A polymer resin for photoresist, a negative photoresist and a recycling method

Abstract

The application discloses a kind of polymer resin for photoresist, negative photoresist and recycling method.The preparation method of polymer resin is: using functional polycarbonate, p-acetyl oxystyrene, initiator, star-shaped RAFT agent to prepare polymer resin.Using 2-benzyl (methyl) amino-9H-thioxanthene-9-ketone, 3-chloropropyl triethoxysilane, potassium carbonate, triethoxysilane compound and 1,1,1,1,3,3,3-hexamethyl disiloxane to prepare photo initiator.Photolithography is compounded by polymer resin, photo initiator and additive, solvent.The negative photoresist has good thermal stability, and can be recycled by specific filter film, and the recovery rate is 79-83%.The application combines chain free volume design and mobility control, and improves the glass transition temperature of material;And photoresist waste liquid can be recycled.The negative photoresist can be used in wafer level advanced packaging, micro-nano processing, high-end optics and other fields.

Description

Technical Field

[0001] This invention relates to a resin material, a photoresist, and a method for recovering the photoresist solution, and more particularly to a polymer resin for photoresist, a negative photoresist, and a method for recovering the photoresist solution. Background Technology

[0002] Photoresist is a key material in semiconductor manufacturing. Negative photoresist is a common photolithography material widely used in chip packaging, microelectronics processing, optoelectronics, and micro / nano fabrication. Its main principle is based on photochemical reactions, where ultraviolet light alters the chemical and physical properties of the photoresist. During exposure, the photosensitizer in the photoresist absorbs light energy and undergoes a chemical reaction, causing changes in the photoresist's solubility or adhesion. These changes can be utilized in subsequent development or etching steps, enabling precise processing of the underlying substrate.

[0003] The preparation of negative photoresists typically involves steps such as adding photosensitizers, selecting solvents, and mixing and homogenizing. Photosensitizers are the core component in the preparation process. They possess the ability to absorb light energy of specific wavelengths and undergo chemical reactions under the influence of light, altering the properties of the photoresist. The selection of photosensitizers is a crucial step in the preparation of negative photoresists, as different photosensitizers have different light absorption characteristics and chemical reaction mechanisms. Common photosensitizers include styrene compounds, epoxy compounds, and propylene oxide. The amount and ratio of photosensitizer added need to be optimized based on specific application requirements and the performance requirements of the photoresist.

[0004] In traditional ultraviolet lithography, the wavelength of light determines the minimum achievable feature size. As the demand for smaller feature sizes grows, technologies such as extreme ultraviolet lithography require higher costs and more complex equipment, increasing the difficulty of fabrication. Photoresists require higher energy and longer exposure times during exposure, leading to increased time costs and adversely affecting the performance of the photosensitizer and resist layer. Prolonged exposure or high-energy light irradiation causes irreversible degradation of photoresist performance, limiting its lifespan and increasing fabrication costs and process control requirements. Furthermore, the waste liquid generated during fabrication, as well as the organic solvents in the photoresist and developer, can cause pollution.

[0005] CN202210476188.1 discloses an alkali-soluble, photosensitive, negative photoresist resin. On one hand, it introduces phenolic hydroxyl monomers and (meth)acrylate monomers to copolymerize and prepare an alkali-soluble resin. On the other hand, it utilizes epoxy groups and carboxyl groups to catalyze ring-opening, introducing polymerizable double bonds into the resin. Combining these two methods, a negative photoresist resin possessing both photosensitivity and alkali solubility is prepared. CN202210160748.2 discloses a method for extreme ultraviolet (EUV) light exposure based on negative photoresist. This method has low production costs, high stability of the exposed pattern, and satisfies the requirement of photochemical reactions under EUV conditions, which is beneficial for mask pattern transfer. However, the photoinitiation efficiency of these two patents has not been adequately studied, and the controllability of the polymerization system viscosity needs further improvement. Furthermore, the recovery and reuse of waste liquid have not been significantly optimized, which may lead to significant pollution and waste in actual processing and production. Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to provide a polymer resin for photoresist with a star-shaped structure and controllable molecular chain movement;

[0007] The second objective of this invention is to provide a negative photoresist with good thermal stability and which can be recycled and reused through a specific filter membrane;

[0008] A third objective of this invention is to provide a method for recycling the aforementioned negative photoresist.

[0009] Technical solution: The polymer resin for photoresist described in this invention has the following structure:

[0010]

[0011] Among them, a~c are 75~95 respectively, d~f are 65~85 respectively, i~k are 45~70 respectively, and l~n are 55~65 respectively;

[0012] R ’ for One of them.

[0013] The above-mentioned method for preparing the polymer resin for photoresist includes the following steps:

[0014] (1) Functional polycarbonate, p-acetoxystyrene, initiator, and star-shaped RAFT agent are mixed in a molar ratio of 55-65:25-35:0.5-1.1:1.2-5.1, and then excess solvent propylene glycol methyl ether acetate is added to obtain a mixture solution; the mixture solution is heated and stirred under vacuum, and then cooled to 0°C; then the mixture solution is dropped into water at a constant speed and stirred, centrifuged and baked to obtain a white slightly yellow resin powder;

[0015] (2) The resin powder and sodium methoxide were dissolved in an alcohol solvent to obtain a polymer solution. The reaction was carried out under heating conditions. After the reaction was completed, the solution was distilled, and then the alcohol solvent was added. After cooling, the polymer solution was dropped into water and stirred. The solution was centrifuged and baked to obtain white polymer resin powder.

