functional polymer into agent B. This polymer organically combines the temperature-sensitive properties of N-isopropylacrylamide with the metal coordination ability of vinylimidazole through random copolymerization, endowing the etching solution with a unique temperature adaptive control function. The lower critical solution temperature of poly(N-isopropylacrylamide) homopolymer is about 32°C. In the initial stage of etching, the etching solution temperature is usually set below 32°C. At this time, the temperature-sensitive polymer is in a hydrophilic swelling state, the molecular chains are fully extended, and the coverage of the copper surface is low. The etchant can freely approach the copper surface, achieving rapid and efficient initial etching. As etching progresses, the etching solution temperature can be gradually increased to above 32°C through a temperature control system. The temperature-sensitive polymer undergoes a hydrophobic phase transition, the molecular chains shrink and aggregate, forming a denser physical barrier layer on the copper surface. At the same time, the coordination effect between the vinylimidazole groups and the copper surface is enhanced, further inhibiting the lateral diffusion of the etchant. Thus, in the later stage of etching, precise suppression of lateral etching and fine trimming of the etching contour are achieved. This invention utilizes a Cu-EDTA chelate and glycine as a composite copper ion stabilizing system in agent B, effectively solving the technical challenges of accelerated hydrogen peroxide decomposition and etching rate degradation under high copper loading. In the Cu-EDTA chelate, copper ions are firmly coordinated by the four carboxylic acid groups and two amino groups of EDTA, significantly reducing the catalytic activity of free copper ions for hydrogen peroxide decomposition. When agents A and B are mixed, the Cu-EDTA chelate acts as a buffer reservoir for copper ions, dynamically releasing or complexing copper ions according to changes in the concentration of free copper ions in the etching solution, maintaining the relative stability of copper ion activity in the system. Glycine, as an auxiliary complexing agent, can form complexes with copper ions through its amino and carboxyl groups, forming a gradient complexation system with EDTA. This invention employs an organic acid and organic base combination to construct a pH buffer system in Agent B, effectively stabilizing the acidity environment of the mixed etching solution. The organic acid in Agent B provides the acidic component, while the organic base provides the alkaline component. After mixing, they form a weak acid-weak base buffer pair, which can stabilize the pH value of the etching solution within a reasonable range. This ensures the oxidative etching activity of hydrogen peroxide on copper while avoiding the attack of excessive acidity on the underlying insulating layer and photoresist. The introduction of the auxiliary corrosion inhibitor benzotriazole and its derivatives forms an extremely thin chemical adsorption film on the copper surface. This, together with the physical barrier of the temperature-sensitive polymer and the interface regulation of the block copolymer, forms a triple protection mechanism, further suppressing excessive corrosion and pitting during the etching process, ensuring the integrity and electrical reliability of the etched copper circuitry. Detailed Implementation

[0018] The present invention will be further described below with reference to embodiments. These embodiments are illustrative of the present invention, but the present invention is not limited to these embodiments: PEG-b-PAA, Hangzhou Xinqiao Biotechnology Co., Ltd., PDI < 1.4, PEG segment: 6000 Da; PAA segment: 5000 Da; Poly(N-isopropylacrylamide-co-vinylimidazole) was prepared in-house, and the specific preparation method is as follows: N-isopropylacrylamide and vinylimidazolium monomer were added to anhydrous methanol at a molar ratio of 85:15 and stirred until completely dissolved to obtain a mixed solution with a total concentration of 15 wt%. AIBN was added to anhydrous ethanol and stirred until completely dissolved to obtain an initiator solution with a concentration of 0.1 g / mL; Under continuous nitrogen protection and stirring, the initiator solution was rapidly injected into the mixed solution. The molar ratio of AIBN to vinylimidazolium monomer was 1:15. The reaction system was immediately heated to 60°C and maintained at a constant temperature for 10 h. Then, it was slowly added dropwise to 3 times the volume of cold n-hexane under vigorous stirring. The copolymer precipitated out, and after washing and drying, poly(N-isopropylacrylamide-co-vinylimidazolium) was obtained.

