ESCAP resin as well as preparation method and application thereof

Abstract

The invention provides ESCAP resin as well as a preparation method, a purification method and application thereof, and the preparation method of the ESCAP resin comprises the following steps: 4-acetoxystyrene and tert-butyl acrylate are subjected to ATRP (Atom Transfer Radical Polymerization) reaction under the action of a catalyst, a complexing agent and an initiator to obtain a prepolymer, and the prepolymer is subjected to ammonolysis to obtain the ESCAP resin. The ESCAP resin prepared through the ATRP reaction has a low molecular weight distribution index, the total metal ion content of the ESCAP resin can be reduced to 100 ppb or below after purification, and the metal ion content of the ESCAP resin can be reduced to 10 ppb or below.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer synthesis, in particular to an ESCAP resin and a preparation method and application thereof. Background Art

[0002] Photoresist is a corrosion-resistant thin film material whose solubility changes significantly in areas exposed to ultraviolet light, electron beams, ion beams, or X-rays. Photoresist is widely used in the manufacturing processes of semiconductor devices, printed circuit boards, color filters, and micro-electromechanical systems. Generally, photoresist is composed of a film-forming resin, a photoinitiator, a solvent, and other additives. The film-forming resin serves as the backbone material and is particularly important in determining the performance of the photoresist. In the semiconductor industry, miniaturization by reducing the minimum feature size of the chip has become the main way to simultaneously enhance the performance of semiconductor devices and reduce costs. Because the resolution of the photoresist is proportional to the wavelength (λ) of the exposure light source and inversely proportional to the numerical aperture (NA) of the exposure machine, shortening the wavelength of the exposure light source has become a major focus of the development of photolithography technology.

[0003] With the introduction of chemically amplified photoresist technology, exposure wavelengths have advanced from ultraviolet to single-wavelength G-line (436nm), I-line (365nm), deep ultraviolet (248nm, 193nm), and extreme ultraviolet (13.5nm). As exposure wavelengths continue to decrease, higher requirements are placed on the composition of photoresists, and researchers are striving to develop photoresist resins suitable for specific wavelengths. The ESCAP resin, first developed by IBM, consists of a copolymer of p-hydroxystyrene and t-butyl acrylate. This resin structure offers several advantages: the t-butyl groups in the copolymer exhibit improved thermal stability, enabling higher prebake temperatures; and after acid-catalyzed deprotection, the t-butyl groups convert to carboxyl groups, resulting in faster dissolution of the ESCAP resin in the developer. This faster dissolution rate helps improve the contrast of the photoresist. Consequently, the polymer of p-hydroxystyrene and t-butyl acrylate has become the primary material used in 248nm photoresist resins.

[0004] Currently, photoresist resins are mostly synthesized by atom transfer radical polymerization (ATRP). Macromol Rapid Commun. 1997.18.1095 disclosed the synthesis of poly (4-acetoxystyrene) by ATRP, with a PDI of 1.11-1.18; Macromol Rapid Commun. 2000.21.98 disclosed the preparation of poly (4-acetoxystyrene-b-styrene-b-isobutylene) by ATRP, with a PDI of 1.22-1.68; Polymer. 2022.249.124853 disclosed the synthesis of PS-b-PMMa block copolymers used as photoresist resins by ATRP alone, with a PDI of 1.09-1.42. J Appl Polym Sci. 2020.137.49416. disclosed the synthesis of PS-b-PMMA block copolymers by ATRP and NMP, with a PDI of 1.10. However, photoresist resins synthesized by ATRP have not yet been industrialized. This is mainly because the introduction of metal inorganic salts during the polymerization process results in a high content of metal ions in the photoresist resin and is difficult to remove. In the semiconductor industry, the metal ion content in the photoresist resin needs to be less than 100 ppb.

[0005] Macromol Rapid Commun.2015.36.1702. and Prog Polym Sci.2004.29.1053. disclose the removal of Cu from polymers prepared by ATRP. 2+ Several methods have been proposed, including liquid-liquid biphasic systems, supported catalyst systems, and post-purification methods. However, polymerization in liquid-liquid biphasic systems is more difficult to control than in homogeneous systems because the catalyst in one phase has limited contact with the growing polymer chains in the other phase. In various supported catalyst systems, the synthesis of the required catalyst supports is complex, making large-scale production difficult. Post-purification methods require large amounts of solvents or absorbents, resulting in high costs and polymer loss. Furthermore, none of the aforementioned methods can reduce the total metal ion concentration in ATRP-produced polymers to below 100 ppb. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide an ESCAP resin and a preparation method and use thereof, so as to solve the problems in the prior art.