[0016] The specific steps are as follows:

[0017] (1) Functional polycarbonate, p-acetoxystyrene, initiator AIBN, and star-shaped RAFT agent CTA were added to a reaction vessel in a molar ratio of 55-65:25-35:0.5-1.1:1.2-5.1, and then excess solvent propylene glycol methyl ether acetate was added. After the reaction vessel was circulated between vacuum and nitrogen three times, the mixture was stirred at 65-70°C for 20-22 h, and then cooled to 0°C and held for 20-30 min. The mixture solution was added dropwise to ultrapure water at a rate of 20-25 mL / h using an automatic liquid adder and stirred at a uniform speed. This process was repeated 3-5 times. After centrifugation, the mixture was baked at 65-75°C overnight to obtain a white slightly yellow resin powder.

[0018] (2) Dissolve white slightly yellow resin powder and sodium methoxide in methanol, react at 75-80℃ for 17-22h, and then distill. After distillation, add an appropriate amount of methanol to the polymer. After the polymer solution cools, use an automatic liquid adder to add the mixture solution dropwise to ultrapure water at a rate of 30-40mL / h and stir at a uniform speed. Repeat 3-5 times, centrifuge, and bake at 80-85℃ overnight to obtain white polymer resin powder.

[0019] The functional polycarbonate in step (1) is prepared by the following steps:

[0020] (1) Dissolve 268-331 molar amounts of trimethylolpropane in an organic solvent at room temperature. Under an inert atmosphere and with stirring, add 629-689 molar amounts of 1,1'-carbonyldiimidazole and continue stirring. After the reaction is complete, filter the mixture, wash the precipitate, and dry it under vacuum to obtain the intermediate product.

[0021] (2) Add 2 to 2.02 moles of intermediate product, 2.02 to 2.23 moles of enol organic compound and excess organic solvent to the reactor, and purge the top space of the reactor with inert gas under stirring conditions; then add acetone solution of bicycloamidine, continue stirring, and evaporate the solvent under inert gas purging; finally add acetic acid / chloroform mixed solution, and obtain crude product by quenching reaction;

[0022] (3) Add the ion exchange resin to the crude product solution, stir and filter out the resin and remove the solvent by rotary evaporation. Dissolve the polymer in dichloromethane and precipitate it overnight in ether at 0-10°C with stirring. Decant the solution and dry it under vacuum to obtain functional polycarbonate.

[0023] The specific steps are as follows:

[0024] (1) Dissolve 268–331 mol of trimethylolpropane in acetone at room temperature and place the solution in a reaction vessel. Divide 629–689 mol of 1,1'-carbonyldiimidazole into 2–3 equal portions and add them to the reaction vessel at a high stirring rate over 30–40 min at room temperature and under a nitrogen atmosphere. After complete addition, stir at room temperature for 18–20 h. Filter to collect the white precipitate and wash it 2–3 times with diethyl ether. Dry under vacuum to obtain the intermediate product.

[0025] (2) Add 2-2.02 moles of intermediate product, 2.02-2.23 moles of enol organic compound and excess acetone to the reaction vessel, and purge the top space of the reaction vessel with nitrogen for 1-2 min under vigorous stirring. Then add an acetone solution containing 25-40% by mass of dicycloamidin to the reaction vessel and stir for 10 min. Evaporate the solvent for 30-45 min under constant nitrogen flow rate. Finally, add an acetic acid / chloroform mixed solution at a rate of 15-25 mL / min and quench the reaction at -4 to 0 °C to obtain the crude product.

[0026] (3) Add excess DOWEX 50WX8H resin to the crude product solution, stir for 5-10 min, filter out the resin and remove the solvent by rotary evaporation, dissolve the polymer in dichloromethane, and precipitate overnight in ether at 0-10℃ with stirring. Decant the solution and vacuum dry to obtain functional polycarbonate.

[0027] The enols include at least one of 10-undecenol, ferulenol, and dihydromyrcenol.

[0028] The negative photoresist of the present invention comprises the following components in parts by weight: 20 parts of the polymer resin of claim 1, 1.5 to 3 parts of photoinitiator, 0.2 to 0.6 parts of additives, and 70 to 90 parts of solvent.

[0029] The photoinitiator is prepared through the following steps:

[0030] (1) Under an inert atmosphere, 2-benzyl(methyl)amino-9H-thioxanth-9-one, 3-chloropropyltriethoxysilane, and potassium carbonate were added to a reactor in a molar ratio of 1-2:1-2.5:2-4. Then, an acetonitrile solution containing 5-10% potassium iodide was added. The reaction was carried out at 80-90°C for 7-9 days. The mixture was filtered and concentrated under vacuum to obtain a viscous crude product. The crude product was purified to obtain a red viscous transparent liquid PI-1.

[0031] (2) PI-1, triethoxysilane compound and 1,1,1,1,3,3,3-hexamethyldisiloxane were added to the reactor in a molar ratio of 1-1.5:5-8:18-21. After adding sufficient water / tetrahydrofuran mixed solution with pH=1-1.5, the mixture was heated to 30-40℃ and stirred for 72-96 hours. Then, dichloromethane was added to dilute the mixture, the pH was adjusted to 7-7.5, and the mixture was distilled under reduced pressure and dried to obtain crude product. The crude product was purified to obtain a red solid powder photoinitiator.

[0032] The triethoxysilane compound includes at least one of methyltriethoxysilane, propyltriethoxysilane, phenyltriethoxysilane, and 3-(methyl)propenoxy-propyltriethoxysilane.