[0019] Example 1

[0020] The preparation method of sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles includes the following steps: S1. Zinc nitrate hexahydrate and 2-methylimidazole were dispersed in methanol at a molar ratio of 1:8. The zinc nitrate solution was then added to the 2-methylimidazole solution, allowed to stand for aging for 12 hours, filtered and dried to obtain ZIF-8 powder. S2. Place ZIF-8 in a tube furnace, introduce high-purity nitrogen gas for high-temperature calcination, raise the temperature to 800℃ at 2℃ / min, and hold for 2h to obtain N-doped carbonized ZIF-derived carbon. S3. After cooling, the N-doped ZIF-derived carbon is ground into powder, mixed with thiourea at a mass ratio of 1:2 and ground again. The mixture is then placed in a tube furnace and calcined at 500°C for 2 hours under nitrogen protection to obtain a black sulfur-doped carbonized product. S4. The black sulfur-doped carbonized product was added to 1 mol / L hydrochloric acid at a solid-liquid ratio of 1 g: 20 mL. The mixture was stirred in a water bath at 40 °C for 6 h. The mixture was then transferred to a probe-type ultrasonic cell disruptor and subjected to ultrasonic treatment in an ice bath at a power of 300 W with a working / intermittent time of 5 s / 2 s and a total treatment time of 80 min to obtain sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles.

[0021] Example 2

[0022] The preparation method of sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles includes the following steps: S1. Zinc nitrate hexahydrate and 2-methylimidazole were dispersed in methanol at a molar ratio of 1:8. The zinc nitrate solution was then added to the 2-methylimidazole solution, allowed to stand for 24 hours, filtered and dried to obtain ZIF-8 powder. S2. Place ZIF-8 in a tube furnace, introduce high-purity nitrogen gas for high-temperature calcination, raise the temperature to 1000℃ at 5℃ / min, and hold for 4h to obtain N-doped carbonized ZIF-derived carbon. S3. After cooling, the N-doped ZIF-derived carbon is ground into powder, mixed with thiourea at a mass ratio of 1:2 and ground again. The mixture is then placed in a tube furnace and calcined at 500°C for 2 hours under nitrogen protection to obtain a black sulfur-doped carbonized product. S4. The black sulfur-doped carbonized product was added to 3 mol / L hydrochloric acid at a solid-liquid ratio of 1 g: 50 mL. The mixture was stirred in a water bath at 60 °C for 12 h. The mixture was then transferred to a probe-type ultrasonic cell disruptor and subjected to ultrasonic treatment in an ice bath at a power of 500 W, with a working / intermittent time of 5 s / 2 s and a total treatment time of 50 min, to obtain sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles.

[0023] Example 3

[0024] The preparation method of sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles includes the following steps: S1. Zinc nitrate hexahydrate and 2-methylimidazole were dispersed in methanol at a molar ratio of 1:8. The zinc nitrate solution was then added to the 2-methylimidazole solution, allowed to stand for aging for 20 hours, filtered and dried to obtain ZIF-8 powder. S2. Place ZIF-8 in a tube furnace, introduce high-purity nitrogen gas for high-temperature calcination, raise the temperature to 900℃ at 3℃ / min, and hold for 3h to obtain N-doped carbonized ZIF-derived carbon. S3. After cooling, the N-doped ZIF-derived carbon is ground into powder, mixed with thiourea at a mass ratio of 1:2 and ground again. The mixture is then placed in a tube furnace and calcined at 500°C for 2 hours under nitrogen protection to obtain a black sulfur-doped carbonized product. S4. The black sulfur-doped carbonized product was added to 2 mol / L hydrochloric acid at a solid-liquid ratio of 1 g: 40 mL. The mixture was stirred in a water bath at 50 °C for 10 h. The mixture was then transferred to a probe-type ultrasonic cell disruptor and subjected to ultrasonic treatment in an ice bath at a power of 400 W with a working / intermittent time of 5 s / 2 s and a total treatment time of 60 min to obtain sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles.

