Positive photoresist stripping liquid and preparation method thereof

Abstract

The invention belongs to the technical field of photoresist, and particularly discloses positive photoresist stripping liquid which comprises the following components in percentage by mass: 35-60% of a polar organic solvent, 10-20% of organic alkali, 3-6% of a metal protective agent, 1.5-3% of an imidazoline derivative, 0.5-2% of gamma-piperazinyl propyl methyl dimethoxy silane, 0.5-2.5% of sodium borate, 0.5-1% of a surfactant and the balance of water. According to the positive photoresist stripping liquid provided by the invention, all the components have a synergistic effect, the stripping speed is high, the residual photoresist rate is low, and a copper substrate can be well protected.

Description

Technical Field

[0001] The invention belongs to the technical field of photoresists, and in particular relates to a positive photoresist stripping solution and a preparation method thereof. Background Art

[0002] Positive photoresist (positive photoresist) is a key material in the photolithography process. After being irradiated with light of a specific wavelength, the chemical properties of the light-receiving part will change and become soluble in the developer, so that the pattern on the mask can be accurately transferred to the substrate material. The active ingredients of common positive photoresists are linear phenolic resins and diazonaphthoquinone photosensitive compounds, which can realize the production of fine patterns and are widely used in semiconductor manufacturing, flat panel displays, micro-electromechanical systems and other fields.

[0003] Positive photoresist stripping solution is a chemical solution used to remove unexposed or unnecessary positive photoresist after the photolithography process. When the positive photoresist stripping solution comes into contact with the copper substrate, due to the presence of impurities, lattice defects or different crystal orientations on the surface of the copper substrate, microscopic electrochemical inhomogeneity will be formed, resulting in potential differences between different areas on the surface of the copper substrate, thus forming many tiny galvanic cells, which will accelerate the corrosion of the copper substrate. Moreover, the corrosion products will form a loose film on the surface of the copper substrate, which will not only fail to protect the copper substrate, but will also hinder the contact between the stripping solution and the positive photoresist, reducing the stripping efficiency of the positive photoresist. At the same time, the corrosion products will remain on the surface of the copper substrate, affecting the subsequent processes, and then affecting the adhesion of the metal wiring, leading to poor welding and other problems.

[0004] The Chinese invention patent document with publication number CN117872693A discloses a positive photoresist stripping solution, a preparation method of the positive photoresist stripping solution and its application. The positive photoresist stripping solution includes the following components in the following concentration ratios: 22-28 g / L of an amine compound; 27-33 g / L of a first positive photoresist resin solvent; 22-30 g / L of a second positive photoresist resin solvent; 0.01-8 g / L of an additive; the balance is water; the amine compound includes any one of N,N-diethyl-1,3-propylenediamine, N,N-diisopropyl-1,3-propylenediamine, diethylenetriamine and N-(2-hydroxyethyl)ethylenediamine; the first positive photoresist resin solvent is a dibasic acid ester DBE or propylene carbonate; the second positive photoresist resin solvent is 3-methoxy-3 methyl-1-butanol or 2-methyl-2,4-pentanediol. The positive photoresist stripping solution has a fast stripping speed and a low residual adhesive rate, but still cannot protect the copper substrate well. Summary of the invention

[0005] The purpose of the present invention is to overcome the above problems existing in the prior art and provide a positive photoresist stripping solution, the components of which work synergistically, have a fast stripping speed, a low residual photoresist rate, and can better protect the copper 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] In a first aspect, the present invention provides a positive photoresist stripping solution, which comprises the following components, calculated by mass percentage: 35-60% polar organic solvent, 10-20% organic base, 3-6% metal protective agent, 1.5-3% imidazoline derivative, 0.5-2% γ-piperazinepropylmethyldimethoxysilane, 0.5-2.5% sodium borate, 0.5-1% surfactant, and the balance is water.

[0008] Furthermore, the polar organic solvent is at least one of N-methylformamide, N-methylpyrrolidone, N,N-dimethylformamide, diethylene glycol monomethyl ether, ethylene glycol methyl ether, and dimethyl sulfoxide.