[0033] The specific steps for using the photoinitiator are as follows:

[0034] Under an argon atmosphere, 2-benzyl(methyl)amino-9H-thioxanthracene-9-one, 3-chloropropyltriethoxysilane, and potassium carbonate were added to a reaction vessel in a molar ratio of 1–2:1–2.5:2–4. An acetonitrile solution containing 5–10% potassium iodide was then added, and the reaction was carried out at 80–90°C for 7–9 days. The mixture was filtered and concentrated under vacuum to obtain a viscous crude product. The crude product was purified by silica column chromatography to obtain a red, viscous, transparent liquid, PI-1.

[0035] PI-1, triethoxysilane compound, and 1,1,1,1,3,3,3-hexamethyldisiloxane were added to a reaction vessel in a molar ratio of 1–1.5:5–8:18–21. Sufficient water / tetrahydrofuran (pH 1–1.5) mixed solution of equal volumes was added, and the mixture was heated to 30–40°C and stirred for 72–96 hours. Dichloromethane was then added to dilute the mixture, adjusting the pH to 7–7.5. The mixture was then subjected to vacuum distillation and drying to obtain a crude product. The crude product was purified by silica column chromatography to obtain a red solid powder photoinitiator.

[0036] Furthermore, in the step of preparing the photoinitiator, the triethoxysilane compound includes any one of methyltriethoxysilane, propyltriethoxysilane, phenyltriethoxysilane, and 3-(methyl)propenoxy-propyltriethoxysilane.

[0037] Furthermore, the additive includes a stabilizer and a photolithographic active ingredient. The stabilizer includes any one of sodium ammonium sulfate, sodium ferrous sulfate, and ethylene glycol; the photolithographic active ingredient includes any one of 2-amino-5-chlorobenzamide, N-cyclohexyl-4-chlorobenzamide, benzyl-5-bromo-2-chlorobenzamide, and isopropyl-5-bromo-2-chlorobenzamide.

[0038] Further, the solvent includes any one of the following: a toluene / propylene glycol methyl ether acetate mixture with pH=8.5, a dipropylene glycol methyl ether acetate / propylene glycol mixture with pH=9.5, and an ethylene glycol methyl ether acetate / propylene glycol methyl ether acetate mixture with pH=11.

[0039] The above-mentioned method for recovering photoresist solution from negative photoresist is characterized by comprising the following steps:

[0040] (1) Use a ceramic porous membrane with a pore size of 100-120 nm to filter the developer waste liquid, then add active adsorbent to the filtered developer waste liquid, and mechanically stir and change the color at 50-55℃ for 2-3 hours to obtain pretreated developer waste liquid.

[0041] (2) A waste liquid filter membrane is prepared by arranging 10 to 12 layers of anion exchange membrane and cation exchange membrane alternately, with two adjacent membranes separated by organic brittle light-transmitting spacers and elastic rubber spacers of 1 to 1.5 mm.

[0042] (3) The pretreated developer waste liquid, 0.3-0.32 mol / L sodium sulfate solution and 3.2%-3.5% tetramethylammonium hydroxide are mixed in a volume ratio of 1:0.4-0.5:0.2-0.3 and placed in a vacuum filtration device. The mixture is continuously filtered for 30-45 minutes at room temperature and under an inert atmosphere. The solvent is removed by vacuum distillation at 35-40°C to obtain polymer resin powder. After compounding, photoresist solution can be obtained.

[0043] Furthermore, the specific steps for recycling the photoresist solution are as follows:

[0044] The developer waste liquid was filtered 2-3 times using a ceramic membrane with a pore size of 100-120 nm. Then, 5 g of activated carbon was added to every 0.1 L of developer waste liquid, and the mixture was mechanically stirred and colored at 50-55 °C for 2-3 h to obtain a pretreated developer waste liquid. The ceramic membrane was made of zirconium oxide and had 19-22 channels, an outer diameter of 30 mm, and a length of 1016 mm.

[0045] Waste liquid filter membranes are prepared by alternating 10 to 12 layers of anion exchange membrane JAM-II-07 and cation exchange membrane JCM-II-07, with two adjacent membranes separated by 1 to 1.5 mm plexiglass spacers and silicone rubber.

[0046] The filter membrane is installed in a vacuum filtration device. The pretreated developer waste liquid, 0.3-0.32 mol / L sodium sulfate solution and 3.2%-3.5% tetramethylammonium hydroxide are mixed in a volume ratio of 1:0.4-0.5:0.2-0.3 and then placed in the vacuum filtration device. The mixture is continuously filtered for 30-45 minutes at room temperature and under a nitrogen atmosphere. After 3-5 cycles, the solvent is removed by vacuum distillation at 35-40℃ to obtain polymer resin powder. After compounding, photoresist solution can be obtained.

[0047] Invention Principle: Polymers with a star-shaped structure have more chain ends. The polycarbonate repeating unit on each arm has a higher molecular weight and longer molecular chain segments, reducing the free volume of the chain segments. Furthermore, the star structure spatially restricts the chain mobility of each segment, thereby increasing the glass transition temperature. Sodium methoxide, after deprotecting the acetyl groups, generates a large number of free hydroxyl groups. These hydroxyl groups form extensive hydrogen bonds with the ester groups, compressing the movement of the molecular chain segments and further increasing the glass transition temperature. The introduced polycarbonate repeating unit segments have low molecular regularity and weak symmetry, and the introduction of long-chain enol branches reduces their crystallinity, resulting in smaller crystal nuclei and improved light transmittance of the material.

[0048] The prepared photoinitiator exhibits high photochemical efficiency and contains more stable Si-O-Si units in its molecular chain segments. These units have the ability to absorb excess heat energy, thereby reducing the thermal decomposition rate. The photoresist initiated by it exhibits high thermal stability due to the higher crosslinking density brought about by the methacrylate groups at the crosslinking points in the initiator. When using the initiator for negative photoresist curing, the film's resistance to polar solvents is greatly improved, attributed to the low surface energy and low polarity of the Si-O-Si segments. Due to the increased crosslinking density in the material, the film initiated by the methacrylate groups serving as crosslinking points exhibits optimal resistance to polar solvents, which is beneficial for photoresist elution.

