Low-damage composite acidic cleaning agent for precision mask plate and application thereof

Abstract

This invention discloses a low-damage, composite acidic cleaning agent for precision photomasks and its application, relating to the field of organic light-emitting diode (OLED) manufacturing technology. This low-damage, composite acidic cleaning agent for precision photomasks comprises the following raw materials in parts by weight: 60-70 parts deionized water, 3-5 parts hydroxyethylidene diphosphonic acid, 2-4 parts citric acid monohydrate, 0.5-1 parts benzotriazole, 3-5 parts ethylene glycol monobutyl ether, 4-6 parts modified fatty alcohol polyoxyethylene ether, 5-7 parts modified polyvinylpyrrolidone K-30, and 1-2 parts polyethylene glycol 400. This cleaning agent uses a fluorine-free, mild acidic formula, providing low-damage protection to the photomask substrate; its components exhibit strong synergistic effects, efficiently removing various contaminants such as photoresist residue and metal ions; the system has excellent compatibility, with no precipitation or secondary pollution; it is environmentally friendly and safe, with a simple preparation process, adaptable to various cleaning methods, and has broad industrial application prospects.

Description

Technical Field

[0001] This invention relates to the field of organic light-emitting diode manufacturing technology, specifically to a low-damage composite acidic cleaning agent for precision photomasks and its application. Background Technology

[0002] As a core photolithography component in semiconductors, flat panel displays, and other fields, the efficient and low-damage removal of photoresist residues, metal ion impurities, and inorganic oxide stains from the surface of precision photomasks directly affects process accuracy and product yield.

[0003] In existing technologies, photomask cleaning agents are mainly classified into three categories: alkaline systems, strong acid systems, and fluorine-containing systems. Alkaline cleaning agents remove organic residues through saponification, but they have weak dissolving ability for inorganic oxides and easily cause swelling of the metal pattern layer. Strong acid cleaning agents can quickly dissolve inorganic stains and metal ions, but they are highly corrosive and easily cause quartz substrate erosion and metal layer grain boundary damage. Fluorine-containing cleaning agents have excellent cleaning efficiency, but residual fluoride ions can cause long-term corrosion and do not meet environmental protection requirements. At the same time, conventional cleaning agents often have problems with redundant component functions or poor synergy. Surfactants have insufficient compatibility with acidic systems, which can easily lead to precipitation and secondary pollution. Dispersants have limited anti-adsorption capacity, making it difficult to meet the stringent requirements of precision photomasks for low damage and high cleanliness.

[0004] Therefore, developing a fluorine-free, mildly acidic cleaning agent with strong component synergy, which can simultaneously achieve efficient decontamination and substrate protection, has become a technical challenge that the industry urgently needs to solve. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a low-damage, composite acidic cleaning agent for precision photomasks and its application, solving the problems of strong corrosiveness, incomplete decontamination, poor system compatibility, easy secondary pollution, and insufficient environmental friendliness of existing cleaning agents.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A low-damage, composite acidic cleaning agent for precision photomasks comprises the following raw materials in parts by weight: 60-70 parts deionized water, 3-5 parts hydroxyethylidene diphosphonic acid, 2-4 parts citric acid monohydrate, 0.5-1 part benzotriazole, 3-5 parts ethylene glycol monobutyl ether, 4-6 parts modified fatty alcohol polyoxyethylene ether, 5-7 parts modified polyvinylpyrrolidone (PVP) K-30, and 1-2 parts polyethylene glycol 400.

[0008] Furthermore, the modified fatty alcohol polyoxyethylene ether is prepared using the following specific steps:

[0009] A1. Take fatty alcohol polyoxyethylene ether, mix it with anhydrous ethanol and stir evenly. Cool the system to 0-5℃ in an ice-water bath. Pre-disperse phosphorus pentoxide with anhydrous ethanol, and then slowly add it dropwise to the above solution, controlling the temperature <10℃. Low temperature control suppresses side reactions and ensures that monoesterification is the main process. After the addition is complete, slowly raise the temperature to 50-55℃ and react for 3-4 hours. Add deionized water and maintain the temperature for hydrolysis for 2 hours. Hydrolysis converts the phosphate ester into a more stable monoester / diester mixture, enhancing water solubility and acid compatibility. After the hydrolysis is completed, distill under reduced pressure at -0.095MPa and 60℃ until it becomes viscous. There is no obvious distillate. Add anhydrous ethanol to dissolve it, filter it while hot to remove unreacted P2O5 and by-product salts, and prevent low-temperature solidification from clogging the filter material. Distill the filtrate again under reduced pressure to remove ethanol, and obtain intermediate product 1. The introduction of phosphate ester groups enhances hydrophilicity and metal chelating ability.

[0010] A2. Add intermediate product 1 and anhydrous toluene to a three-necked flask. Toluene, as a non-polar solvent, forms an azeotropic system with water, which is beneficial for dehydration in the esterification reaction. Turn on nitrogen protection and heat to 85°C, stirring for 30 minutes to dehydrate. Nitrogen protection prevents high-temperature oxidation, and dehydration ensures the forward esterification reaction. Cool to 70-80°C, add tetrabutyl titanate and 2,6-di-tert-butyl-p-cresol, and stir for 10 minutes until homogeneous. Tetrabutyl titanate acts as a transesterification catalyst, and 2,6-di-tert-butyl-p-cresol acts as an antioxidant to suppress side reactions. Then add maleic anhydride, stirring until completely dissolved, and slowly heat to 100-110°C to allow the maleic anhydride to gradually open the ring. Esterification was performed to avoid local cross-linking. The water separator was turned on and the reaction was kept at a constant temperature for 4-5 hours until no water was discharged from the water separator. The generated water was removed from the water separator in real time to push the esterification equilibrium toward the product. The temperature was then lowered to 70°C, and p-hydroxyanisole was added as a polymerization inhibitor to prevent the product from polymerizing and deteriorating at high temperature. The mixture was stirred for 15 minutes. After the reaction was completed, the product was distilled under reduced pressure at -0.095 MPa and 73°C for 3 hours to remove toluene and trace residues. The heated product was then adsorbed and filtered through a short column packed with neutral alumina. Finally, it was filtered through a 0.1 μm PTFE membrane filter to obtain intermediate product 2. Maleic anhydride groups were introduced to enhance the compatibility and reactivity with the organic residual membrane.