[0009] Furthermore, the organic base is at least one of diglycolamine, ethylene glycolamine, diethanolamine, triethanolamine, methyldiethanolamine, and hydroxyethylethylenediamine.

[0010] Furthermore, the preparation method of the metal protective agent comprises the following steps:

[0011] Step (1), dissolving cyanuric chloride in acetone, adding 2-mercaptobenzothiazole, adjusting the pH to 8-9 with sodium hydroxide solution, reflux reacting at 60-70° C. for 8-10 hours, adding ice water, stirring, filtering, and drying to obtain an intermediate;

[0012] Step (2), adding the intermediate to N,N-dimethylformamide, adding 1,4-butanediamine aqueous solution to the reaction system, heating to 90-110°C after the addition is completed, stirring for reaction for 4-8 hours, cooling the reaction system to 30-35°C, filtering, washing, drying, recrystallizing, filtering again, and drying again to obtain a metal protective agent.

[0013] Furthermore, the reaction formula of the preparation method of the metal protective agent is as follows:

[0014]

[0015] Furthermore, the ratio of the amount of cyanuric chloride, 2-mercaptobenzothiazole, 1,4-butanediamine aqueous solution, N,N-dimethylformamide, and acetone is (18.1-18.5) g: (30.5-31.5) g: (11-15) g: (100-200) g: (100-200) g.

[0016] Furthermore, the concentration of the 1,4-butanediamine aqueous solution is 25-35 wt %.

[0017] Furthermore, the imidazoline derivative is at least one of lauryl hydroxyethyl imidazoline, heptadecenylaminoethyl imidazoline, undecyl imidazoline, dodecyl hydroxyethyl imidazoline, oleyl hydroxyethyl imidazoline and heptadecenyl hydroxyethyl imidazoline.

[0018] Furthermore, the mass ratio of the metal protective agent to the imidazoline derivative is (1-3):1.

[0019] Furthermore, the surfactant is at least one of nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, polyethylene glycol and octadecylamine polyoxyethylene ether.

[0020] In a second aspect, the present invention provides a method for preparing a positive photoresist stripping solution, comprising the following steps: according to the positive photoresist stripping solution formula, weighing a polar organic solvent, an organic base, a metal protective agent, an imidazoline derivative, γ-piperazinepropylmethyldimethoxysilane, sodium borate, a surfactant, and water, mixing and dissolving all the materials completely, then heating to 40-60°C, stirring until uniform and transparent, to obtain a positive photoresist stripping solution.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. In the positive photoresist stripping solution provided by the present invention, the polar organic solvent and the organic base work together to form a cascade effect of "swelling-degradation-dissolution": (a) the organic solvent destroys the physical cross-linking, causing the positive photoresist structure to relax; (b) the organic base penetrates the cross-linking effect between the weak molecular chains; (c) the small molecular degradation products are further dissolved by the organic solvent, causing the positive photoresist to lose its original structure and performance and smoothly detach from the copper substrate.

[0023] 2. In the positive photoresist stripping solution provided by the present invention, the nitrogen-containing heterocyclic rings and sulfur atoms in the metal protective agent can provide lone pairs of electrons, form coordination bonds with the empty orbitals on the surface of the metal copper, and undergo chemical adsorption, so that the metal protective agent molecules are tightly attached to the surface of the metal copper, and the molecules are arranged in order through van der Waals forces and π-π stacking effects to form a continuous protective film with a certain thickness and strength. The protective film plays a role in isolating the corrosive medium and slowing down metal corrosion; and the conjugated system of the benzene ring and the heterocyclic ring can disperse the electron cloud, reduce the electron density on the surface of the metal copper, inhibit the dissolution of copper ions, and play an effect of protecting the metal.