[0049] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects:

[0050] 1. The polymer resin of the present invention has a star-shaped structure with more chain ends. The polycarbonate repeating unit on each arm has a higher molecular weight and a longer molecular chain segment, which reduces the free volume of the chain segment. Furthermore, the star-shaped structure further restricts the chain mobility of each chain segment in space, thereby increasing the glass transition temperature of the molecule.

[0051] 2. The prepared photoinitiator exhibits high photochemical efficiency and low thermal decomposition rate. The photoresist it initiates possesses high thermal stability and is beneficial for photoresist elution.

[0052] 3. The prepared photoresist can be eluted with water and ethanol. The decomposition sites are located in the polycarbonate segments of the polymer. Utilizing the polar hydroxyl and ester groups distributed in the segments, the photoresist solution can be rapidly dissolved, reducing pattern edge roughness. Simultaneously, the adhesion between the photoresist and the silicon substrate surface is enhanced, protecting the substrate surface during subsequent etching processes. Furthermore, the unexposed photoresist dissolved in the solvent can be recovered through vacuum distillation, reducing usage costs.

[0053] 4. The recovered developer was vacuum concentrated to remove the negative photoresist, verifying its recyclability. After recovery, evaporation, drying, and structural analysis, the results showed that the photoresist resin recovery rate reached 79-83%. The recovered resin molecular chain structure remained stable. The initial degradation temperature of the photoresist solution decreased by 3.2%, the degradation temperature decreased by 2.7%, and the initial degradation temperature of the cured photoresist film decreased by 5.5% and the degradation temperature decreased by 6.1%. The glass transition temperature decreased by 4.4%, and the overall thermal performance of the photoresist showed only a small decrease. Furthermore, after three to five cycles of testing, the photoresist could be recycled to obtain patterns with approximately the same resolution. Therefore, the negative photoresist extracted from the developer can be recycled and reused.

[0054] 5. Other key indicators of the photoresist film prepared by this invention include: ① Viscosity: 3400~4200mPa·s; ② Metal ions: ≤3ppm; ③ Single coating thickness: 55μm; Double coating thickness: 122μm; ④ Film retention rate: >97%; ⑤ Uniformity: 3.5%; ⑥ Exposure energy: 700~1200mJ / cm 2 .

[0055] 6. The negative photoresist prepared by this invention is mainly used in wafer-level advanced packaging, semiconductor manufacturing, micro-nano processing, OLED display, high-end optics and other fields. Attached Figure Description

[0056] Figure 1 Infrared curves of the polymers in Examples 1-3;

[0057] Figure 2 The scanning electron microscope image and thermogravimetric curve of Example 1 are shown below.

[0058] Figure 3 The scanning electron microscope image and thermogravimetric curve of Example 2 are shown below.

[0059] Figure 4 The scanning electron microscope image and thermogravimetric curve of Example 3 are shown below;

[0060] Figure 5 The image shows a scanning electron microscope image and a thermogravimetric curve for Comparative Example 1.

[0061] Figure 6The image shown is a scanning electron microscope image and a thermogravimetric curve for Comparative Example 2. Detailed Implementation

[0062] The present invention will now be described in further detail.

[0063] Example 1

[0064] (I) Preparation of functional polycarbonate:

[0065] 3.144 g of trimethylolpropane was dissolved in acetone at room temperature and placed in a reaction vessel. 7.898 g of 1,1'-carbonyldiimidazole was divided into two equal portions and added to the reaction vessel at a high stirring rate over 30 min at room temperature and under a nitrogen atmosphere. After complete addition, the mixture was stirred at room temperature for 18 h. The white precipitate was collected by filtration and washed twice with diethyl ether. The precipitate was then dried under vacuum to obtain the intermediate product.

[0066] Add 5.144 g of intermediate product, 2.165 g of 10-undecenol, and excess acetone to a reaction vessel. Purge the top space of the reaction vessel with nitrogen for 1 min under vigorous stirring. Then, add an acetone solution containing 25% (w / w) dicycloamidin to the reaction vessel and stir for 10 min. Evaporate the solvent for 30 min under constant nitrogen flow rate. Finally, add an acetic acid / chloroform mixture at a rate of 15 mL / min and quench the reaction at -4 °C to obtain the crude product.

[0067] Excess DOWEX 50WX8H resin was added to the crude product solution, stirred for 5 minutes, the resin was filtered off and the solvent was removed by rotary evaporation. The polymer was dissolved in dichloromethane and precipitated overnight in ether at 0°C with stirring. The solution was decanted and dried under vacuum to obtain functional polycarbonate.

[0068] (II) Preparation of polymer resin:

[0069] The above-mentioned functional polycarbonate, p-acetoxystyrene, initiator AIBN, and star-shaped RAFT agent CTA were added to a reaction vessel in a molar ratio of 55:25:0.5:1.2, followed by the addition of excess solvent propylene glycol methyl ether acetate. The reaction vessel was circulated between vacuum and nitrogen three times. The mixture was then stirred at 65°C for 20 hours, followed by cooling to 0°C and holding for 20 minutes. Using an automatic dispensing device, the mixture was added dropwise to ultrapure water at a rate of 20 mL / h with uniform stirring. This process was repeated three times. The mixture was then centrifuged and baked at 65°C overnight to obtain a white, slightly yellow resin powder.