[0011] A3. Add intermediate product 2 and deionized water to a high-pressure reactor, purge with nitrogen three times, and stir to 85-90℃. Add triethanolamine as a catalyst to activate the hydroxyl groups and initiate the ring-opening of ethylene oxide. Stir for 10 min. Slowly introduce ethylene oxide at a rate of 0.5-1.0 g / min, maintaining a temperature of 85-95℃ and a pressure of 0.1-0.3 MPa. Medium temperature and pressure ensure that ethylene oxide is in the liquid phase, improving reaction efficiency and safety. Maintain the temperature for 30-60 min to ensure complete conversion of unreacted ethylene oxide and uniform molecular weight of the product. After the reaction, cool to room temperature and slowly adjust the pH to 6.5-7.0 with glacial acetic acid. Terminate the reaction with a weak acid to neutralize the catalyst and prevent subsequent storage degradation. Remove water and trace amounts of residual ethylene oxide by vacuum distillation at -0.09 MPa and 60℃. Then cool to 40℃ and filter through a 0.1 μm PTFE membrane filter to obtain modified fatty alcohol polyoxyethylene ether. By introducing polyethylene oxide segments and precisely controlling the HLB value, the compatibility of water-based acidic systems can be enhanced.

[0012] Furthermore, the ratio of fatty alcohol polyoxyethylene ether, anhydrous ethanol, phosphorus pentoxide, and deionized water in A1 is 100g: 50-70ml: 15-20g: 6-10ml; wherein the ratio of anhydrous ethanol used in mixing with fatty alcohol polyoxyethylene ether and phosphorus pentoxide is 30-40ml: 20-30ml; the fatty alcohol polyoxyethylene ether is AEO-9 type with a degree of polymerization of 8-10.

[0013] Furthermore, the ratio of intermediate product 1, anhydrous toluene, tetrabutyl titanate, 2,6-di-tert-butyl-p-cresol, maleic anhydride, and p-hydroxyanisole in A2 is 100g: 40-50ml: 0.8-1.2g: 0.08-0.1g: 12-18g: 0.08-0.1g.

[0014] Furthermore, the ratio of intermediate product 2, deionized water, triethanolamine, and ethylene oxide in A3 is 100g: 15-20ml: 1.0-1.5g: 8-12g.

[0015] Furthermore, the modified polyvinylpyrrolidone K-30 is prepared using the following specific steps:

[0016] B1. Take polyvinylpyrrolidone K-30 and mix it with anhydrous ethanol, and sonicate until completely dissolved. Add benzoyl peroxide and n-dodecyl mercaptan. Benzoyl peroxide acts as an oil-soluble initiator, which decomposes thermally to generate free radicals. n-Dodecyl mercaptan acts as a chain transfer agent to control the length of the grafted chain and prevent cross-linking. Under nitrogen protection, heat to 76-80℃ to prevent free radical oxidation and deactivation. Medium temperature ensures the controllable decomposition of benzoyl peroxide. Mix methyl methacrylate with anhydrous ethanol and add it dropwise at constant pressure for 3 hours. After the addition is complete, continue the reaction for 2 hours. Distill the reaction solution under reduced pressure at -0.085 MPa and 50℃ until there is no obvious distillate to obtain intermediate product A. Grafting methyl methacrylate introduces ester side chains, increases steric hindrance, and initially improves the dispersibility.

[0017] B2. Take intermediate product A and mix it with anhydrous methanol to dissolve it. Add anhydrous potassium carbonate as an acid-binding agent to neutralize the carboxylic acid generated by ammonolysis and promote the reaction to proceed in the forward direction. Under nitrogen protection, heat to 40-44℃. Low temperature prevents ethanolamine from volatilizing and controls the ammonolysis rate to avoid excessive cross-linking. Slowly add ethanolamine dropwise, completing the addition in 30 minutes to ensure that monosubstitution is the main process and to prevent intermolecular cross-linking caused by difunctional amines. Keep the reaction at this temperature for 6 hours. After the reaction is completed, cool to room temperature, filter to remove salt, and distill the filtrate under reduced pressure at -0.09 MPa and 55℃ until no obvious distillate is obtained to obtain intermediate product B. The introduction of ethanolamine groups enhances water solubility and acid compatibility and provides active reaction sites.