[0025] Table 1 shows the particle size of the nanocarbon particles in Examples 1-3.

[0026] Example 4

[0027] The preparation method of Cu-EDTA chelate includes the following steps: Weigh out disodium ethylenediaminetetraacetate and dissolve it in deionized water. Adjust the pH to 4.5, heat to 60°C, and stir to obtain a 0.3 mol / L colorless and transparent solution A. Weigh out copper sulfate pentahydrate and dissolve it in deionized water to obtain a 1 mol / L blue solution B; Solution B was slowly added dropwise to solution A with stirring, the volume ratio of solution A to solution B was 3:1, the pH was maintained at 4.5, and stirring was continued for 30 min after the addition was completed. Then, the solution was concentrated to about 1 / 3 of its volume by rotary evaporation at 60 °C. After cooling to 4 °C and standing for 24 h, dark blue columnar crystals precipitated. The crystals were filtered, washed with cold water and dried under vacuum to obtain Cu-EDTA chelate.

[0028] Example 5

[0029] The preparation method of Cu-EDTA chelate includes the following steps: Weigh out disodium ethylenediaminetetraacetate and dissolve it in deionized water. Adjust the pH to 5.0, heat to 60°C, and stir to obtain a 0.3 mol / L colorless and transparent solution A. Weigh out copper sulfate pentahydrate and dissolve it in deionized water to obtain a 1 mol / L blue solution B; Solution B was slowly added dropwise to solution A with stirring, the volume ratio of solution A to solution B was 3:1, the pH was maintained at 5.0, and stirring was continued for 60 min after the addition was completed. Then, the solution was concentrated to about 1 / 3 of its volume by rotary evaporation at 70 °C. After cooling to 4 °C and standing for 12 h, dark blue columnar crystals precipitated. The crystals were filtered, washed with cold water and dried under vacuum to obtain Cu-EDTA chelate.

[0030] Example 6

[0031] A low-side-etching, high-precision two-component copper etching solution comprises component A and component B, wherein component A comprises the following components in parts by weight: 8 parts hydrogen peroxide 0.5 parts of PEG-b-PAA Example 3: 0.3 parts of sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles. 0.1 part of lauryl imidazoline betaine 1 part citric acid 2 parts phosphoric acid 67 parts of deionized water; Agent B contains the following components in parts by weight: 1 part of poly(N-isopropylacrylamide-co-vinylimidazolium) 0.3 parts of Cu-EDTA chelate prepared in Example 4 0.5 parts glycine 10 parts acetic acid 10 parts of tetramethylammonium hydroxide 0.05 parts of N-butylbenzotriazole 45 parts deionized water; The preparation method of the above-mentioned low-side-etching, high-precision two-component copper etching solution includes the following steps: Hydrogen peroxide, PEG-b-PAA, sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles, lauryl imidazoline betaine, citric acid, and phosphoric acid were sequentially added to deionized water to obtain Agent A. Poly(N-isopropylacrylamide-co-vinylimidazole), Cu-EDTA chelate, glycine, acetic acid, tetramethylammonium hydroxide, and N-butylbenzotriazole were added sequentially to deionized water to obtain agent B. Mix agent A and agent B at a mass ratio of 3:1 to obtain a copper etching solution.

[0032] Example 7

[0033] A low-side-etching, high-precision two-component copper etching solution comprises component A and component B, wherein component A comprises the following components in parts by weight: 15 parts hydrogen peroxide PEG-b-PAA 3 parts 0.8 parts of sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles prepared in Example 3 1 part lauryl imidazoline betaine 5 parts tartaric acid 8 parts sulfuric acid 88 parts of deionized water; Agent B contains the following components in parts by weight: 4 parts of poly(N-isopropylacrylamide-co-vinylimidazolium) One part of the Cu-EDTA chelate prepared in Example 5 1 part glycine 25 parts of acetic acid 20 parts monoethanolamine 0.5 parts of benzotriazole 78 parts of deionized water; The preparation method of the above-mentioned low-side-etching, high-precision two-component copper etching solution includes the following steps: Hydrogen peroxide, PEG-b-PAA, sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles, lauryl imidazoline betaine, tartaric acid, and sulfuric acid were sequentially added to deionized water to obtain Agent A. Poly(N-isopropylacrylamide-co-vinylimidazole), Cu-EDTA chelate, glycine, acetic acid, monoethanolamine, and benzotriazole were added sequentially to deionized water to obtain agent B. Mix agent A and agent B at a mass ratio of 1.5:1 to obtain a copper etching solution.