[0070] White, slightly yellow resin powder and sodium methoxide were dissolved in methanol and reacted at 75°C for 17 hours, followed by distillation. After distillation, an appropriate amount of methanol was added to the polymer. After the polymer solution cooled, the mixture was added dropwise to ultrapure water at a rate of 30 mL / h using an automatic liquid dispenser while stirring at a uniform speed. This process was repeated three times. The mixture was then centrifuged and baked at 80°C overnight to obtain white polymer resin powder.

[0071] (III) Preparation of photoinitiators:

[0072] Under an argon atmosphere, 2-benzyl(methyl)amino-9H-thioxanthracene-9-one, 3-chloropropyltriethoxysilane, and potassium carbonate were added to a reaction vessel in a molar ratio of 1:1:2. An acetonitrile solution containing 5% potassium iodide was then added, and the reaction was carried out at 80°C for 7 days. The mixture was filtered and concentrated under vacuum to obtain a viscous crude product. The crude product was purified by silica column chromatography to obtain a red, viscous, transparent liquid, PI-1.

[0073] PI-1, methyltriethoxysilane, and 1,1,1,1,3,3,3-hexamethyldisiloxane were added to a reaction vessel in a molar ratio of 1:5:18. Sufficient water / tetrahydrofuran (pH=1) mixed solution of equal volumes was added, and the mixture was heated to 30°C and stirred for 72 hours. Dichloromethane was then added to dilute the mixture, the pH was adjusted to 7, and the mixture was distilled under reduced pressure and dried to obtain a crude product. The crude product was purified by silica column chromatography to obtain a red solid powder photoinitiator.

[0074] (iv) Preparation of photoresist:

[0075] A photoresist was prepared by mixing equal volumes of 10g polymer resin, 0.751g photoinitiator, 0.064g sodium ammonium sulfate, 0.312g 2-amino-5-chlorobenzamide, and 55g toluene / propylene glycol methyl ether acetate at pH 8.5.

[0076] (v) Photoresist recycling:

[0077] After photolithography, the developer waste liquid was filtered twice using a ceramic membrane with a pore size of 100nm. Then, 5g of activated carbon was added to every 0.1L of developer waste liquid, and the mixture was mechanically stirred and colored at 50℃ for 2 hours to obtain pretreated developer waste liquid.

[0078] Waste liquid filter membranes were prepared by arranging 10 layers of anion exchange membrane JAM-II-07 and cation exchange membrane JCM-II-07 alternately, with two adjacent membranes separated by 1 mm plexiglass spacers and silicone rubber.

[0079] The filter membrane was installed in a vacuum filtration device. The pretreated developer waste liquid, 0.3 mol / L sodium sulfate solution and 3.2% tetramethylammonium hydroxide were mixed in a volume ratio of 1:0.4:0.2 and then placed in the filtration device. The mixture was continuously filtered for 30 minutes at room temperature and under a nitrogen atmosphere. After three cycles, the solvent was removed by vacuum distillation at 35°C to obtain polymer resin powder. After compounding, photoresist solution can be obtained.

[0080] from Figure 2 As can be seen from (a) above, the photoresist cured well. Figure 2 As shown in (b), the glass transition temperature is 238℃, and the degradation temperature is 374℃. The photoresist film has a transmittance of 98.1%, a recovery rate of 80%, and a thermal property change rate of 3.2%.

[0081] like Figure 1 As shown, in the infrared curve before alcoholysis: 1763 cm⁻¹ -1 The C=O vibration peak representing p-acetoxystyrene is 1719 cm⁻¹. -1 The C=O vibration peak representing functional polycarbonate, 10¹² cm⁻¹ -1 and 911cm -1 The CO vibration peak representing p-acetoxystyrene;

[0082] In the infrared curve after alcoholysis: in addition to the characteristic peaks before alcoholysis mentioned above, the peak at 3500 cm⁻¹ is also present. -1 The characteristic peak representing the -OH group generated by alcoholysis indicates that the target polymer was successfully synthesized.

[0083] Example 2

[0084] (I) Preparation of functional polycarbonate:

[0085] 5.168 g of trimethylolpropane was dissolved in acetone at room temperature and placed in a reaction vessel. 8.721 g of 1,1'-carbonyldiimidazole was divided into two equal portions and added to the reaction vessel at a high stirring rate over 35 min at room temperature and under a nitrogen atmosphere. After complete addition, the mixture was stirred at room temperature for 19 h. The white precipitate was collected by filtration and washed twice with diethyl ether. The precipitate was then dried under vacuum to obtain the intermediate product.

[0086] Add 4.446 g of intermediate product, 8.154 g of ferulenol, and excess acetone to a reaction vessel. Purge the top space of the reaction vessel with nitrogen for 1 min under vigorous stirring. Then, add an acetone solution containing 30% (w / w) dicycloamidin to the reaction vessel and stir for 10 min. Evaporate the solvent for 35 min under constant nitrogen flow rate. Finally, add an acetic acid / chloroform mixture at a rate of 20 mL / min and quench the reaction at -2 °C to obtain the crude product.

[0087] Excess DOWEX 50WX8H resin was added to the crude product solution, stirred for 8 minutes, the resin was filtered off and the solvent was removed by rotary evaporation. The polymer was dissolved in dichloromethane and precipitated overnight in stirred diethyl ether at 5°C. The solution was decanted and vacuum dried to obtain functional polycarbonate.

[0088] (II) Preparation of polymer resin:

[0089] Functional polycarbonate, p-acetoxystyrene, initiator AIBN, and star-shaped RAFT agent CTA were added to a reactor in a molar ratio of 60:30:0.8:3, followed by excess solvent propylene glycol methyl ether acetate. The reactor was circulated between vacuum and nitrogen three times. The mixture was stirred at 70°C for 21 hours, then cooled to 0°C and held for 25 minutes. Using an automatic dispensing device, the mixture was added dropwise to ultrapure water at a rate of 25 mL / h with uniform stirring. This process was repeated four times. The mixture was then centrifuged and baked at 70°C overnight to obtain a white, slightly yellow resin powder.

