Photoresist stripping solution, preparation method and application thereof

Abstract

The invention discloses a photoresist stripping solution, a preparation method and application thereof, and relates to the technical field of stripping agents. The photoresist stripping solution comprises 20-60 parts of a bicyclic amidine compound, 1-10 parts of a buffer reagent and 40-80 parts of an organic solvent, by weight. Compared with photoresist stripping solutions of systems such as TMAH, by improving the organic base composition of the photoresist stripping solution, using bicyclic amidine compounds such as DBN and DBU as organic bases, it has both the performance of a strong base and the effect of an anti-corrosion agent, effectively improving the problem of a large amount of residual glue after stripping and severe corrosion of the metal layer caused by the high water content of the photoresist stripping solution, and has good application and market prospects in the semiconductor field and the panel display field.

Description

Technical Field

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

[0002] In the process of forming microcircuits in integrated circuits, panel displays, and semiconductor packaging manufacturing, photoresists must be used, including positive photoresists, negative photoresists, dry films, etc. The usual photolithography process requires that after the required circuit pattern is formed through exposure and development, the remaining photoresist must be completely removed and cleaned, and there must not be any photoresist residue, such as: there must not be any residual adsorption of micron-sized photoresist particles. In addition, since there are usually metal layers or dielectric layers such as copper, aluminum, silver, tin, tin-silver, etc. on the substrate, the stripping liquid cannot corrode the metal layer and the dielectric layer, otherwise it will cause the performance of the final manufactured semiconductor device to be reduced or even completely fail.

[0003] With the rapid development of the semiconductor industry and the panel display industry (including liquid crystal display (LCD) and organic laser display (OLED), the critical dimension (CD) of chip circuits is getting smaller and smaller, the requirements for the stripping effect of photoresist stripping liquid are getting higher and higher, and the control of metal corrosion during the stripping process is becoming more and more stringent. Studies have shown that the water content of photoresist stripping liquid plays a vital role in the stripping effect, service life and corrosion of the metal layer of the photoresist stripping liquid.

[0004] Most of the matrix resins of photoresists are polyacrylates and their derivatives, phenolic resins and their derivatives, cycloolefin-maleic anhydride copolymers and polyimides and their derivatives, etc. Most of these polymer resins are hydrophobic. When the water content in the photoresist stripping solution is high, some of the photoresist components stripped off will produce phase separation in the system, forming colloidal particles in the system. These colloidal particles are easily adsorbed on the substrate surface, thereby causing a decrease in the yield of the stripping process. In addition, because the photoresist stripping solution is a strong alkaline solution, when the water content is high, the degree of ionization of organic bases such as tetramethylammonium hydroxide will increase, and it is easy to attack the metal layer. Although there is an anti-corrosion effect of the resist, compared with the condition of low water content, high water content is more likely to cause corrosion of the metal layer and produce defective products.

[0005] Usually, the water content of photoresist stripping solution is 2.0-5.0%. In order to obtain a photoresist stripping solution with a lower water content, Chinese patent CN102073226B uses metallic potassium as a dehydrating agent to reduce the corrosion of the photoresist stripping solution to the metal layer. However, the generated potassium hydroxide will cause the metal ions in the photoresist stripping solution to seriously exceed the standard, which cannot meet the requirements of the panel and semiconductor fields for the metal ion concentration in the photoresist stripping solution to be lower than 100ppb.

[0006] In addition, US Patent US20140155310A1 introduces a method of reducing the moisture content in photoresist stripping solution by pretreatment. The patent proposes a scheme of adding anhydrous ethanol to tetramethylammonium hydroxide, and then reducing the moisture content in tetramethylammonium hydroxide by vacuum distillation, and further using 3A or 4A molecular sieves to dry organic solvents such as dimethyl sulfoxide, N-methylpyrrolidone, etc., and then using these dry raw materials to prepare photoresist stripping solution, thereby reducing the water content of the photoresist stripping solution to below 1.0%. However, tetramethylammonium hydroxide is easily decomposed into trimethylamine and methanol when heated, and it is very difficult to control the occurrence of side reactions using the vacuum distillation drying process. In order to reduce the moisture content to 1.0%, the addition ratio of desiccants such as molecular sieves is often greater than 30%, and molecular sieves are not selective for water and polar organic solvents. Molecular sieves that adsorb water and a large amount of organic solvents cannot be reused as a solid waste, causing great environmental pollution.