[0034] Example 8

[0035] A low-side-etching, high-precision two-component copper etching solution comprises component A and component B, wherein component A comprises the following components in parts by weight: 10 parts hydrogen peroxide PEG-b-PAA 1.2 parts 0.4 parts of sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles prepared in Example 1 0.3 parts of lauryl imidazoline betaine 2 parts citric acid 4 parts sulfuric acid 75 parts deionized water; Agent B contains the following components in parts by weight: 2 parts of poly(N-isopropylacrylamide-co-vinylimidazolium) 0.5 parts of Cu-EDTA chelate prepared in Example 4 0.6 parts glycine 15 parts of acetic acid 12 parts of tetramethylammonium hydroxide 0.15 parts of methylbenzotriazole 55 parts deionized water; The preparation method of the above-mentioned low-side-etching, high-precision two-component copper etching solution includes the following steps: Hydrogen peroxide, PEG-b-PAA, sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles, lauryl imidazoline betaine, citric acid, and sulfuric acid were sequentially added to deionized water to obtain Agent A. Poly(N-isopropylacrylamide-co-vinylimidazole), Cu-EDTA chelate, glycine, acetic acid, tetramethylammonium hydroxide, and methylbenzotriazole were added sequentially to deionized water to obtain agent B. Mix agent A and agent B at a mass ratio of 2:1 to obtain a copper etching solution.

[0036] Example 9

[0037] A low-side-etching, high-precision two-component copper etching solution comprises component A and component B, wherein component A comprises the following components in parts by weight: 13 parts hydrogen peroxide PEG-b-PAA 2.2 parts 0.6 parts of sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles prepared in Example 2 0.6 parts of lauryl imidazoline betaine Citric acid 4 parts 6 parts sulfuric acid 80 parts deionized water; Agent B contains the following components in parts by weight: 3 parts of poly(N-isopropylacrylamide-co-vinylimidazolium) 0.8 parts of Cu-EDTA chelate prepared in Example 5 0.9 parts glycine 20 parts of acetic acid 18 parts of tetramethylammonium hydroxide 0.35 parts of methylbenzotriazole 60 parts deionized water; The preparation method of the above-mentioned low-side-etching, high-precision two-component copper etching solution includes the following steps: Hydrogen peroxide, PEG-b-PAA, sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles, lauryl imidazoline betaine, citric acid, and sulfuric acid were sequentially added to deionized water to obtain Agent A. Poly(N-isopropylacrylamide-co-vinylimidazole), Cu-EDTA chelate, glycine, acetic acid, tetramethylammonium hydroxide, and methylbenzotriazole were added sequentially to deionized water to obtain agent B. Mix agent A and agent B at a mass ratio of 2:1 to obtain a copper etching solution.

[0038] Comparative Example 1 The difference between Comparative Example 1 and Example 9 is that sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles are not added.

[0039] Comparative Example 2 The difference between Comparative Example 2 and Example 9 is that PEG-b-PAA is not added.

[0040] Comparative Example 3 The difference between Comparative Example 3 and Example 9 is that poly(N-isopropylacrylamide-co-vinylimidazole) is not added.

[0041] Comparative Example 4 The difference between Comparative Example 4 and Example 9 is that Cu-EDTA chelate is not added.

[0042] Comparative Example 5 The difference between Comparative Example 5 and Example 9 is that PEG-b-PAA is replaced with a PEG segment of 500 Da and a PAA segment of 2500 Da. Comparative Example 6 The difference between Comparative Example 6 and Example 9 is that PEG-b-PAA was replaced with a PEG homopolymer with a molecular weight of 6000 Da.