[0024] 3. In the positive photoresist stripping solution provided by the present invention, the nitrogen-containing heterocyclic ring in the imidazoline derivative molecule will be adsorbed on the surface of metallic copper, and can also interact with the metal protective agent to synergistically enhance the stability and corrosion resistance of the protective film; at the same time, the imidazoline derivative can reduce the surface tension of the stripping solution, so that the stripping solution can better wet the surface of the positive photoresist and the copper substrate, improve the penetration ability of the stripping solution, and promote the stripping solution to penetrate into the interface between the positive photoresist and the substrate, thereby more effectively stripping the positive photoresist from the copper substrate.

[0025] 4. In the positive photoresist stripping solution provided by the present invention, the methoxy group in the γ-piperazinylpropylmethyldimethoxysilane molecule is hydrolyzed in water to generate a silanol group, so that the silane coupling agent forms a silane film on the surface of the copper substrate. The silane film reduces the direct contact area between the positive photoresist and the copper substrate through the steric hindrance effect. At the same time, the piperazine group forms a hydrogen bond with the phenolic hydroxyl group in the positive photoresist, which promotes the swelling and stripping of the positive photoresist. The piperazine group can also interact with other components in the stripping solution to enhance the protective effect of the copper substrate.

[0026] 5. In the positive photoresist stripping solution provided by the present invention, the molecular structures of the metal protective agent and the imidazoline derivative have large steric hindrance, and molecular gaps will be generated when a protective film is formed on the surface of the copper substrate, resulting in some areas not being effectively covered and forming protective blind spots; by adding small molecule sodium borate, it can penetrate and fill in these gaps, making the protective film structure more compact and complete, thereby constructing a denser and more stable composite protective film, and significantly improving the anti-corrosion effect of the stripping solution on the copper substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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:

[0028] Figure 1 is an OM image of a sample after being stripped using the positive photoresist stripping solution of Example 1 provided by the present invention;

[0029] Figure 2 is an OM image of a sample after being stripped using the positive photoresist stripping solution of Comparative Example 2 provided by the present invention;

[0030] Figure 3 is an OM image of a sample after being stripped using the positive photoresist stripping solution of Comparative Example 4 provided by the present invention;

[0031] Figure 4 is a SEM picture of a sample before and after stripping using the positive photoresist stripping solution of Example 1 provided by the present invention; Figure 4 In the figure, A is a SEM image of the sample before being stripped by the positive photoresist stripping solution of Example 1, and B is a SEM image of the sample after being stripped by the positive photoresist stripping solution of Example 1;

[0032] Figure 5 is a SEM picture of a sample before and after stripping using the positive photoresist stripping solution of Comparative Example 3 provided by the present invention; Figure 5 In the figure, A is a SEM image of the sample before being stripped by the positive photoresist stripping solution of Comparative Example 3, and B is a SEM image of the sample after being stripped by the positive photoresist stripping solution of Comparative Example 3;

[0033] Figure 6 is a SEM picture of a sample before and after stripping using the positive photoresist stripping solution of Comparative Example 5 provided by the present invention; Figure 6 In the figure, A is a SEM image of the sample before stripping using the positive photoresist stripping solution of Comparative Example 5, and B is a SEM image of the sample after stripping using the positive photoresist stripping solution of Comparative Example 5. DETAILED DESCRIPTION

[0034] 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.

[0035] Preparation Example 1

[0036] This preparation example provides a metal protective agent, which is prepared by the following method:

[0037] Step (1) dissolving 18.1 g of cyanuric chloride in 100 g of acetone, adding 30.5 g of 2-mercaptobenzothiazole, adjusting the pH to 8 with sodium hydroxide solution, reacting at 60° C. for 10 h under reflux, adding ice water, stirring, filtering, and drying to obtain 33.7 g of an intermediate with a purity greater than 99%;

[0038] Step (2) Add the intermediate obtained in step (1) to 100 g of N,N-dimethylformamide, and dropwise add 15 g (25 wt%) of 1,4-butanediamine aqueous solution into the reaction system. After the dropwise addition is completed, heat to 90° C., stir and react for 8 h, then cool the reaction system to 30° C., filter, wash with acetone and dry at 60° C. for 4 h, recrystallize with ethyl acetate and acetone (volume ratio 1:1), filter, and dry to obtain 28.8 g of a metal protective agent with a purity greater than 99%.