[0018] B3. Take intermediate product B and mix it with a water-ethanol mixed solvent, stirring until completely dissolved. Add anhydrous sodium carbonate as an acid-binding agent to neutralize the HCl generated during sulfonation and maintain the weak alkalinity of the system. Raise the temperature to 66-70℃. Add sodium 3-chloro-2-hydroxypropanesulfonate in three batches, with an interval of 30 min between each batch, to control the reaction rate and prevent local overheating that could lead to the decomposition of sulfonic acid groups. Continue the reaction for 4 hours after the addition is complete. After the reaction is complete, cool to room temperature and transfer to a dialysis bag with a molecular weight cutoff of 3500 Da. Dialyze with deionized water for 24 hours. Transfer the dialysate to a rotary evaporator and concentrate it under reduced pressure at 50℃ and -0.095 MPa until it reaches a viscous state to avoid thermal degradation. Transfer it to a vacuum drying oven and dry it under vacuum at 60℃ and -0.09 MPa for 12 hours. Grind it into powder to obtain modified polyvinylpyrrolidone K-30. The introduction of sulfonic acid groups enhances the adsorption to the quartz substrate and the ability to disperse and prevent secondary adsorption.

[0019] Furthermore, the ratio of polyvinylpyrrolidone K-30, anhydrous ethanol, benzoyl peroxide, n-dodecyl mercaptan, and methyl methacrylate in B1 is 100g: 200-225ml: 0.5-0.7g: 0.25-0.35g: 9-11ml; wherein the ratio of anhydrous ethanol used in mixing with polyvinylpyrrolidone K-30 and methyl methacrylate is 180-200ml: 20-25ml.

[0020] Furthermore, the ratio of intermediate product A, anhydrous methanol, anhydrous potassium carbonate, and ethanolamine in B2 is 100g: 55-65ml: 2.2-2.8g: 13-15ml.

[0021] Furthermore, the ratio of intermediate product B, water-ethanol mixed solvent, anhydrous sodium carbonate, and sodium 3-chloro-2-hydroxypropanesulfonate in B3 is 100g:120-140ml:3.0-4.0g:11-13g; wherein the volume ratio of water to ethanol in the water-ethanol mixed solvent is 4:1.

[0022] A method for preparing a low-damage, composite acidic cleaning agent for precision photomasks specifically includes the following steps:

[0023] S1. Add 60-70 parts of deionized water to the stirred tank, stir at 200-300 r / min, heat to 30-35℃, add 3-5 parts of hydroxyethylidene diphosphonic acid and 2-4 parts of citric acid monohydrate in sequence, stir to dissolve for 20 min until the system is completely clear, and obtain acidic chelated base solution.

[0024] S2. In an acidic chelating base solution, maintain a stirring speed of 200-300 r / min and a temperature of 30-35℃, add 0.5-1 part benzotriazole and 3-5 parts ethylene glycol monobutyl ether, and continue stirring for 10 min until the benzotriazole is completely dissolved and the system is homogeneous and free of particles.

[0025] S3. While maintaining the above temperature and stirring speed, slowly add 4-6 parts of modified fatty alcohol polyoxyethylene ether and 5-7 parts of modified polyvinylpyrrolidone K-30 to the system. After adding, increase the stirring speed to 400-500 r / min and stir for 20 min until the system is completely clear, with no suspended particles and no stratification.

[0026] S4. Reduce the stirring speed to 200-300 r / min, add 1-2 parts of polyethylene glycol 400 to the system, continue stirring for 15 min, let stand to defoam, cool to room temperature, and filter through a 500 mesh filter cloth to obtain a homogeneous, clear, low-damage composite acidic precision mask cleaning agent.

[0027] Furthermore, in S3, the modified fatty alcohol polyoxyethylene ether and the modified polyvinylpyrrolidone K-30 are added alternately and slowly to avoid the two polymers coming into contact at high concentrations at the same time, which could lead to copolymerization or flocculation. During the addition process, the system temperature is kept stable at 30-35℃, and the constant temperature ensures the stability of the polymer dissolution and dispersion kinetics.

[0028] Furthermore, the cleaning agent is suitable for removing photoresist residue, metal ion impurities, or inorganic oxide stains from the surface of precision photomasks such as photomasks and metal photomasks.

[0029] This invention provides a low-damage cleaning agent for precision photomasks with complex acidity and its application, which has the following beneficial effects:

[0030] 1. The cleaning agent of this invention achieves one-stop, highly efficient removal of photoresist residue, metal ion impurities, and inorganic oxide stains from the surface of precision photomasks through the synergistic effect of a composite acidic system and functional components. Hydroxyethylidene diphosphonic acid specifically complexes metal ions, citric acid monohydrate gently dissolves inorganic oxides, and ethylene glycol monobutyl ether precisely dissolves organic residual resin components. Combined with a tertiary modified fatty alcohol polyoxyethylene ether, the introduced phosphate ester-carboxyl-polyether chain multifunctional groups significantly enhance the wettability and penetration of photoresist residue. The components are functionally complementary without redundancy, avoiding the shortcomings of single-type cleaning agents that result in incomplete cleaning. It can quickly break down stubborn stains of different properties, meeting the core requirement of high cleanliness for precision photomasks.

[0031] 2. The cleaning agent uses a mild acidic formula, avoiding the risk of corrosion to the photomask by a strong acid system. Simultaneously, it achieves low-damage cleaning through multiple protective designs. Benzotriazole forms a dense passivation film on the surface of the metal pattern layer, effectively inhibiting the corrosion of Invar alloy (Fe-36Ni) and chromium / molybdenum metal layers by the acidic environment. The modified components exhibit excellent compatibility with the quartz substrate, with no swelling phenomenon. Strict control of raw material reaction conditions and post-treatment purity during preparation ensures no substrate scratches or performance degradation caused by impurities. After cleaning, key indicators such as photomask transmittance and linewidth accuracy show no significant changes, guaranteeing its stability in subsequent use. This cleaning agent is widely applicable to FMM cleaning after evaporating cathodes of different alloys: it has the best removal effect on residues from mainstream Mg:Ag and Yb:Ag cathodes; it is also effective for residues from Al-Li and Ca:Al alloy cathodes, requiring only minor adjustments to the cleaning temperature or time based on the residue level.