[0007] Therefore, providing a photoresist stripping solution with a small amount of water that has a strong stripping effect and low metal corrosion is a technical problem that needs to be solved urgently by those skilled in the art.

[0008] In view of this, the present invention is proposed. Summary of the invention

[0009] The purpose of the present invention is to provide a photoresist stripping solution, a preparation method and application thereof, aiming to ensure the stripping effect while significantly reducing the corrosiveness to metal layers such as copper, aluminum, silver, tin, tin-silver alloy, etc.

[0010] The present invention is achieved in that:

[0011] In a first aspect, the present invention provides a photoresist stripping solution, which comprises, by weight, 20-60 parts of a bicyclic amidine compound, 1-10 parts of a buffer reagent, and 40-80 parts of an organic solvent;

[0012] Wherein, the bicyclic amidine compound is selected from at least one of 1,5-diazabicyclo[4.3.0]non-5-ene and its derivatives and 1,8-diazabicyclo[5.4.0]undec-7-ene and its derivatives;

[0013] Buffer reagents are used to stabilize the pH value of the system at 9-13.

[0014] In an optional embodiment, the composition comprises 30-50 parts of bicyclic amidine compound, 3-7 parts of buffer reagent and 50-70 parts of organic solvent, by weight.

[0015] In an optional embodiment, the pH value of the buffering agent used to stabilize the system is 10-12.5;

[0016] Preferably, the buffering agent is tris(hydroxymethyl)aminomethane.

[0017] In an optional embodiment, the organic solvent is selected from at least one of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, N-methylformamide, N-methylacetamide, diethylene glycol monomethyl ether and diethylene glycol monobutyl ether;

[0018] In an optional implementation manner, the mass fraction of water in the photoresist stripping solution is below 0.2%.

[0019] In a second aspect, the present invention provides a method for preparing the photoresist stripping solution of any one of the aforementioned embodiments, comprising preparing ingredients according to the composition of the photoresist stripping solution and mixing the components.

[0020] In an optional embodiment, the bicyclic amidine compound, the buffer reagent and the organic solvent are first mixed to obtain the stripping liquid main material, and the stripping liquid main material is mixed with magnesium nitride for reaction; the mass ratio of magnesium nitride to the stripping liquid main material is 0.1-5:100, preferably 0.5-3:100.

[0021] In an optional embodiment, the reaction time between the main material of the stripping liquid and the magnesium nitride is 20-40 minutes;

[0022] Preferably, magnesium nitride is added to the main material of the stripping solution and stirred at a temperature of 20-30° C. for 25-35 minutes.

[0023] In an optional embodiment, after the reaction between the stripping liquid main material and magnesium nitride is completed, filtration is performed to remove the magnesium hydroxide precipitate, ammonia generated by the reaction is removed by a tail gas absorption device, and then filtration and adsorption are performed to remove magnesium ions in the system;

[0024] Preferably, the magnesium hydroxide precipitate is filtered out using a PP or PFA filter with a particle size of 0.05-0.2 μm;

[0025] Preferably, 3M Company's ZP40 is used to remove magnesium ions in the system.

[0026] In a third aspect, the present invention provides the use of the photoresist stripping solution of any one of the aforementioned embodiments or the photoresist stripping solution prepared by any one of the preparation methods of the aforementioned embodiments in the field of semiconductors or panel displays.