[0090] White, slightly yellow resin powder and sodium methoxide were dissolved in methanol and reacted at 78°C for 19 hours, followed by distillation. After distillation, an appropriate amount of methanol was added to the polymer. After the polymer solution cooled, the mixture was added dropwise to ultrapure water at a rate of 35 mL / h using an automatic adder while stirring at a uniform speed. This process was repeated four times. The mixture was then centrifuged and baked at 85°C overnight to obtain white polymer resin powder.

[0091] (III) Preparation of photoinitiators:

[0092] Under an argon atmosphere, 2-benzyl(methyl)amino-9H-thioxanthracene-9-one, 3-chloropropyltriethoxysilane, and potassium carbonate were added to a reaction vessel in a molar ratio of 1.5:2:3. An acetonitrile solution containing 7% potassium iodide was then added, and the reaction was carried out at 85°C for 8 days. The mixture was filtered and concentrated under vacuum to obtain a viscous crude product. The crude product was purified by silica column chromatography to obtain a red, viscous, transparent liquid, PI-1.

[0093] PI-1, phenyltriethoxysilane, and 1,1,1,1,3,3,3-hexamethyldisiloxane were added to a reaction vessel in a molar ratio of 1.2:7:19. Sufficient water / tetrahydrofuran (pH=1) mixed solution of equal volumes was added, and the mixture was heated to 35°C and stirred for 80 hours. Dichloromethane was then added to dilute the mixture, the pH was adjusted to 7, and the product was obtained by vacuum distillation and drying. The crude product was purified by silica column chromatography to obtain a red solid powder photoinitiator.

[0094] (iv) Preparation of photoresist:

[0095] A photoresist was prepared by mixing 15g of polymer resin, 0.833g of photoinitiator, 0.179g of sodium ferrous sulfate, 0.121g of N-cyclohexyl-4-chlorobenzamide, and 75g of a mixed solution of dipropylene glycol methyl ether acetate / propylene glycol at pH 9.5 in equal volumes.

[0096] (v) Photoresist recycling:

[0097] After photolithography, the developer waste liquid was filtered three times using a ceramic membrane with a pore size of 110 nm. Then, 5 g of activated carbon was added to every 0.1 L of developer waste liquid, and the mixture was mechanically stirred and colored at 50 °C for 2.5 h to obtain pretreated developer waste liquid.

[0098] An 11-layer alternating layer of anion exchange membrane JAM-II-07 and cation exchange membrane JCM-II-07 was used, with two adjacent membranes separated by a 1mm plexiglass spacer and silicone rubber, to prepare a waste liquid filter membrane.

[0099] The filter membrane was installed in a vacuum filtration device. The pretreated developer waste liquid, 0.31 mol / L sodium sulfate solution and 3.4% tetramethylammonium hydroxide were mixed in a volume ratio of 1:0.45:0.25 and then placed in the filtration device. The mixture was continuously filtered for 35 minutes at room temperature and under a nitrogen atmosphere. After 4 cycles, the solvent was removed by vacuum distillation at 40°C to obtain polymer resin powder. After compounding, photoresist solution can be obtained.

[0100] from Figure 3 As can be seen from (a) above, the photoresist cured well. Figure 3 As shown in (b), the glass transition temperature is 271℃, and the degradation temperature is 386℃. The photoresist film has a transmittance of 97.4%, a recovery rate of 82%, and a thermal property change rate of 3.7%.

[0101] Example 3

[0102] (I) Preparation of functional polycarbonate:

[0103] 3.184 g of trimethylolpropane was dissolved in acetone at room temperature and placed in a reaction vessel. 7.667 g of 1,1'-carbonyldiimidazole was divided into three equal portions and added to the reaction vessel at a high stirring rate over 40 min at room temperature and under a nitrogen atmosphere. After complete addition, the mixture was stirred at room temperature for 20 h. The white precipitate was collected by filtration and washed three times with diethyl ether. The precipitate was then dried under vacuum to obtain the intermediate product.

[0104] 2.887 g of intermediate product, 4.875 g of dihydromyrcene alcohol, and excess acetone were added to a reaction vessel. The top space of the reaction vessel was purged with nitrogen for 2 min under vigorous stirring. Then, an acetone solution containing 40% dicycloamidin was added to the reaction vessel and stirred for 10 min. The solvent was evaporated for 45 min under constant nitrogen flow rate. Finally, an acetic acid / chloroform mixed solution was added at a rate of 25 mL / min, and the reaction was quenched at 0 °C to obtain the crude product.

[0105] Excess DOWEX 50WX8H resin was added to the crude product solution, stirred for 10 min, the resin was filtered off and the solvent was removed by rotary evaporation. The polymer was dissolved in dichloromethane and precipitated overnight in stirred ether at 10 °C. The solution was decanted and dried under vacuum to obtain functional polycarbonate.

[0106] (II) Preparation of polymer resin:

[0107] Functional polycarbonate, p-acetoxystyrene, initiator AIBN, and star-shaped RAFT agent CTA were added to a reaction vessel in a molar ratio of 65:35:1.1:5.1, followed by excess solvent propylene glycol methyl ether acetate. The reaction vessel was circulated between vacuum and nitrogen three times. The mixture was then stirred at 70°C for 22 hours, followed by cooling to 0°C and holding for 30 minutes. Using an automatic adder, the mixture was added dropwise to ultrapure water at a rate of 25 mL / h with uniform stirring. This process was repeated five times. The mixture was then centrifuged and baked at 75°C overnight to obtain a white, slightly yellow resin powder.