[0039] Preparation Example 2

[0040] This preparation example provides a metal protective agent, which is prepared by the following method:

[0041] Step (1) dissolving 18.3 g of cyanuric chloride in 150 g of acetone, adding 31.0 g of 2-mercaptobenzothiazole, adjusting the pH to 8.5 with sodium hydroxide solution, reacting at 65° C. for 9 h under reflux, adding ice water, stirring, filtering, and drying to obtain 35.5 g of an intermediate with a purity greater than 99%;

[0042] Step (2) The intermediate obtained in step (1) is added to 150 g of N,N-dimethylformamide, and 11 g (35 wt%) of 1,4-butanediamine aqueous solution is added dropwise to the reaction system. After the addition is completed, the temperature is raised to 100° C. and stirred for reaction for 6 hours. The reaction system is then cooled to 32° C., filtered, washed with acetone and dried at 60° C. for 4 hours, recrystallized using ethyl acetate and acetone (volume ratio of 1:1), filtered, and dried to obtain 30.4 g of a metal protective agent with a purity greater than 99%.

[0043] Preparation Example 3

[0044] This preparation example provides a metal protective agent, which is prepared by the following method:

[0045] Step (1) dissolving 18.5 g of cyanuric chloride in 200 g of acetone, adding 31.5 g of 2-mercaptobenzothiazole, adjusting the pH to 9 with sodium hydroxide solution, reacting at 70° C. for 8 h under reflux, adding ice water, stirring, filtering, and drying to obtain 37.6 g of an intermediate with a purity of 99%;

[0046] Step (2) The intermediate obtained in step (1) is added to 200 g of N,N-dimethylformamide, and 14 g (30 wt%) of 1,4-butanediamine aqueous solution is added dropwise to the reaction system. After the addition is completed, the temperature is raised to 110° C. and stirred for reaction for 4 hours. The reaction system is then cooled to 35° C., filtered, washed with acetone and dried at 60° C. for 4 hours, recrystallized using ethyl acetate and acetone (volume ratio of 1:1), filtered, and dried to obtain 33.6 g of a metal protective agent with a purity greater than 99%.

[0047] Example 1

[0048] Embodiment 1 provides a positive photoresist stripping solution and a preparation method thereof, which are specifically as follows:

[0049] A positive photoresist stripping solution, comprising, by mass percentage, 60% of a polar organic solvent, 10% of an organic base, 4.5% of a metal protective agent, 1.5% of an imidazoline derivative, 0.5% of γ-piperazinepropylmethyldimethoxysilane, 0.5% of sodium borate, 0.5% of a surfactant, and the balance being water;

[0050] The polar organic solvent is obtained by mixing N-methylformamide and ethylene glycol methyl ether in a mass ratio of 1:1; the organic base is ethylene glycol amine; the metal protective agent is prepared by Preparation Example 1; the imidazoline derivative is lauryl hydroxyethyl imidazoline; and the surfactant is nonylphenol polyoxyethylene ether;

[0051] A method for preparing a positive photoresist stripping solution comprises the following steps:

[0052] Weigh each component in the above formula according to mass percentage, mix and dissolve all materials completely, then heat to 40° C. and stir until uniform and transparent to obtain a positive photoresist stripping solution.

[0053] Example 2

[0054] Embodiment 2 provides a positive photoresist stripping solution and a preparation method thereof, as follows:

[0055] A positive photoresist stripping solution, comprising, by mass percentage, 45% of a polar organic solvent, 15% of an organic base, 3% of a metal protective agent, 3% of an imidazoline derivative, 1% of γ-piperazinepropylmethyldimethoxysilane, 1.5% of sodium borate, 0.8% of a surfactant, and the balance being water;

[0056] Wherein, the polar organic solvent is N-methylpyrrolidone; the organic base is triethanolamine; the metal protective agent is prepared by Preparation Example 2; the imidazoline derivative is heptadecaenylamineethylimidazoline; the surfactant is polyethylene glycol;

[0057] A method for preparing a positive photoresist stripping solution comprises the following steps:

[0058] Weigh each component in the above formula according to mass percentage, mix and dissolve all materials completely, then heat to 50° C. and stir until uniform and transparent to obtain a positive photoresist stripping solution.