[0032] 3. This invention solves the problems of poor compatibility and easy precipitation of surfactants in conventional cleaning agents by optimizing and modifying components. The modified fatty alcohol polyoxyethylene ether has an HLB value that is precisely matched to the water-based acidic system, eliminating the risk of stratification or precipitation; polyvinylpyrrolidone K-30, through graft modification, enhances the steric hindrance effect, effectively dispersing the detached stain particles and preventing secondary adsorption; polyethylene glycol 400 further improves the homogeneous stability of each component, ensuring that the cleaning agent does not precipitate or stratify during long-term storage, and that there are no problems with excessive foaming or residue during the cleaning process, achieving the cleanliness standard without complex post-treatment.

[0033] 4. The cleaning agent does not use any prohibited or restricted substances such as fluorine or heavy metals throughout the entire process. Wastewater can be discharged in compliance with standards after conventional neutralization and flocculation treatment, posing no risk of environmental pollution. All raw materials are commonly used low-toxicity components in industry, and there are no violent reactions or harmful gas generation during operation, ensuring high safety. The preparation process uses conventional stirred tanks, high-pressure reactors, and other equipment. The reaction conditions are mild, the steps are clear and repeatable, and no special harsh conditions are required. When applied, it is compatible with various methods such as ultrasonic cleaning, spray cleaning, and immersion cleaning, and is compatible with fully automatic mask cleaning equipment. The cleaning temperature and pressure parameters are mild, which reduces equipment wear and tear and can meet the cleaning needs of different types of precision masks in the semiconductor, flat panel display, and other fields, showing broad prospects for industrial application. Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1: Preparation of a low-damage composite acid cleaning agent for precision photomasks. The specific preparation steps are as follows:

[0036] S1. Add 60 parts of deionized water to the stirred tank, stir at 200 r / min, heat to 30℃, add 3 parts of hydroxyethylidene diphosphonic acid and 2 parts of citric acid monohydrate in sequence, stir to dissolve for 20 min until the system is completely clear, and obtain acidic chelated base solution.

[0037] S2. In an acidic chelating base solution, while maintaining a stirring speed of 200 r / min and a temperature of 30℃, add 0.5 parts of benzotriazole and 3 parts of ethylene glycol monobutyl ether, and continue stirring for 10 min until the benzotriazole is completely dissolved and the system is homogeneous and free of particles.

[0038] S3. While maintaining the above temperature and stirring speed, slowly add 4 parts of modified fatty alcohol polyoxyethylene ether and 5 parts of modified polyvinylpyrrolidone K-30 to the system alternately. Keep the system temperature stable at 30°C during the addition process. After the addition is complete, increase the stirring speed to 400 r / min and stir for 20 min until the system is completely clear, with no suspended particles and no stratification.

[0039] S4. Reduce the stirring speed to 200 r / min, add 1 part of polyethylene glycol 400 to the system, continue stirring for 15 min, let stand to defoam, cool to room temperature, and filter through a 500 mesh filter cloth to obtain a homogeneous, clear, low-damage composite acidic precision mask cleaning agent.

[0040] Example 2: Preparation of a low-damage composite acid cleaning agent for precision photomasks. The specific preparation steps are as follows:

[0041] S1. Add 70 parts of deionized water to the stirred tank, stir at 300 r / min, heat to 35℃, add 5 parts of hydroxyethylidene diphosphonic acid and 4 parts of citric acid monohydrate in sequence, stir to dissolve for 20 min until the system is completely clear, and obtain acidic chelated base solution.

[0042] S2. In an acidic chelating base solution, while maintaining a stirring speed of 300 r / min and a temperature of 35℃, add 1 part benzotriazole and 5 parts ethylene glycol monobutyl ether, and continue stirring for 10 min until the benzotriazole is completely dissolved and the system is homogeneous and free of particles.

[0043] S3. While maintaining the above temperature and stirring speed, slowly add 6 parts of modified fatty alcohol polyoxyethylene ether and 7 parts of modified polyvinylpyrrolidone K-30 to the system alternately. During the addition process, keep the system temperature stable at 35°C. After the addition is complete, increase the stirring speed to 500 r / min and stir for 20 min until the system is completely clear, with no suspended particles and no stratification.

[0044] S4. Reduce the stirring speed to 300 r / min, add 2 parts of polyethylene glycol 400 to the system, continue stirring for 15 min, let stand to defoam, cool to room temperature, and filter through a 500 mesh filter cloth to obtain a homogeneous, clear, low-damage composite acidic precision mask cleaning agent.

[0045] Example 3: Preparation of a low-damage composite acid cleaning agent for precision photomasks. The specific preparation steps are as follows:

[0046] S1. Add 65 parts of deionized water to the stirred tank, stir at 250 r / min, heat to 32℃, add 4 parts of hydroxyethylidene diphosphonic acid and 3 parts of citric acid monohydrate in sequence, stir to dissolve for 20 min until the system is completely clear, and obtain acidic chelated base solution.

[0047] S2. In an acidic chelating base solution, while maintaining a stirring speed of 250 r / min and a temperature of 32℃, add 0.7 parts of benzotriazole and 4 parts of ethylene glycol monobutyl ether, and continue stirring for 10 min until the benzotriazole is completely dissolved and the system is homogeneous and free of particles.