[0043] Comparative Example 7 The difference between Example 7 and Example 9 is that sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles are replaced with undoped ZIF-8 carbon.

[0044] Comparative Example 8 The difference between Comparative Example 8 and Example 9 is that Agent A and Agent B are mixed in a mass ratio of 4:1.

[0045] Comparative Example 9 The difference between Comparative Example 9 and Example 9 is that the sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles were not subjected to ultrasonic pulverization.

[0046] Comparative Example 10 The difference between Comparative Example 10 and Example 9 is that the molecular weight of poly(N-isopropylacrylamide-co-vinylimidazole) is 3000 Da.

[0047] Performance testing The two-component copper etching solutions prepared in Examples 6-9 and Comparative Examples 1-10 above were subjected to performance testing. Etching rate: Under the same conditions (temperature: 35℃, etching object: copper foil substrate with a thickness of 35μm), the etching time was measured and the etching rate (μm / min) was calculated. Etching uniformity: The difference in etching depth between different areas (center and edge) of the substrate after etching is measured and expressed as uniformity (minimum etching depth / maximum etching depth × 100%). The higher the value, the better the uniformity. Lateral etching amount: Using photoresist as a mask, the lateral distance (μm) of copper etched below the mask edge is measured by metallographic microscope after etching. Copper surface flatness: After etching, the copper surface morphology is observed using a scanning electron microscope. The evaluation criteria are: excellent (smooth surface, no micro-bumps), good (basically flat surface, with a few micro-bumps), poor (obviously rough surface, with many bumps). Storage stability: Agent A and Agent B were stored separately at 40℃ in a sealed container for 30 days, and the presence of precipitation or stratification was observed. Then they were mixed and an etching test was performed. The change rate of the etching rate was measured as ((initial rate - rate after 30 days) / initial rate × 100%). The smaller the change rate, the better the stability. The test results are summarized in Table 2.

[0048] Table 2

[0049] Comparative Examples 1, 7, and 9 show that the absence of carbon nanoparticles or the use of undoped / unultrasonicated particles significantly increased the lateral etching amount (2.4~4.0 μm), indicating that the specific structure of sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles, the chemisorption of sulfur functional groups, and optimized particle size are the material basis for lateral etching suppression. Comparative Examples 2, 5, and 6 show that the absence of PEG-b-PAA or the use of low molecular weight / homopolymers as substitutes both affect dispersion stability, etching uniformity, and lateral etching. The amphiphilic structure of the block copolymer is the core of constructing a selectively permeable composite adsorption layer. Comparative Examples 3 and 10 show that the use of temperature-sensitive polymers or low molecular weight products significantly increased the lateral etching amount in the later stages of etching. Comparative Examples 4 and 8 show that the absence of Cu-EDTA or an imbalance in the ratio of agent A and agent B both led to drastic fluctuations in etching rate and a sharp deterioration in storage stability.

[0050] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A low-side-etching, high-precision two-component copper etching solution, characterized in that, It contains Agent A and Agent B, wherein Agent A contains the following components in parts by weight: 8-15 parts hydrogen peroxide PEG-b-PAA 0.5~3 parts Sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles, 0.3~0.8 parts 0.1 to 1 part imidazolinyl betaine 1-5 parts of organic carboxylic acids 2-8 parts sulfuric acid or phosphoric acid 67-88 parts deionized water; Agent B contains the following components in parts by weight: 1-4 parts of poly(N-isopropylacrylamide-co-vinylimidazolium) 0.3-1 part of Cu-EDTA chelate Glycine 0.5-1 part 10-25 parts organic acids 10-20 parts of organic base 0.05~0.5 parts of auxiliary corrosion inhibitor 45-78 parts of deionized water.

2. The low-side etching, high-precision two-component copper etching solution according to claim 1, characterized in that: The A agent The molecular weight of PEG-b-PAA is 5000~20000 Da; Imidazolinyl betaine is any one of dodecyl imidazolinyl betaine, hydroxyethyl oleic acid imidazolinyl betaine, or lauryl imidazolinyl betaine; The organic acid is either citric acid or tartaric acid.