[0027] The invention has the following beneficial effects: by improving the organic base composition of the photoresist stripping solution, bicyclic amidine compounds, a buffer reagent and an organic solvent are used as raw materials for preparation, and quaternary ammonium hydroxide is not contained, so that the problems of much photoresist residue on the surface of a wafer or a glass substrate and a high metal corrosion rate caused by high water content of the photoresist stripping solution are effectively avoided; bicyclic amidine compounds such as DBN and DBU are used as organic bases, which have both the performance of a strong base and the effect of an anti-corrosion agent, and the stripping effect is ensured while significantly reducing the corrosion to metal layers such as copper, aluminum, silver, tin, tin-silver alloy and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 A schematic flow chart of a method for removing water from a photoresist stripping solution provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0031] The photoresist stripping solution in the prior art generally contains quaternary ammonium hydroxide, such as tetramethylammonium hydroxide, etc., because the commercially available tetramethylammonium hydroxide is usually a 50% hydrate, which can easily bring water into the photoresist stripping solution.

[0032] In order to solve the problem that quaternary ammonium hydroxide (such as tetramethylammonium hydroxide, etc.) is used as the main raw material of the stripping solution, resulting in a large amount of photoresist residue on the surface of the wafer or glass substrate and a high metal corrosion rate, the inventors improved the main components of the stripping solution. The stripping solution does not contain anti-corrosion agents such as benzotriazole (BTA), polyols, and pyrocatechol, but creatively uses bicyclic amidine compounds as the main components, which have both the properties of a strong base and the effect of an anti-corrosion agent, thereby achieving the dual effects of stripping and resisting metal corrosion. The stripping effect can be guaranteed by using a simple formula composition, and the corrosion to the metal layer is very weak.

[0033] The embodiment of the present invention provides a photoresist stripping solution, which includes 20-60 parts of a bicyclic amidine compound, 1-10 parts of a buffer reagent, and 40-80 parts of an organic solvent by weight. The inventors changed the main components of the stripping solution, combined with a buffer reagent and an organic solvent, the formula is simple, the stripping effect is good, and the corrosion to the metal layer is significantly reduced.

[0034] It should be noted that if the usage ratio of the bicyclic amidine compound, the buffer reagent and the organic solvent exceeds the above range, it is not conducive to obtaining a good stripping effect. By controlling the usage of the three components within the above range, both a good stripping effect and a lower metal layer corrosion can be obtained.

[0035] In a preferred embodiment, the composition comprises 30-50 parts of bicyclic amidine compound, 3-7 parts of buffer reagent and 50-70 parts of organic solvent by weight. Further optimizing the amount of each component can further improve the peeling effect.

[0036] Specifically, the bicyclic amidine compound is selected from at least one of 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) and its derivatives and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and its derivatives, and can be DBN or DBU, or a mixture of the two.

[0037] The chemical formula of DBN is as follows:

[0038]

[0039] The chemical formula of DBU is as follows:

[0040]

[0041] Specifically, the pH value of the buffer used to stabilize the system is 9-13, and the stripping effect of the stripping solution can be guaranteed within this pH range. Preferably, the pH value of the buffer used to stabilize the system is 10-12.5; the buffer is tris (hydroxymethyl)aminomethane (Tris). The buffer not only needs to take into account the pH range, but also requires no metal ion impurities to be introduced, so tris is preferably used.

[0042] Specifically, the organic solvent is selected from at least one of dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-dimethylpropionamide (DMPA), N-methylformamide (NMF), N-methylacetamide (NMA), diethylene glycol monomethyl ether (MDG) and diethylene glycol monobutyl ether (BDG), and is not limited here.

[0043] In some embodiments, the raw materials of the photoresist stripping solution further include magnesium nitride, a bicyclic amidine compound, a buffer reagent and an organic solvent, and the mass ratio of magnesium nitride to the stripping solution main material is 0.1-5: 100, preferably 0.5-3: 100. Adding a small amount of magnesium nitride during the preparation process can react with the water in the stripping solution, significantly reducing the water content of the stripping solution, which is beneficial to reducing corrosion to the metal layer.