[0048] S3. While maintaining the above temperature and stirring speed, slowly add 5 parts of modified fatty alcohol polyoxyethylene ether and 6 parts of modified polyvinylpyrrolidone K-30 to the system alternately. During the addition process, keep the system temperature stable at 32℃. After the addition is complete, increase the stirring speed to 450r / min and stir for 20min until the system is completely clear, with no suspended particles and no stratification.

[0049] S4. Reduce the stirring speed to 250 r / min, add 1.5 parts of polyethylene glycol 400 to the system, continue stirring for 15 min, let stand to defoam, cool to room temperature, and filter through a 500 mesh filter cloth to obtain a homogeneous, clear, low-damage composite acidic precision mask cleaning agent.

[0050] Example 4: Preparation of modified fatty alcohol polyoxyethylene ether. The specific preparation steps are as follows:

[0051] A1. Take 100g of fatty alcohol polyoxyethylene ether, mix it with 30ml of anhydrous ethanol and stir well. Cool the system to 0℃ in an ice-water bath. Pre-disperse 15g of phosphorus pentoxide with 20ml of anhydrous ethanol, and then slowly add it dropwise to the above solution, controlling the temperature <10℃. After the addition is complete, slowly raise the temperature to 50℃ and react for 3h. Add 6ml of deionized water and maintain the temperature for hydrolysis for 2h. After the hydrolysis is completed, distill under reduced pressure at -0.095MPa and 60℃ until it becomes viscous. There is no obvious distillate. Add anhydrous ethanol to dissolve it, filter it while hot, and distill the filtrate again under reduced pressure to remove ethanol, to obtain intermediate product 1.

[0052] A2. Add 100g of intermediate product 1 and 40ml of anhydrous toluene to a three-necked flask, turn on nitrogen protection, heat to 85℃, and stir to dehydrate for 30min; cool to 70℃, add 0.8g of tetrabutyl titanate and 0.08g of 2,6-di-tert-butyl-p-cresol, and stir for 10min until homogeneous; then add 12g of maleic anhydride, stir until completely dissolved, and slowly heat to 100℃, turn on the water separator, and react at a constant temperature for 4h until no water is discharged from the water separator; then cool to 70℃, add 0.08g of p-hydroxyanisole, and stir for 15min; after the reaction is complete, remove toluene and trace residues by vacuum distillation at -0.095MPa and 73℃ for 3h; pass the warm product through a short column packed with neutral alumina for adsorption filtration; finally filter through a 0.1μm PTFE membrane filter to obtain intermediate product 2;

[0053] A3. Add 100g of intermediate product 2 and 15ml of deionized water to a high-pressure reactor, purge with nitrogen three times, and stir and heat to 85℃. Add 1.0g of triethanolamine and stir for 10min. Slowly introduce 8g of ethylene oxide at a rate of 0.5g / min, maintaining the temperature at 85℃ and the pressure at 0.1MPa, and allow it to mature for 30min. After the reaction is complete, cool to room temperature and slowly adjust the pH to 6.5 with glacial acetic acid. Remove water and trace amounts of residual ethylene oxide by vacuum distillation at -0.09MPa and 60℃. Then cool to 40℃ and filter through a 0.1μm PTFE membrane filter to obtain modified fatty alcohol polyoxyethylene ether.

[0054] Example 5: Preparation of modified fatty alcohol polyoxyethylene ether. The specific preparation steps are as follows:

[0055] A1. Take 100g of fatty alcohol polyoxyethylene ether, mix it with 40ml of anhydrous ethanol and stir well. Cool the system to 5℃ in an ice-water bath. Pre-disperse 20g of phosphorus pentoxide with 30ml of anhydrous ethanol, and then slowly add it dropwise to the above solution, controlling the temperature <10℃. After the addition is complete, slowly raise the temperature to 55℃ and react for 4h. Add 10ml of deionized water and maintain the temperature for hydrolysis for 2h. After the hydrolysis is completed, distill under reduced pressure at -0.095MPa and 60℃ until it becomes viscous. There is no obvious distillate. Add anhydrous ethanol to dissolve it, filter it while hot, and distill the filtrate again under reduced pressure to remove ethanol, to obtain intermediate product 1.

[0056] A2. Add 100g of intermediate product 1 and 50ml of anhydrous toluene to a three-necked flask, turn on nitrogen protection, heat to 85℃, and stir to dehydrate for 30min; cool to 80℃, add 1.2g of tetrabutyl titanate and 0.1g of 2,6-di-tert-butyl-p-cresol, and stir for 10min until homogeneous; then add 18g of maleic anhydride, stir until completely dissolved, and slowly heat to 110℃, turn on the water separator, and react at a constant temperature for 5h until no water is discharged from the water separator; then cool to 70℃, add 0.1g of p-hydroxyanisole, and stir for 15min; after the reaction is complete, remove toluene and trace residues by vacuum distillation at -0.095MPa and 73℃ for 3h; pass the warm product through a short column packed with neutral alumina for adsorption filtration; finally filter through a 0.1μm PTFE membrane filter to obtain intermediate product 2;

[0057] A3. Add 100g of intermediate product 2 and 20ml of deionized water to a high-pressure reactor, purge with nitrogen three times, and stir and heat to 90℃. Add 1.5g of triethanolamine and stir for 10min. Slowly introduce 12g of ethylene oxide at a rate of 1.0g / min, maintain the temperature at 95℃ and the pressure at 0.3MPa, and allow to mature for 60min. After the reaction is complete, cool to room temperature and slowly adjust the pH to 7.0 with glacial acetic acid. Remove water and trace amounts of residual ethylene oxide by vacuum distillation at -0.09MPa and 60℃. Then cool to 40℃ and filter through a 0.1μm PTFE membrane filter to obtain modified fatty alcohol polyoxyethylene ether.