[0108] White, slightly yellow resin powder and sodium methoxide were dissolved in methanol and reacted at 80°C for 22 hours, followed by distillation. After distillation, an appropriate amount of methanol was added to the polymer. After the polymer solution cooled, the mixture was added dropwise to ultrapure water at a rate of 40 mL / h using an automatic liquid dispenser while stirring at a uniform speed. This process was repeated 5 times. The mixture was then centrifuged and baked at 85°C overnight to obtain white polymer resin powder.

[0109] (III) Preparation of photoinitiators:

[0110] Under an argon atmosphere, 2-benzyl(methyl)amino-9H-thioxanthracene-9-one, 3-chloropropyltriethoxysilane, and potassium carbonate were added to a reaction vessel in a molar ratio of 2:2.5:4. An acetonitrile solution containing 10% potassium iodide was then added, and the reaction was carried out at 90°C for 9 days. The mixture was filtered and concentrated under vacuum to obtain a viscous crude product. The crude product was purified by silica column chromatography to obtain a red, viscous, transparent liquid, PI-1.

[0111] PI-1, 3-(meth)propoxypropyltriethoxysilane, and 1,1,1,1,3,3,3-hexamethyldisiloxane were added to a reaction vessel in a molar ratio of 1.5:8:21. Sufficient water / tetrahydrofuran (pH 1.5) mixed solution of equal volumes was added, and the mixture was heated to 40°C and stirred for 96 hours. Dichloromethane was then added to dilute the mixture, the pH was adjusted to 7.5, and the mixture was distilled under reduced pressure and dried to obtain a crude product. The crude product was purified by silica column chromatography to obtain a red solid powder photoinitiator.

[0112] (iv) Preparation and recycling of photoresist:

[0113] A photoresist was prepared by mixing equal volumes of 21g polymer resin, 0.722g photoinitiator, 0.173g ethylene glycol, 0.214g isopropyl 5-bromo-2-chlorobenzamide, and 84g ethylene glycol methyl ether acetate / propylene glycol methyl ether acetate solution at pH=11.

[0114] After photolithography, the developer waste liquid was filtered three times using a ceramic membrane with a pore size of 120nm. Then, 5g of activated carbon was added to every 0.1L of developer waste liquid, and the mixture was mechanically stirred and colored at 55℃ for 3 hours to obtain pretreated developer waste liquid.

[0115] Waste liquid filter membranes were prepared by alternating 12 layers of anion exchange membrane JAM-II-07 and cation exchange membrane JCM-II-07, with two adjacent membranes separated by 1.5 mm plexiglass spacers and silicone rubber.

[0116] The filter membrane was installed in a vacuum filtration device. The pretreated developer waste liquid, 0.32 mol / L sodium sulfate solution and 3.4% tetramethylammonium hydroxide were mixed in a volume ratio of 1:0.5:0.3 and then placed in the filtration device. The mixture was continuously filtered for 45 min at room temperature and under a nitrogen atmosphere. After 5 cycles, the solvent was removed by vacuum distillation at 40 °C to obtain polymer resin powder. After compounding, photoresist solution can be obtained.

[0117] from Figure 4 As can be seen from (a) above, the photoresist cured well. Figure 4 As shown in (b), the glass transition temperature is 269℃, and the degradation temperature is 382℃. The photoresist film has a transmittance of 98.3%, a recovery rate of 83%, and a thermal property change rate of 2.2%.

[0118] Compare with Example 1

[0119] The difference from Example 1 is that no photolithography active ingredient was added.

[0120] from Figure 5 As can be seen from (a) above, the photoresist curing is generally good, and a small number of uneven protrusions appear on the film surface. Figure 5As shown in (b), the glass transition temperature is 231℃, and the degradation temperature is 360℃. The photoresist film has a transmittance of 94.2%, a recovery rate of 74%, and a thermal property change rate of 7.4%.

[0121] Compare with Example 2

[0122] The difference from Example 2 is that 1173 photoinitiator is used.

[0123] from Figure 6 As can be seen from (a) above, the photoresist has poor curing, and the film surface is rough and uneven. Figure 6 As shown in (a), the glass transition temperature is 243℃, and the degradation temperature is 347℃. The photoresist film has a transmittance of 91.4%, a recovery rate of 71%, and a thermal property change rate of 9.1%.

[0124] The molecular weight and dispersibility index of the polymer resin under different CTA feed ratios are shown in Table 1 below.

[0125] Table 1. Molecular weight and dispersibility index of polymer resins at different CTA feed ratios.

[0126] Serial Number <![CDATA[Weight-average molecular weight (×10 3 g / mol)]]> Dispersion Index 1 123.03 1.43 2 28.88 1.59 3 16.32 1.44 4 12.91 1.26 5 10.52 1.32

[0127] Five groups of polymer resins were prepared according to CTA injection molar ratios of 0, 1.2, 2.5, 3.8, and 5.1, respectively. The weight-average molecular weight and dispersibility index were measured by GPC analysis. Molecular weight has a significant impact on the coating uniformity of the photoresist solution.