[0059] Example 3

[0060] Embodiment 3 provides a positive photoresist stripping solution and a preparation method thereof, as follows:

[0061] A positive photoresist stripping solution, comprising, by mass percentage, 35% of a polar organic solvent, 20% of an organic base, 6% of a metal protective agent, 3% of an imidazoline derivative, 2% of γ-piperazinepropylmethyldimethoxysilane, 2.5% of sodium borate, 1% of a surfactant, and the balance being water;

[0062] Wherein, the polar organic solvent is obtained by mixing N,N-dimethylformamide and dimethyl sulfoxide in a mass ratio of 2:1; the organic base is diethanolamine; the metal protective agent is prepared by Preparation Example 3; the imidazoline derivative is obtained by mixing oleyl hydroxyethyl imidazoline and heptadecenyl hydroxyethyl imidazoline in a mass ratio of 1:1; the surfactant is octadecylamine polyoxyethylene ether;

[0063] A method for preparing a positive photoresist stripping solution comprises the following steps:

[0064] Weigh each component in the above formula according to mass percentage, mix and dissolve all materials completely, then heat to 60° C. and stir until uniform and transparent to obtain a positive photoresist stripping solution.

[0065] Example 4

[0066] Embodiment 4 provides a positive photoresist stripping solution and a preparation method thereof, which are as follows:

[0067] A positive photoresist stripping solution, comprising, by mass percentage, 45% of a polar organic solvent, 20% of an organic base, 5.5% of a metal protective agent, 3% of an imidazoline derivative, 0.5% of γ-piperazinepropylmethyldimethoxysilane, 2.5% of sodium borate, 1% of a surfactant, and the balance being water;

[0068] Wherein, the polar organic solvent is N-methylpyrrolidone; the organic base is methyldiethanolamine; the metal protective agent is prepared by Preparation Example 2; the imidazoline derivative is dodecylhydroxyethylimidazoline; and the surfactant is polyethylene glycol;

[0069] A method for preparing a positive photoresist stripping solution comprises the following steps:

[0070] Weigh each component in the above formula according to mass percentage, mix and dissolve all materials completely, then heat to 40° C. and stir until uniform and transparent to obtain a positive photoresist stripping solution.

[0071] Example 5

[0072] Embodiment 5 provides a positive photoresist stripping solution and a preparation method thereof, which are as follows:

[0073] A positive photoresist stripping solution, comprising, by mass percentage, 50% of a polar organic solvent, 13% of an organic base, 5% of a metal protective agent, 2% of an imidazoline derivative, 1% of γ-piperazinepropylmethyldimethoxysilane, 1.5% of sodium borate, 0.8% of a surfactant, and the balance being water;

[0074] Wherein, the polar organic solvent is obtained by mixing N-methylformamide and dimethyl sulfoxide in a mass ratio of 1:1; the organic base is hydroxyethylethylenediamine; the metal protective agent is prepared by Preparation Example 3; the imidazoline derivative is undecyl imidazoline; the surfactant is octadecylamine polyoxyethylene ether;

[0075] A method for preparing a positive photoresist stripping solution comprises the following steps:

[0076] Weigh each component in the above formula according to mass percentage, mix and dissolve all materials completely, then heat to 60° C. and stir until uniform and transparent to obtain a positive photoresist stripping solution.

[0077] Comparative Example 1

[0078] Comparative Example 1 provides a positive photoresist stripping solution and a preparation method thereof.