[0007] To achieve the above-mentioned purpose and other related purposes, the present invention is achieved through the following technical solutions.

[0008] One of the objectives of the present invention is to disclose a method for preparing an ESCAP resin, which comprises the following steps: subjecting 4-acetoxystyrene and tert-butyl acrylate to an ATRP reaction in the presence of a catalyst, a complexing agent, and an initiator to obtain a prepolymer, and aminolyzing the prepolymer to obtain an ESCAP resin.

[0009] Preferably, the catalyst is copper and cuprous bromide.

[0010] A molar ratio of copper to cuprous bromide that is too high can accelerate the reaction, produce uneven molecular segments, and broaden the PDI. A molar ratio that is too low can prolong the reaction time and result in a lower molecular weight within the same reaction time. More preferably, the molar ratio of copper to cuprous bromide is (1-2):1. For example, it can be (1-1.5):1 or (1.5-2):1, and more preferably (1-1.5:1).

[0011] Preferably, the complex is bipyridine.

[0012] A too low molar ratio of the complexing agent to the catalyst will affect the conversion between copper and cuprous bromide, thus affecting the catalytic effect. More preferably, the molar amount of the complexing agent is 1 to 3 times the total molar amount of the catalyst. For example, it can be 1 to 1.5 times, 1.5 to 2.0 times, 2.0 to 2.5 times, 2.5 to 3.0 times, and preferably 1.5 to 2.0 times.

[0013] Preferably, the initiator is α,α'-dibromo-p-xylene and / or 1-phenylethyl bromide.

[0014] Preferably, the molar amount of the initiator is 0.1-0.3% of the molar amount of the tert-butyl acrylate, such as 0.1-0.15%, 0.15-0.2%, 0.2-0.25%, 0.25-0.3%, and more preferably 0.25-0.3%.

[0015] Preferably, the molar ratio of the 4-acetoxystyrene to the tert-butyl acrylate is (1-3):1, such as (1-1.5):1, (1.5-2):1, (2-2.5):1, (2.5-3):1, and more preferably (1.5-2):1.

[0016] Preferably, the raw materials for the ammonolysis reaction include aqueous ammonia and methanol.

[0017] More preferably, the mass of the ammonia water is 1 to 3 times the mass of the prepolymer, such as 1 to 1.5 times, 1.5 to 2 times, 2 to 2.5 times, 2.5 to 3 times, and preferably 1.5 to 2 times.

[0018] More preferably, the concentration of the ammonia water is 25-28 wt%.

[0019] More preferably, the mass of the methanol is 2 to 5 times the mass of the prepolymer, such as 2 to 2.5 times, 2.5 to 3 times, 3 to 3.5 times, 3.5 to 4 times, 4 to 4.5 times, 4.5 to 5 times, and preferably 2.5 to 3 times.

[0020] Preferably, in the ATRP reaction, the reaction atmosphere is an inert atmosphere, more preferably a nitrogen atmosphere.

[0021] Preferably, during the ATRP reaction, the reaction temperature is 80-100°C, such as 80°C, 90°C, or 100°C, and more preferably 90°C.

[0022] Preferably, the ATRP reaction has a reaction time of 1 to 3 hours, such as 1 hour, 2 hours, or 3 hours, and more preferably 3 hours.

[0023] Preferably, the ATRP reaction further comprises a post-treatment step, wherein the post-treatment comprises filtration, precipitation, and drying. More preferably, the filtration step comprises adding the reaction solution to ethyl acetate and performing solid-liquid separation using diatomaceous earth to obtain a filtrate, and the filtrate is repeatedly filtered until a transparent reddish-brown filtrate is obtained. More preferably, the precipitation step comprises adding 10-15 volumes of n-hexane to the filtrate to precipitate the filtrate. More preferably, the filtration step comprises obtaining a precipitate through solid-liquid separation. More preferably, the drying step comprises drying the precipitate in a vacuum oven at 60-80°C for 24-48 hours.