[0128] The main methods used in this invention for analyzing the thermal stability of photoresist are thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The initial degradation temperature (T5) and 5% weight loss temperature of the photoresist can reach 211–275°C, and the degradation temperature (T...)... 50 The photoinitiator exhibits a 50% weight loss and can reach temperatures of 330–355°C. Simultaneously, it contains a small amount of cyclic organosilicon compounds, which possess high thermal stability, and the photoinitiator decomposition temperature is sufficiently high to meet the requirements for high-temperature applications. Thermogravimetric analysis of the cured photoresist film revealed that the T5 of the photoresist film prepared with the aforementioned photoinitiator increased by 20–39°C compared to the uncured film. 50 Increase the temperature by 30–49°C. The photoresist film polymerized using an initiator containing methacrylate groups exhibits T5 and T6... 50 The increases were the most significant, rising by 39°C and 49°C respectively. This is mainly due to the high photoinitiator's high photochemical efficiency, the stable Si-O-Si units after curing (which absorb excess heat), and the higher crosslinking density resulting from the methacrylate groups. The glass transition temperature Tg of the cured film was determined using differential scanning calorimetry. gThe T-phase of the photoresist film initiated by the photoinitiator. g The value is approximately 238–269℃, and T increases with increasing photoinitiator content. g The value first decreased and then increased.

Claims

1. A polymer resin for photoresist, characterized in that, The polymer resin has the following structure: ； Among them, a~c are 75~95 respectively, d~f are 65~85 respectively, i~k are 45~70 respectively, and l~n are 55~65 respectively; R ’ for One of them.

2. A method for preparing the polymer resin for photoresist according to claim 1, characterized in that, Includes the following steps: (1) Functional polycarbonate, acetoxystyrene, initiator, and star-shaped RAFT agent are mixed in a molar ratio of 55~65:25~35:0.5~1.1:1.2~5.1, and then excess solvent propylene glycol methyl ether acetate is added to obtain a mixture solution; the mixture solution is heated and stirred under vacuum, and then cooled to 0°C; then the mixture solution is dropped into water at a constant speed and stirred, centrifuged and baked to obtain a white slightly yellow resin powder; (2) The resin powder and sodium methoxide were dissolved in an alcohol solvent to obtain a polymer solution. The reaction was carried out under heating conditions. After the reaction was completed, the solution was distilled, and then the alcohol solvent was added. After cooling, the polymer solution was dropped into water and stirred. After centrifugation and baking, white polymer resin powder was obtained.

3. The method for preparing the polymer resin for photoresist according to claim 2, characterized in that, In step (1), the mixture is stirred at 65~70℃ for 20~22 h, and then cooled to 0℃ and held for 20~30 min; in step (2), the mixture is reacted at 75~80℃ for 17~22 h and then distilled.

4. The method for preparing the polymer resin for photoresist according to claim 2, characterized in that, The functional polycarbonate is prepared by the following steps: (1) Dissolve 268-331 molar amounts of trimethylolpropane in an organic solvent at room temperature. Under an inert atmosphere and with stirring, add 629-689 molar amounts of 1,1'-carbonyldiimidazole and continue stirring. After the reaction is complete, filter the mixture, wash the precipitate, and dry it under vacuum to obtain the intermediate product. (2) Add 2-2.02 molar parts of intermediate product, 2.02-2.23 molar parts of enol organic compound and excess organic solvent to the reactor, and purge the top space of the reactor with inert gas under stirring conditions; then add acetone solution of bicycloamidine, continue stirring, and evaporate the solvent under inert gas purging; finally add acetic acid / chloroform mixed solution, and obtain crude product by quenching reaction; (3) Add the ion exchange resin to the crude product solution, stir and filter out the resin and remove the solvent by rotary evaporation. Dissolve the polymer in dichloromethane and precipitate it overnight in ether at 0~10℃ with stirring. Decant the solution and dry it under vacuum to obtain functional polycarbonate.

5. The method for preparing the polymer resin for photoresist according to claim 4, characterized in that, The enols include at least one of 10-undecenol, ferulenol, and dihydromyrcenol.

6. The method for preparing the polymer resin for photoresist according to claim 4, characterized in that, In step (1), 629 to 689 molar amounts of 1,1'-carbonyldiimidazole are divided into 2 to 3 equal parts and added one part at a time over 30 to 40 minutes under an inert atmosphere. After complete addition, the mixture is stirred at room temperature for 18 to 20 hours.

7. A negative photoresist, characterized in that, The product comprises the following components in parts by weight: 20 parts of the polymer resin as described in claim 1, 1.5 to 3 parts of the photoinitiator, 0.2 to 0.6 parts of the additive, and 70 to 90 parts of the solvent.

8. The negative photoresist according to claim 7, characterized in that, The photoinitiator is prepared by the following steps: (1) Under an inert atmosphere, 2-benzyl(methyl)amino-9H-thioxanth-9-one, 3-chloropropyltriethoxysilane, and potassium carbonate were added to a reactor in a molar ratio of 1~2:1~2.5:2~4. Then, an acetonitrile solution containing 5~10% potassium iodide was added. The reaction was carried out at 80~90℃ for 7~9 days. The mixture was filtered and vacuum concentrated to obtain a viscous crude product. The crude product was purified to obtain a red viscous transparent liquid PI-1. (2) PI-1, triethoxysilane compound and 1,1,1,1,3,3,3-hexamethyldisiloxane were added to the reactor in a molar ratio of 1~1.5:5~8:18~21. After adding sufficient water / tetrahydrofuran mixed solution with pH=1~1.5, the mixture was heated to 30~40℃ and stirred for 72~96 h. Then, dichloromethane was added to dilute the mixture, the pH was adjusted to 7~7.5, and the mixture was distilled under reduced pressure and dried to obtain crude product. The crude product was purified to obtain a red solid powder photoinitiator.

9. The negative photoresist according to claim 8, characterized in that, The triethoxysilane compound includes at least one of methyltriethoxysilane, propyltriethoxysilane, phenyltriethoxysilane, and 3-(methyl)propenoxy-propyltriethoxysilane.

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