[0079] The difference between Comparative Example 1 and Example 1 is that an equal mass of 2-mercaptobenzothiazole is used to replace the metal protective agent (prepared in Preparation Example 1), specifically as follows:

[0080] A positive photoresist stripping solution, comprising, by mass percentage, 60% of a polar organic solvent, 10% of an organic base, 4.5% of 2-mercaptobenzothiazole, 1.5% of an imidazoline derivative, 0.5% of γ-piperazinepropylmethyldimethoxysilane, 0.5% of sodium borate, 0.5% of a surfactant, and the balance being water;

[0081] The polar organic solvent is obtained by mixing N-methylformamide and ethylene glycol methyl ether in a mass ratio of 1:1; the organic base is ethylene glycol amine; the imidazoline derivative is lauryl hydroxyethyl imidazoline; the surfactant is nonylphenol polyoxyethylene ether;

[0082] A method for preparing a positive photoresist stripping solution comprises the following steps:

[0083] Weigh each component in the above formula according to mass percentage, mix and dissolve all materials completely, then heat to 40° C. and stir until uniform and transparent to obtain a positive photoresist stripping solution.

[0084] Comparative Example 2

[0085] Comparative Example 2 provides a positive photoresist stripping solution and a preparation method thereof.

[0086] The difference between Comparative Example 2 and Example 1 is that an equal mass of a metal protective agent (prepared in Preparation Example 1) is used to replace the imidazoline derivative, as follows:

[0087] A positive photoresist stripping solution, comprising, by mass percentage, 60% of a polar organic solvent, 10% of an organic base, 6% of a metal protective agent, 0.5% of γ-piperazinepropylmethyldimethoxysilane, 0.5% of sodium borate, 0.5% of a surfactant, and the balance being water;

[0088] Wherein, the polar organic solvent is obtained by mixing N-methylformamide and ethylene glycol methyl ether in a mass ratio of 1:1; the organic base is ethylene glycol amine; the metal protective agent is prepared by Preparation Example 1; the surfactant is nonylphenol polyoxyethylene ether;

[0089] A method for preparing a positive photoresist stripping solution comprises the following steps:

[0090] Weigh each component in the above formula according to mass percentage, mix and dissolve all materials completely, then heat to 40° C. and stir until uniform and transparent to obtain a positive photoresist stripping solution.

[0091] Comparative Example 3

[0092] Comparative Example 3 provides a positive photoresist stripping solution and a preparation method thereof.

[0093] The difference between Comparative Example 3 and Example 1 is that an equal mass of imidazoline derivative is used to replace the metal protective agent (prepared in Preparation Example 1), as follows:

[0094] A positive photoresist stripping solution, comprising, by mass percentage, 60% of a polar organic solvent, 10% of an organic base, 6% of an imidazoline derivative, 0.5% of γ-piperazinepropylmethyldimethoxysilane, 0.5% of sodium borate, 0.5% of a surfactant, and the balance being water;

[0095] The polar organic solvent is obtained by mixing N-methylformamide and ethylene glycol methyl ether in a mass ratio of 1:1; the organic base is ethylene glycol amine; the imidazoline derivative is lauryl hydroxyethyl imidazoline; the surfactant is nonylphenol polyoxyethylene ether;

[0096] A method for preparing a positive photoresist stripping solution comprises the following steps:

[0097] Weigh each component in the above formula according to mass percentage, mix and dissolve all materials completely, then heat to 40° C. and stir until uniform and transparent to obtain a positive photoresist stripping solution.

[0098] Comparative Example 4

[0099] Comparative Example 4 provides a positive photoresist stripping solution and a preparation method thereof.

[0100] The difference between Comparative Example 4 and Example 1 is that γ-piperazinylpropylmethyldimethoxysilane is not added, specifically as follows:

[0101] A positive photoresist stripping solution, comprising, by mass percentage, 60% of a polar organic solvent, 10% of an organic base, 4.5% of a metal protective agent, 1.5% of an imidazoline derivative, 0.5% of sodium borate, 0.5% of a surfactant, and the balance being water;

[0102] The polar organic solvent is obtained by mixing N-methylformamide and ethylene glycol methyl ether in a mass ratio of 1:1; the organic base is ethylene glycol amine; the metal protective agent is prepared by Preparation Example 1; the imidazoline derivative is lauryl hydroxyethyl imidazoline; and the surfactant is nonylphenol polyoxyethylene ether;

[0103] A method for preparing a positive photoresist stripping solution comprises the following steps:

[0104] Weigh each component in the above formula according to mass percentage, mix and dissolve all materials completely, then heat to 40° C. and stir until uniform and transparent to obtain a positive photoresist stripping solution.