[0044] The embodiment of the present invention provides a method for preparing a photoresist stripping solution, wherein ingredients are prepared according to the composition of the photoresist stripping solution, and the components are mixed to prepare a stripping solution comprising a bicyclic amidine compound, a buffer reagent and an organic solvent.

[0045] In order to further reduce the water content of the stripping solution, the bicyclic amidine compound, the buffer reagent and the organic solvent are first mixed to obtain the stripping solution main material, and the stripping solution main material is mixed with magnesium nitride for reaction. Magnesium nitride is used to react with the water in the stripping solution to generate magnesium hydroxide precipitation and ammonia gas, thereby reducing the water content in the photoresist stripping solution. The reaction equation is as follows:

[0046] Mg2N3+6H2O→3Mg(OH)2+2NH3

[0047] In actual operation, please refer to Figure 1 , add high-purity magnesium nitride powder to the main material of the stripping liquid, stir it at a temperature of 20-30°C (i.e., room temperature), and fully stir it in the reactor for 20-40 minutes (such as 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc.) to ensure sufficient reaction; preferably, the stirring time is 25-35 minutes.

[0048] It should be noted that the stirring time can be determined according to the water content to reduce the water content in the photoresist stripping solution to less than 0.2%. After the reaction is completed, the water content in the photoresist stripping solution is sampled and tested. If it is less than 0.2%, the reaction can be stopped. If it is greater than 0.2%, magnesium nitride can be appropriately added to further react until the water content is less than 0.2%.

[0049] Since the reaction involves precipitation and gas generation, the system after the reaction can also be post-treated, specifically including: after the reaction between the stripping liquid main material and magnesium nitride is completed, filtering is performed to remove the magnesium hydroxide precipitate, using a tail gas absorption device to remove the ammonia generated by the reaction, and then filtering and adsorbing are performed to remove the magnesium ions in the system.

[0050] In some embodiments, a PP or PFA filter with a particle size of 0.05-0.2 μm is used to filter out the magnesium hydroxide precipitate, and the generated magnesium hydroxide precipitate is removed by filtering through a filter element.

[0051] In some embodiments, 3M's ZP40 is used to remove magnesium ions in the system. 3M's ZP40 series products are only one way to remove magnesium ions. Obviously, in the embodiments of the present invention, a general ion membrane can be used for filtration and adsorption to remove trace amounts of metal magnesium ions in the photoresist stripping solution to meet the requirements of metal ion impurity content of electronic and semiconductor-grade electronic chemicals.

[0052] In more detail, Figure 1 As shown, an embodiment of the present invention provides a method for removing water from a photoresist stripping solution, comprising the following steps:

[0053] Step S10, adding high-purity magnesium nitride powder into the photoresist stripping solution;

[0054] Step S20, fully stirring to allow magnesium nitride and water to fully react for a certain period of time to reduce the water content in the photoresist stripping solution;

[0055] Step S30, filtering and removing the generated magnesium hydroxide precipitate, and removing the generated ammonia gas through a tail gas absorption device;

[0056] Step S40, using 3M Company's ZP40 series products to absorb trace amounts of metal magnesium ions in the photoresist stripping solution after drying.

[0057] It should be added that the inventors have tried many methods to remove moisture from photoresist stripping liquid, such as: (1) using molecular sieves to remove moisture, which has low adsorption efficiency and poor environmental friendliness; (2) using distillation methods, organic amines and organic bases have the risk of decomposition, complex process control, high energy consumption, and the residual waste liquid is difficult to treat as hazardous waste; (3) using metal magnesium reaction, the reaction controllability is poor. The present application uses magnesium nitride for reaction, which is mild, safe, and environmentally friendly, and is very suitable for removing moisture from the stripping liquid.