[0024] Preferably, during the ammonolysis reaction, the reaction atmosphere is an inert atmosphere, more preferably a nitrogen atmosphere.

[0025] Preferably, the reaction temperature of the ammonolysis reaction is 75-85°C, such as 75°C, 80°C, or 85°C, and more preferably 80°C.

[0026] Preferably, the reaction time of the ammonolysis reaction is 16 to 20 hours, more preferably 16 hours.

[0027] Preferably, the ammonolysis reaction further comprises a post-treatment step, wherein the post-treatment comprises precipitation, filtration, and drying. More preferably, the precipitation step comprises adding the reaction solution to 10-15 volumes of an aqueous acetic acid solution (with an acetic acid mass fraction of 3.6-4.0%). More preferably, the filtration step comprises obtaining a precipitate by solid-liquid separation. More preferably, the drying step comprises drying the precipitate in a vacuum oven at 60-80°C for 24-48 hours.

[0028] A second object of the present invention is to disclose the ESCAP resin described above.

[0029] Preferably, the molecular weight distribution index of the ESCAP resin is 1.2 to 1.5, more preferably 1.3 to 1.4.

[0030] Preferably, the weight average molecular weight of the ESCAP resin is 20,000 to 25,000.

[0031] A third object of the present invention is to disclose a method for purifying the ESCAP resin described above, wherein the purification method comprises purifying the ESCAP resin with IRC747 ion exchange resin and / or A15 ion exchange resin.

[0032] Preferably, the ESCAP resin is purified by the IRC747 ion exchange resin and the A15 ion exchange resin connected in series.

[0033] Preferably, before purification, the ESCAP resin is dissolved in a solvent to form an ESCAP resin solution having a solid content of 15-20 wt%. If the solid content is too high, the molecular chains of the ESCAP resin will not stretch, and metal ions will be trapped in the molecular chains and difficult to remove, resulting in ineffective purification of the ESCAP resin to the target value. If the solid content is too low, purification efficiency will be low and post-processing costs will increase.

[0034] Preferably, during purification, the flow rate is 1 to 3 bv / h, such as 1 to 2 bv / h, 2 to 3 bv / h, and more preferably 2 bv / h.

[0035] More preferably, the solvent is methanol.

[0036] Preferably, the purification process further includes post-processing, wherein the post-processing comprises precipitation, filtration, and drying. More preferably, the precipitation is performed by adding the purified solution to ultrapure water. Even more preferably, the filtration is performed by solid-liquid separation to obtain a precipitate. Even more preferably, the drying is performed by drying the precipitate in a vacuum oven at 60-80°C for 24-48 hours.

[0037] Preferably, ion exchange resins IRC747 and A15 are pretreated before purification, and the pretreatment method is as follows:

[0038] 1) Use 4-5% hydrochloric acid solution to wash the ion exchange resin. The volume of the hydrochloric acid solution is 4-5 times the volume of the ion exchange resin. The flow rate is 2-3 bv / h. After washing, soak the ion exchange resin in the hydrochloric acid solution for 12-14 hours.

[0039] 2) After soaking, wash the ion exchange resin with ultrapure water until the pH value of the effluent is 7.00±0.10.

[0040] 3) The ion exchange resin is further flushed with electronic grade methanol, the volume of which is 3-4 times the volume of the ion exchange resin, and the flow rate is 2-3 bv / h.

[0041] A fourth object of the present invention is to disclose a pure ESCAP resin obtained by treating the ESCAP resin with the purification method described above.

[0042] Preferably, the total metal ion content of the pure ESCAP resin is less than 100 ppb, and the content of a single metal ion is less than 10 ppb.

[0043] More preferably, the total metal ion content of the pure ESCAP resin is less than 30 ppb, and the content of a single metal ion is less than 6 ppb.

[0044] More preferably, the total metal ion content of the pure ESCAP resin is less than 15 ppb, and the content of a single metal ion is less than 6 ppb.

[0045] A fifth object of the present invention is to disclose the use of the pure ESCAP resin as described above as a photoresist resin.

[0046] Preferably, the photoresist resin is a 245nm photoresist resin.