[0105] Comparative Example 5

[0106] Comparative Example 5 provides a positive photoresist stripping solution and a preparation method thereof.

[0107] The difference between Comparative Example 5 and Example 1 is that sodium borate is not added, specifically as follows:

[0108] A positive photoresist stripping solution, comprising, by mass percentage, 60% of a polar organic solvent, 10% of an organic base, 4.5% of a metal protective agent, 1.5% of an imidazoline derivative, 0.5% of γ-piperazinepropylmethyldimethoxysilane, 0.5% of a surfactant, and the balance being water;

[0109] The polar organic solvent is obtained by mixing N-methylformamide and ethylene glycol methyl ether in a mass ratio of 1:1; the organic base is ethylene glycol amine; the metal protective agent is prepared by Preparation Example 1; the imidazoline derivative is lauryl hydroxyethyl imidazoline; and the surfactant is nonylphenol polyoxyethylene ether;

[0110] A method for preparing a positive photoresist stripping solution comprises the following steps:

[0111] Weigh each component in the above formula according to mass percentage, mix and dissolve all materials completely, then heat to 40° C. and stir until uniform and transparent to obtain a positive photoresist stripping solution.

[0112] Performance Testing

[0113] The positive photoresist stripping solution prepared in the embodiment and the comparative example was used to treat the copper substrate containing the positive photoresist, and the stripping effect of the substrate after stripping was evaluated. The relevant experimental process and evaluation parameters are as follows:

[0114] Stripping method: At 60° C., the substrate sample containing the positive photoresist was immersed in the positive photoresist stripping solution prepared in the embodiments of the present invention and the comparative example for stripping for 120 seconds, then rinsed with ultrapure water for 1 minute, and finally dried with high-purity nitrogen to prepare a sample after positive photoresist stripping solution stripping.

[0115] Stripping effect: After cleaning, use an optical microscope (OM) to observe the surface of the copper substrate sample to check whether there is any photoresist residue; use a scanning electron microscope (SEM) to measure the change in the thickness of the copper film layer; and measure the amount of Cu dissolved in the stripping solution to evaluate the corrosion of the metal layer;

[0116] The relevant experimental results are shown in Table 1;

[0117] Table 1

[0118]

[0119]

[0120] It can be seen from the above table that the performance of the stripping solutions of Examples 1-5 is significantly better than that of Comparative Examples 1-5.

[0121] Collect OM and SEM images of the sample during the positive photoresist stripping process. The results are as follows: Figure 1-6 As shown, Figure 1 OM image of the sample after being stripped using the positive photoresist stripping solution of Example 1; Figure 2 OM image of the sample after stripping using the positive photoresist stripping solution of Comparative Example 2; Figure 3 OM image of the sample after stripping using the positive photoresist stripping solution of Comparative Example 4; Figure 4 A is a SEM image of the sample before being stripped by the positive photoresist stripping solution of Example 1, and B is a SEM image of the sample after being stripped by the positive photoresist stripping solution of Example 1; Figure 5 A is a SEM image of the sample before being stripped by the positive photoresist stripping solution of Comparative Example 3, and B is a SEM image of the sample after being stripped by the positive photoresist stripping solution of Comparative Example 3; Figure 6 A is a SEM image of the sample before stripping using the positive photoresist stripping solution of Comparative Example 5, and B is a SEM image of the sample after stripping using the positive photoresist stripping solution of Comparative Example 5.