[0058] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0059] Example 1

[0060] This embodiment provides a method for preparing a photoresist stripping solution, comprising the following steps:

[0061] The raw materials were weighed according to their mass fractions, and 37 parts of DBN, 3 parts of tris(hydroxymethyl)aminomethane (Tris), and 60 parts of dimethyl sulfoxide (DMSO) were weighed, and the three raw materials were evenly mixed to obtain a stripping solution.

[0062] Embodiment 2-5

[0063] Examples 2-5 all provide a method for preparing a photoresist stripping solution, which differs from Example 1 only in the different formulations, as shown in Table 1:

[0064] Table 1 Formula composition of Examples 1-5

[0065]

[0066] Example 6

[0067] This embodiment provides a method for preparing a photoresist stripping solution, which adopts the formulation of embodiment 1 and comprises the following steps:

[0068] The raw materials were weighed according to their mass fractions, and 37 parts of DBN, 3 parts of tris(hydroxymethyl)aminomethane (Tris), and 60 parts of dimethyl sulfoxide (DMSO) were weighed, and the three raw materials were evenly mixed to obtain a stripping solution.

[0069] Add 0.5g of high-purity magnesium nitride (purchased from Alfa Aesar (China) Chemical Co., Ltd.) to 100mL of mixed stripping solution (tested water content 0.63%); stir at room temperature for 30 minutes, test water content 0.3%, continue to add 0.25g of high-purity magnesium nitride, stir for 20 minutes, and adjust the amount of magnesium nitride to reduce the water content to below 0.2%. Filter and remove the magnesium hydroxide precipitate generated by the reaction through a PP filter with a particle size of 0.1μm to obtain a photoresist stripping solution with a water content of less than 0.2%; use 3M's ZP40 metal ion removal membrane to filter the filtered photoresist stripping solution to adsorb a small amount of magnesium ions, and obtain a photoresist stripping solution with a metal ion content of less than 100ppb.

[0070] Examples 7-10

[0071] Examples 7-10 all provide a method for preparing a photoresist stripping solution. Except for the addition of magnesium nitride, the formula composition of Examples 7-10 is the same as that of Examples 2-5. The specific steps of the preparation method refer to Example 6.

[0072] Comparative Example 1-2

[0073] Comparative Example 1-2 provides a method for preparing an existing photoresist stripping solution, which can be prepared and mixed according to the formula composition in Table 2.

[0074] Table 2 Comparative Examples of Photoresist Stripping Solutions

[0075]

[0076] Comparative Example 3

[0077] The preparation method of a photoresist stripping solution in this comparative example is different from that in Example 6 in that, by mass fraction, the mass fraction of DBN is 15%, that of tris(hydroxymethyl)aminomethane (Tris) is 3%, and that of dimethyl sulfoxide (DMSO) is 82%.

[0078] Comparative Example 4

[0079] The preparation method of a photoresist stripping solution in this comparative example is different from that in Example 6 in that, by mass fraction, the mass fraction of DBN is 65%, that of tris(hydroxymethyl)aminomethane (Tris) is 3%, and that of dimethyl sulfoxide (DMSO) is 32%.

[0080] Comparative Example 5

[0081] Step S1, add 10 g of 4A molecular sieve (purchased from Sinopharm Group, activated at 350° C. for 8 h before use) into 100 mL of photoresist stripping solution (Example 1), and stir at room temperature for 30 min.

[0082] Step S2, filtering and removing the molecular sieve after adsorbing water through a PP filter with a particle size of 0.1 μm.

[0083] Step S3, filtering the filtered photoresist stripping solution using 3M ZP40 metal ion removal membrane to adsorb a small amount of aluminum ions, so as to obtain a photoresist stripping solution with a metal ion content of less than 100 ppb.

[0084] The results showed that the molecular sieve had a poor drying effect, with a water content of up to 0.55% after drying, and a large amount of organic solvents were adsorbed. The volume of the photoresist stripping liquid after filtration was reduced to 90.3 mL.