[0058] Example 6: Preparation of modified polyvinylpyrrolidone K-30. The specific preparation steps are as follows:

[0059] B1. Take 100g of polyvinylpyrrolidone K-30 and mix it with 180ml of anhydrous ethanol. Sonicate until completely dissolved. Add 0.5g of benzoyl peroxide and 0.25g of n-dodecyl mercaptan. Heat to 76℃ under nitrogen protection. Mix 9ml of methyl methacrylate with 20ml of anhydrous ethanol and add it dropwise at constant pressure for 3h. After the addition is complete, continue the reaction for 2h. Distill the reaction solution under reduced pressure at -0.085MPa and 50℃ until no obvious distillate is obtained to get intermediate product A.

[0060] B2. Take 100g of intermediate product A and mix it with 55ml of anhydrous methanol and stir to dissolve. Add 2.2g of anhydrous potassium carbonate and heat to 40℃ under nitrogen protection. Slowly add 13ml of ethanolamine dropwise over 30min and keep the reaction at this temperature for 6h. After the reaction is complete, cool to room temperature, filter to remove salt, and distill the filtrate under reduced pressure at -0.09MPa and 55℃ until no obvious distillate is obtained to get intermediate product B.

[0061] B3. Take 100g of intermediate product B and mix it with 120ml of water-ethanol mixed solvent, stirring until completely dissolved; add 3.0g of anhydrous sodium carbonate and heat to 66℃; add 11g of sodium 3-chloro-2-hydroxypropanesulfonate in three batches, with an interval of 30min between each batch, and continue the reaction for 4h after the addition is complete; after the reaction is completed, cool to room temperature, transfer to a dialysis bag with a molecular weight cutoff of 3500Da, dialyze with deionized water for 24h, transfer the dialysate to a rotary evaporator, concentrate it under reduced pressure at 50℃ and -0.095MPa to a viscous state, transfer it to a vacuum drying oven, dry it under vacuum at 60℃ and -0.09MPa for 12h, and then grind it into powder to obtain modified polyvinylpyrrolidone K-30.

[0062] Example 7: Preparation of modified polyvinylpyrrolidone K-30. The specific preparation steps are as follows:

[0063] B1. Take 100g of polyvinylpyrrolidone K-30 and mix it with 200ml of anhydrous ethanol. Sonicate until completely dissolved. Add 0.7g of benzoyl peroxide and 0.35g of n-dodecyl mercaptan. Heat to 80℃ under nitrogen protection. Mix 11ml of methyl methacrylate with 25ml of anhydrous ethanol and add it dropwise at constant pressure for 3h. After the addition is complete, continue the reaction for 2h. Distill the reaction solution under reduced pressure at -0.085MPa and 50℃ until no obvious distillate is obtained to obtain intermediate product A.

[0064] B2. Take 100g of intermediate product A and mix it with 65ml of anhydrous methanol and stir to dissolve. Add 2.8g of anhydrous potassium carbonate and heat to 44℃ under nitrogen protection. Slowly add 15ml of ethanolamine dropwise over 30min and keep the reaction at this temperature for 6h. After the reaction is complete, cool to room temperature, filter to remove salt, and distill the filtrate under reduced pressure at -0.09MPa and 55℃ until no obvious distillate is obtained to get intermediate product B.

[0065] B3. Take 100g of intermediate product B and mix it with 140ml of water-ethanol mixed solvent, stirring until completely dissolved; add 4.0g of anhydrous sodium carbonate and heat to 70℃; add 13g of sodium 3-chloro-2-hydroxypropanesulfonate in three batches, with an interval of 30min between each batch, and continue the reaction for 4h after the addition is complete; after the reaction is completed, cool to room temperature, transfer to a dialysis bag with a molecular weight cutoff of 3500Da, dialyze with deionized water for 24h, transfer the dialysate to a rotary evaporator, concentrate it under reduced pressure at 50℃ and -0.095MPa to a viscous state, transfer it to a vacuum drying oven, dry it under vacuum at 60℃ and -0.09MPa for 12h, and then grind it into powder to obtain modified polyvinylpyrrolidone K-30.

[0066] Comparative Example 1: A low-damage composite acid cleaning agent for precision photomasks was prepared. The specific preparation steps are as follows:

[0067] The remaining steps remain unchanged, except that the modified fatty alcohol polyoxyethylene ether prepared in Example 4 and used in Example 3 are replaced with unmodified fatty alcohol polyoxyethylene ether to prepare a low-damage composite acidic precision mask cleaning agent.

[0068] Comparative Example 2: A low-damage composite acid cleaning agent for precision photomasks was prepared. The specific preparation steps are as follows:

[0069] The remaining steps remain unchanged, except that the modified polyvinylpyrrolidone K-30 prepared in Example 7 and used in Example 3 are replaced with unmodified polyvinylpyrrolidone K-30 to prepare a low-damage composite acidic precision mask cleaning agent.

[0070] Comparative Example 3: A low-damage composite acid cleaning agent for precision photomasks was prepared. The specific preparation steps are as follows:

[0071] The remaining steps remain unchanged, except that the modified fatty alcohol polyoxyethylene ether prepared in Example 4 used in Example 3 is replaced with unmodified fatty alcohol polyoxyethylene ether, and the modified polyvinylpyrrolidone K-30 prepared in Example 7 is replaced with unmodified polyvinylpyrrolidone K-30, so as to prepare a low-damage composite acidic precision mask cleaning agent.