3. The low-side etching, high-precision two-component copper etching solution according to claim 1, characterized in that: The molecular weight of poly(N-isopropylacrylamide-co-vinylimidazole) in agent B is 8000~15000 Da; The organic acid is either methanesulfonic acid or acetic acid; The organic base is either tetramethylammonium hydroxide or monoethanolamine; The auxiliary corrosion inhibitor is any one or a combination of benzotriazole, methylbenzotriazole, 1-hydroxybenzotriazole, and N-butylbenzotriazole.

4. The low-side etching, high-precision two-component copper etching solution according to claim 1, characterized in that: The preparation method of the Cu-EDTA chelate includes the following steps: Weigh out disodium ethylenediaminetetraacetate and dissolve it in deionized water. Adjust the pH to 4.5–5.0, heat to 60°C, and stir to obtain a 0.3 mol / L colorless and transparent solution A. Weigh out copper sulfate pentahydrate and dissolve it in deionized water to obtain a 1 mol / L blue solution B; Solution B was slowly added dropwise to solution A with stirring, maintaining the pH at 4.5–5.

5. After the addition was complete, stirring was continued for 30–60 min. Then, the solution was concentrated to about 1 / 3 of its volume by rotary evaporation at 60–70 °C. The solution was cooled to 4 °C and allowed to stand for 12–24 h to precipitate dark blue columnar crystals. The crystals were filtered, washed with cold water, and dried under vacuum to obtain Cu-EDTA chelate.

5. The low-side etching, high-precision two-component copper etching solution according to claim 1, characterized in that: The preparation method of the sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles includes the following steps: S1. Disperse zinc nitrate hexahydrate and 2-methylimidazole separately in methanol, then add the zinc nitrate solution to the 2-methylimidazole solution, let stand for aging for 12-24 hours, filter and dry to obtain ZIF-8 powder; S2. Place ZIF-8 in a tube furnace, introduce high-purity nitrogen gas for high-temperature calcination, raise the temperature to 800~1000℃ at 2~5℃ / min, and hold for 2~4h to obtain N-doped carbonized ZIF-derived carbon. S3. After cooling, the N-doped ZIF-derived carbon is ground into powder, mixed with thiourea at a mass ratio of 1:2 and ground again. The mixture is then placed in a tube furnace and calcined at 500°C for 2 hours under nitrogen protection to obtain a black sulfur-doped carbonized product. S4. Add the black sulfur-doped carbonized product to 1-3 mol / L hydrochloric acid, with a solid-liquid ratio of 1 g: 20-50 mL, and stir in a water bath at 40-60℃ for 6-12 h. Transfer the mixture to a probe-type ultrasonic cell disruptor and perform ultrasonic treatment under ice bath conditions. The ultrasonic power is 300-500 W, the working / interrupting time is 5 s / 2 s, and the total treatment time is 50-80 min to obtain sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles.

6. The low-side etching, high-precision two-component copper etching solution according to claim 1, characterized in that: The molar ratio of zinc nitrate hexahydrate to 2-methylimidazole is 1:

8.

7. The method for preparing the low-side etching, high-precision two-component copper etching solution according to claim 1, characterized in that, Includes the following steps: Hydrogen peroxide, PEG-b-PAA, sulfur / nitrogen co-doped ZIF-8 derived carbon nanoparticles, imidazolinyl betaine, and organic carboxylic acids were used. Sulfuric acid or phosphoric acid is added sequentially to deionized water to obtain agent A; Poly(N-isopropylacrylamide-co-vinylimidazole), Cu-EDTA chelate, glycine, organic acid, organic base, and auxiliary corrosion inhibitor were sequentially added to deionized water to obtain Agent B. Mix agent A and agent B at a mass ratio of (1.5~3):1 to obtain a copper etching solution.

8. The method for preparing the low-side etching, high-precision two-component copper etching solution according to claim 1, characterized in that: Agent A and Agent B are mixed at a mass ratio of 2:1.

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