[0085] Comparative Example 6

[0086] Step S1, add 30 g of 4A molecular sieve (purchased from Sinopharm Group, activated at 350° C. for 8 h before use) into 100 mL of photoresist stripping solution (Example 1), and stir at room temperature for 30 min.

[0087] Step S2, filtering and removing the molecular sieve after adsorbing water through a PP filter with a particle size of 0.1 μm.

[0088] Step S3, filtering the filtered photoresist stripping solution using 3M ZP40 metal ion removal membrane to adsorb a small amount of aluminum ions, so as to obtain a photoresist stripping solution with a metal ion content of less than 100 ppb.

[0089] The results showed that after increasing the amount of molecular sieve used, the drying effect was improved, and the water content was 0.31%, but a large amount of organic solvents were adsorbed, and the volume of the photoresist stripping liquid after filtration was reduced to 78.1 mL.

[0090] Comparative Example 7

[0091] The preparation method of a photoresist stripping liquid in this comparative example is different from that in Example 6 only in that water is removed by vacuum distillation, and the operating parameters are: the vacuum degree is set to 10-12 kPa, the top temperature of the distillation tower is 116°C, and the bottom temperature of the distillation tower is 158°C.

[0092] The results showed that the water content after vacuum distillation was 0.20%, which was roughly the same as the effect of Example 6.

[0093] Test Example 1

[0094] The water content (mass fraction) and metal ion concentration of the stripping solution prepared by the preparation method in Test Examples 1-10 were tested. The water content was tested using a Metrohm 870 moisture meter, and the metal ion concentration was tested using an Agilent ICP-MS 7800. The results are shown in Table 3.

[0095] Table 3 Test results of water content and metal ion concentration

[0096]

[0097]

[0098] It can be seen from the above table results that the use of magnesium nitride in the embodiment of the present invention can effectively reduce the water content in the photoresist stripping solution to less than 0.2%, and the metal ion concentration also meets the use requirements of the semiconductor and panel industries.

[0099] Test Example 2

[0100] In order to further illustrate the application effect of the present invention, a packaged wafer containing a negative dry film with a thickness of 100 μm and exposed and electroplated with bumps (bumping) was immersed in a photoresist stripping solution, stripped for 120 minutes at 65 degrees Celsius, then cleaned with ultrapure water, and finally dried with a spin rinse dryer (SRD) spin rinse dryer, and then the metal corrosion was observed under a scanning electron microscope (SEM). The results are shown in Table 4.

[0101] Table 4 Test results of peeling effect and corrosion of the embodiments and comparative examples

[0102]

[0103]

[0104] It should be noted that the corrosion conditions are divided into no corrosion, slight corrosion and severe corrosion, among which no corrosion means that the metal layer has almost no change; slight corrosion means that the metal layer has some pitting corrosion; severe corrosion means that the metal layer changes color and dense corrosion pits appear. The stripping effect is divided into general, good and excellent, among which general means that there is about 5% residual glue and the product yield is 95%; good means that there is about 2% residual glue and the product yield is 98%; excellent means that there is almost no residual glue and the product yield is above 99.5%.

[0105] It can be seen from Table 4 that in the embodiment of the present invention, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is used to replace TMAH as an organic base for degrading photoresist resin, which can effectively achieve both good stripping effect and good metal corrosion resistance. And as the water content of the photoresist stripping solution decreases, the metal corrosion is further effectively reduced, and the stripping ability is also enhanced.

[0106] In Comparative Example 3, the alkali concentration is too low, which affects the stripping effect; in Comparative Example 4, the organic solvent concentration is too low, resulting in insufficient organic solvent to dissolve the peeled glue, which also leads to a decrease in the stripping effect.