[0072] Performance testing

[0073] Test Project Test methods Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Photoresist residue removal rate (%) Positive photoresist was coated onto a standard chrome plate, and after exposure and development to simulate residual film, the plate was ultrasonically cleaned with a cleaning agent at 50°C for 10 minutes. The residual area ratio was then measured using an optical microscope. 98.5 98.8 99.6 89.2 92.4 82.6 <![CDATA[Residual metal ions (10 10 atoms / cm 2 ).]]> ICP-MS analysis of the total Fe, Cr, Ni, Mg, and Ag ions on the surface of the mask after cleaning. 452 398 285 1256 987 2158 Contact angle (°) The water droplet method is used to test the hydrophilicity of the mask surface after cleaning and to assess the surface cleanliness. 12 10 8 28 22 35

[0074] Performance test results show that the cleaning agents in Examples 1-3, using modified fatty alcohol polyoxyethylene ether and modified polyvinylpyrrolidone K-30, have significantly better overall performance than those in Comparative Examples 1-3, which use unmodified corresponding components or neither of them: the photoresist residue removal rate of the examples is above 98.5%, with Example 3 reaching the highest at 99.6%, while the comparative examples have a maximum of only 92.4% and a minimum of 82.6%; the metal ion residue of the examples is below 452 × 10⁻⁶. 10atoms / cm 2 Example 3 as low as 285×10 10 atoms / cm 2 The proportions are generally higher than 987×10 10 atoms / cm 2 The highest is 2158×10 10 atoms / cm 2 Regarding the contact angle, all examples had a contact angle of less than 12°, with Example 3 having a contact angle of only 8°, indicating superior surface hydrophilicity and cleanliness. The comparative examples, on the other hand, all had a contact angle greater than 22°, with a maximum of 35°, indicating poorer hydrophilicity and cleanliness. This fully demonstrates the key role of the modified components in improving the cleaning agent's detergency, residue prevention, and surface cleanliness.

[0075] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A low-damage composite acidic cleaning agent for a precision mask, characterized by: It contains the following raw materials by weight: 60-70 parts deionized water, 3-5 parts hydroxyethylidene diphosphonic acid, 2-4 parts citric acid monohydrate, 0.5-1 part benzotriazole, 3-5 parts ethylene glycol monobutyl ether, 4-6 parts modified fatty alcohol polyoxyethylene ether, 5-7 parts modified polyvinylpyrrolidone K-30, and 1-2 parts polyethylene glycol 400.

2. The low-damage composite acidic cleaning agent for precision photomasks according to claim 1, characterized in that: The modified fatty alcohol polyoxyethylene ether is prepared using the following specific steps: A1. Take fatty alcohol polyoxyethylene ether, mix it with anhydrous ethanol and stir evenly. Cool the system to 0-5℃ in an ice-water bath. Pre-disperse phosphorus pentoxide with anhydrous ethanol and then slowly add it dropwise to the above solution, controlling the temperature <10℃. After the addition is complete, slowly raise the temperature to 50-55℃ and react for 3-4 hours. Add deionized water and maintain the temperature for hydrolysis for 2 hours. After the reaction is complete, distill under reduced pressure at -0.095MPa and 60℃ until it becomes viscous. There is no obvious distillate. Add anhydrous ethanol to dissolve it and filter it while hot. Distill the filtrate again under reduced pressure to remove ethanol and obtain intermediate product (1). A2. Add intermediate product (1) and anhydrous toluene to a three-necked flask, turn on nitrogen protection, heat to 85°C, and stir to dehydrate for 30 min; cool to 70-80°C, add tetrabutyl titanate and 2,6-di-tert-butyl-p-cresol, and stir for 10 min until homogeneous; then add maleic anhydride, stir until completely dissolved, and slowly heat to 100-110°C, turn on the water separator, and react at a constant temperature for 4-5 h until no water is discharged from the water separator; then cool to 70°C, add p-hydroxyanisole, and stir for 15 min; after the reaction is complete, remove toluene and trace residues by vacuum distillation at -0.095 MPa and 73°C for 3 h; pass the warm product through a short column packed with neutral alumina for adsorption filtration; finally filter through a 0.1 μm PTFE membrane filter to obtain intermediate product (2). A3. Add intermediate product (2) and deionized water to a high-pressure reactor, purge with nitrogen three times, stir and heat to 85-90℃; add triethanolamine and stir for 10 min; slowly introduce ethylene oxide at a rate of 0.5-1.0 g / min, control the temperature at 85-95℃ and the pressure at 0.1-0.3 MPa, and maintain the temperature for 30-60 min; after the reaction is complete, cool to room temperature and slowly adjust the pH to 6.5-7.0 with glacial acetic acid; remove water and trace amounts of residual ethylene oxide by vacuum distillation at -0.09 MPa and 60℃; then cool to 40℃ and filter through a 0.1 μm PTFE membrane filter to obtain modified fatty alcohol polyoxyethylene ether.