[0122] comprehensive Figure 1-6 According to the data in Table 1, comparing Example 1 with Comparative Example 1, it is shown that the stripping solution of the present invention has excellent corrosion resistance compared with 2-mercaptobenzothiazole by adding the metal protective agent prepared in Preparation Example 1; comparing Example 1 with Comparative Examples 2 and 3, it is shown that the metal protective agent and the imidazoline derivative in the stripping solution of the present invention are used together, which is not only beneficial to protect the copper substrate, but also can improve the stripping effect of the stripping solution; comparing Example 1 with Comparative Example 4, it is shown that the addition of γ-piperazinylpropylmethyldimethoxysilane to the stripping solution of the present invention can effectively enhance the stripping effect and corrosion resistance; comparing Example 1 with Comparative Example 5, it is shown that the addition of sodium borate to the stripping solution of the present invention can work together with other components to improve the corrosion resistance of the stripping solution.

[0123] 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.

[0124] 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 positive photoresist stripping solution, characterized in that: The invention comprises the following components by mass percentage: 35-60% of polar organic solvent, 10-20% of organic base, 3-6% of metal protective agent, 1.5-3% of imidazoline derivative, 0.5-2% of gamma-piperazinepropylmethyldimethoxysilane, 0.5-2.5% of sodium borate, 0.5-1% of surfactant, and the balance is water.

2. A positive photoresist stripping solution according to claim 1, characterized in that: The polar organic solvent is at least one of N-methylformamide, N-methylpyrrolidone, N,N-dimethylformamide, diethylene glycol monomethyl ether, ethylene glycol methyl ether and dimethyl sulfoxide.

3. A positive photoresist stripping solution according to claim 1, characterized in that: The organic base is at least one of diglycolamine, ethylene glycolamine, diethanolamine, triethanolamine, methyldiethanolamine and hydroxyethylethylenediamine.

4. The positive photoresist stripping solution according to claim 1, characterized in that: The preparation method of the metal protective agent comprises the following steps: Step (1), dissolving cyanuric chloride in acetone, adding 2-mercaptobenzothiazole, adjusting the pH to 8-9 with sodium hydroxide solution, reflux reacting at 60-70° C. for 8-10 hours, adding ice water, stirring, filtering, and drying to obtain an intermediate; Step (2), adding the intermediate to N,N-dimethylformamide, adding 1,4-butanediamine aqueous solution to the reaction system, heating to 90-110°C after the addition is completed, stirring for reaction for 4-8 hours, cooling the reaction system to 30-35°C, filtering, washing, drying, recrystallizing, filtering again, and drying again to obtain a metal protective agent.

5. A positive photoresist stripping solution according to claim 4, characterized in that: The usage ratio of cyanuric chloride, 2-mercaptobenzothiazole, 1,4-butanediamine aqueous solution, N,N-dimethylformamide and acetone is (18.1-18.5) g: (30.5-31.5) g: (11-15) g: (100-200) g: (100-200) g.

6. The positive photoresist stripping solution according to claim 4, characterized in that: The concentration of the 1,4-butanediamine aqueous solution is 25-35 wt %.

7. The positive photoresist stripping solution according to claim 1, characterized in that: The imidazoline derivative is at least one of lauryl hydroxyethyl imidazoline, heptadecenylaminoethyl imidazoline, undecyl imidazoline, dodecyl hydroxyethyl imidazoline, oleyl hydroxyethyl imidazoline and heptadecenyl hydroxyethyl imidazoline.

8. The positive photoresist stripping solution according to claim 1, characterized in that: The mass ratio of the metal protective agent to the imidazoline derivative is (1-3):

1.

9. The positive photoresist stripping solution according to claim 1, characterized in that: The surfactant is at least one of nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, polyethylene glycol and octadecylamine polyoxyethylene ether.

10. A method for preparing a positive photoresist stripping solution according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: according to the positive photoresist stripping solution formula, polar organic solvent, organic base, metal protective agent, imidazoline derivative, γ-piperazinepropylmethyldimethoxysilane, sodium borate, surfactant and water are weighed, all materials are mixed and dissolved completely, then the temperature is raised to 40-60° C., and stirred until uniform and transparent to obtain the positive photoresist stripping solution.

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