[0107] In summary, the embodiments of the present invention provide a photoresist stripping solution, a preparation method and application thereof. By improving the composition of the photoresist stripping solution and using bicyclic amidine compounds, a buffer reagent and an organic solvent as raw materials for preparation, compared with the prior art, the embodiments of the present invention have the following advantages:

[0108] (1) The micro-water-content photoresist stripping solution of the embodiment of the present invention does not use the traditional quaternary ammonium hydroxide, which effectively avoids the problem of a large amount of photoresist residue on the surface of the wafer or glass substrate and a high metal corrosion rate caused by the high water content of the photoresist stripping solution;

[0109] (2) The micro-water content photoresist stripping solution of the embodiment of the present invention uses bicyclic amidine compounds such as DBN and DBU as organic bases, which have both the performance of a strong base and the effect of an anti-corrosion agent, reduce the complexity of the formula, and are beneficial to the production process control.

[0110] (3) The micro-water content photoresist stripping solution of the embodiment of the present invention uses magnesium nitride as a dehydrating agent, which further reduces the water content of the system, improves the stripping effect and reduces the metal corrosion rate, and has good application and market prospects in the semiconductor field and panel display field.

[0111] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A photoresist stripping solution, characterized in that: The raw materials for preparing the photoresist stripping solution include: a stripping solution main material and magnesium nitride; wherein the stripping solution main material includes, by weight, 30-50 parts of a bicyclic amidine compound, 3-7 parts of a buffer reagent, and 50-70 parts of an organic solvent; the mass ratio of the magnesium nitride to the stripping solution main material is 0.1-5:100; Wherein, the bicyclic amidine compound is selected from at least one of 1,5-diazabicyclo[4.3.0]non-5-ene and its derivatives and 1,8-diazabicyclo[5.4.0]undec-7-ene and its derivatives; The pH value of the buffer reagent used to stabilize the system is 9-13.

2. The photoresist stripping solution according to claim 1, characterized in that The pH value of the buffer reagent used to stabilize the system is 10-12.

5.

3. The photoresist stripping solution according to claim 2, characterized in that: The buffer reagent is tris(hydroxymethyl)aminomethane.

4. The photoresist stripping solution according to claim 1, characterized in that: The organic solvent is selected from at least one of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, N-methylformamide, N-methylacetamide, diethylene glycol monomethyl ether and diethylene glycol monobutyl ether.

5. The photoresist stripping solution according to claim 1, characterized in that: The water content of the photoresist stripping solution is less than 0.2% by mass.

6. A method for preparing the photoresist stripping solution according to any one of claims 1 to 5, characterized in that: Firstly, the bicyclic amidine compound, the buffer reagent and the organic solvent are mixed to obtain a stripping liquid main material, and then the stripping liquid main material is mixed with magnesium nitride for reaction; the mass ratio of the magnesium nitride to the stripping liquid main material is 0.1-5:

100.

7. The preparation method according to claim 6, characterized in that: The mass ratio of the magnesium nitride to the main material of the stripping liquid is 0.5-3:

100.

8. The preparation method according to claim 7, characterized in that: The reaction time of the main material of the stripping liquid and magnesium nitride is 20-40 minutes.

9. The photoresist stripping solution according to claim 8, characterized in that: The magnesium nitride is added to the main material of the stripping solution, and stirred at a temperature of 20-30° C. for 25-35 minutes.

10. The preparation method according to claim 8, characterized in that: After the reaction between the stripping liquid main material and the magnesium nitride is completed, filtration is performed to remove the magnesium hydroxide precipitate, ammonia generated by the reaction is removed by a tail gas absorption device, and then filtration and adsorption are performed to remove magnesium ions in the system.

11. The preparation method according to claim 10, characterized in that: The magnesium hydroxide precipitate is removed by filtering with a PP or PFA filter having a particle size of 0.05-0.2 μm.

12. The preparation method according to claim 11, characterized in that: 3M's ZP40 was used to remove magnesium ions from the system.

13. Use of the photoresist stripping solution according to any one of claims 1 to 5 or the photoresist stripping solution prepared by the preparation method according to any one of claims 6 to 12 in the field of semiconductors or panel displays.

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