3. The low-damage composite acidic cleaning agent for precision photomasks according to claim 2, characterized in that: The ratio of fatty alcohol polyoxyethylene ether, anhydrous ethanol, phosphorus pentoxide, and deionized water in A1 is 100g: 50-70ml: 15-20g: 6-10ml; the ratio of anhydrous ethanol used in mixing with fatty alcohol polyoxyethylene ether and phosphorus pentoxide is 30-40ml: 20-30ml; the fatty alcohol polyoxyethylene ether is AEO-9 type with a degree of polymerization of 8-10. The ratio of intermediate product (1), anhydrous toluene, tetrabutyl titanate, 2,6-di-tert-butyl-p-cresol, maleic anhydride, and p-hydroxyanisole in A2 is 100g: 40-50ml: 0.8-1.2g: 0.08-0.1g: 12-18g: 0.08-0.1g; The ratio of intermediate product (2), deionized water, triethanolamine and ethylene oxide in A3 is 100g: 15-20ml: 1.0-1.5g: 8-12g.

4. The low-damage composite acidic cleaning agent for precision photomasks according to claim 1, characterized in that: The modified polyvinylpyrrolidone K-30 is prepared by the following steps: B1. Take polyvinylpyrrolidone K-30, mix it with anhydrous ethanol, and sonicate until completely dissolved; add benzoyl peroxide and n-dodecyl mercaptan, and heat to 76-80℃ under nitrogen protection; mix methyl methacrylate with anhydrous ethanol, add it dropwise at constant pressure for 3 hours, and continue the reaction for 2 hours after the addition is complete; distill the reaction solution under reduced pressure at -0.085MPa and 50℃ until no obvious distillate is obtained to obtain intermediate product A; B2. Take intermediate product A and mix it with anhydrous methanol and stir to dissolve it; add anhydrous potassium carbonate and heat to 40-44℃ under nitrogen protection; slowly add ethanolamine dropwise over 30 minutes and keep the reaction at this temperature for 6 hours; after the reaction is complete, cool to room temperature, filter to remove salt, and distill the filtrate under reduced pressure at -0.09 MPa and 55℃ until no obvious distillate is obtained to get intermediate product B. B3. Take intermediate product B and mix it with a water-ethanol mixed solvent, stirring until completely dissolved; add anhydrous sodium carbonate and heat to 66-70℃; add sodium 3-chloro-2-hydroxypropanesulfonate in three batches, with an interval of 30 min between each batch, and continue the reaction for 4 h after the addition is complete; after the reaction is completed, cool to room temperature, transfer to a dialysis bag with a molecular weight cutoff of 3500 Da, dialyze with deionized water for 24 h, transfer the dialysate to a rotary evaporator, concentrate it under reduced pressure at 50℃ and -0.095 MPa to a viscous state, transfer it to a vacuum drying oven, dry it under vacuum at 60℃ and -0.09 MPa for 12 h, and then grind it into powder to obtain modified polyvinylpyrrolidone K-30.

5. The low-damage composite acidic cleaning agent for precision photomasks according to claim 4, characterized in that: The ratio of polyvinylpyrrolidone K-30, anhydrous ethanol, benzoyl peroxide, n-dodecyl mercaptan, and methyl methacrylate in B1 is 100g: 200-225ml: 0.5-0.7g: 0.25-0.35g: 9-11ml; wherein the ratio of anhydrous ethanol used in mixing with polyvinylpyrrolidone K-30 and methyl methacrylate is 180-200ml: 20-25ml. The ratio of intermediate product A, anhydrous methanol, anhydrous potassium carbonate, and ethanolamine in B2 is 100g: 55-65ml: 2.2-2.8g: 13-15ml; The ratio of intermediate product B, water-ethanol mixed solvent, anhydrous sodium carbonate, and sodium 3-chloro-2-hydroxypropanesulfonate in B3 is 100g:120-140ml:3.0-4.0g:11-13g; wherein the volume ratio of water to ethanol in the water-ethanol mixed solvent is 4:

1.

6. A method for preparing a low-damage composite acidic cleaning agent for precision photomasks, characterized in that: Specifically, it includes the following steps: S1. Add 60-70 parts of deionized water to the stirred tank, stir at 200-300 r / min, heat to 30-35℃, add 3-5 parts of hydroxyethylidene diphosphonic acid and 2-4 parts of citric acid monohydrate in sequence, stir to dissolve for 20 min until the system is completely clear, and obtain acidic chelated base solution. S2. In an acidic chelating base solution, maintain a stirring speed of 200-300 r / min and a temperature of 30-35℃, add 0.5-1 part benzotriazole and 3-5 parts ethylene glycol monobutyl ether, and continue stirring for 10 min until the benzotriazole is completely dissolved and the system is homogeneous and free of particles. S3. While maintaining the above temperature and stirring speed, slowly add 4-6 parts of modified fatty alcohol polyoxyethylene ether and 5-7 parts of modified polyvinylpyrrolidone K-30 to the system. After adding, increase the stirring speed to 400-500 r / min and stir for 20 min until the system is completely clear, with no suspended particles and no stratification. S4. Reduce the stirring speed to 200-300 r / min, add 1-2 parts of polyethylene glycol 400 to the system, continue stirring for 15 min, let stand to defoam, cool to room temperature, and filter through a 500 mesh filter cloth to obtain a homogeneous, clear, low-damage composite acidic precision mask cleaning agent.

7. The method for preparing a low-damage composite acidic cleaning agent for precision photomasks according to claim 6, characterized in that: In step S3, the modified fatty alcohol polyoxyethylene ether and the modified polyvinylpyrrolidone K-30 are added alternately and slowly dropwise, and the system temperature is kept stable at 30-35℃ during the dropwise addition process to avoid excessive local concentration that could lead to agglomeration.

8. The application of a low-damage, composite acidic cleaning agent for precision photomasks, characterized in that: The cleaning agent is suitable for removing photoresist residue, metal ion impurities, or inorganic oxide stains from the surface of precision photomasks such as photomasks and metal photomasks.