[0047] The present invention discloses an ESCAP resin and a preparation method, a purification method and use thereof. The ESCAP resin prepared by the ATRP reaction of the present invention has a low molecular weight distribution index, and after purification, the total metal ion content of the ESCAP resin can be reduced to below 100 ppb, and the content of each metal ion can be reduced to below 10 ppb. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Shown are infrared spectra of the prepolymer and ESCAP resin prepared in Example 1 of the present invention.

[0049] Figure 2 Shown are the H-NMR spectra of the prepolymer and ESCAP resin prepared in Example 1 of the present invention.

[0050] Figure 3 Shown is the NMR carbon spectrum of the ESCAP resin prepared in Example 1 of the present invention.

[0051] Figure 4 Shown are TGA curves of the prepolymer and ESCAP resin prepared in Example 1.

[0052] Figure 5 Shown are the DSC curves of the prepolymer prepared in Example 1 and the ESCAP resin. DETAILED DESCRIPTION

[0053] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0054] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0055] Furthermore, it should be understood that the one or more method steps mentioned in the present invention do not exclude the presence of other method steps before or after the combination step, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified. It should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the presence of other devices / apparatuses before or after the combination device / apparatus, or the insertion of other devices / apparatuses between two explicitly mentioned devices / apparatuses, unless otherwise specified. Furthermore, unless otherwise specified, the numbering of each method step is merely a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be considered within the scope of the present invention.

[0056] Ion exchange resins IRC747 and A15 were pretreated before purification. The pretreatment method was as follows:

[0057] (1) Use 4% hydrochloric acid solution to wash the ion exchange resin. The volume of the hydrochloric acid solution is 4-5 times the volume of the ion exchange resin, and the flow rate is 2 bv / h. After washing, soak the ion exchange resin in the hydrochloric acid solution for 12-14 hours.

[0058] (2) After soaking, the ion exchange resin was washed with ultrapure water until the pH value of the effluent was 7.00 ± 0.10.

[0059] (3) The ion exchange resin is further flushed with electronic grade methanol, the volume of which is 3-4 times the volume of the ion exchange resin, and the flow rate is 2 bv / h.

[0060] The reagents used in the following examples are as follows:

[0061] 4-Acetoxystyrene (4-AST) (electronic grade, purity ≥99.0%, purchased from Shanghai Aiqiao Chemical Reagent Co., Ltd.) was purified by basic alumina column (Adamas, purity ≥99.99%) to remove inhibitors before use;

[0062] Tert-butyl acrylate (TBA) (electronic grade, purity ≥99.0%, purchased from Shanghai Aiqiao Chemical Reagent Co., Ltd.) was purified by basic alumina column (Adamas, purity ≥99.99%) to remove inhibitors before use;

[0063] Cuprous bromide (Adamas, purity ≥99.0%) was pretreated with acetic acid (Greagent, purity ≥99.5%) and methanol for 24 h and placed under nitrogen for several hours before use;

[0064] Methanol (purchased from Jingrui Electronic Materials Co., Ltd., electronic grade, purity ≥99.7%);

[0065] Ultrapure water (ultrapure water device homemade);

[0066] Copper powder (Leyan, particle size 60-100 nm);

[0067] α,α'-dibromo-p-xylene (Adamas, purity ≥97%);

[0068] Bipyridine (bpy) (Adamas, purity ≥99.0%);

[0069] Ethyl acetate (Greagent, purity ≥99.5%);

[0070] n-Hexane (Greagent, purity ≥97.0%);

[0071] Ammonia (Greagent, concentration 25-28%);

[0072] Hydrochloric acid (Adamas, single metal <1 ppb).

[0073] Example 1

[0074] This embodiment provides a specific method for preparing ESCAP resin, and the specific steps are as follows:

[0075] (1) Preparation of prepolymer poly(AOST-co-TBA)

[0076] Treated 4-AST (0.3 mol) and TBA (0.2 mol) were added to an absolutely dry Schlenk flask, followed by bpy (4.5 mmol) and stirring for 3-5 minutes. After thoroughly mixing the monomers and bpy, CuBr (1.5 mmol), Cu (1.5 mmol), and α,α'-dibromo-p-xylene (0.75 mmol) were added in sequence. The Schlenk flask was sealed with a rubber septum and subjected to three freeze-thaw cycles under nitrogen before being backfilled with nitrogen. The flask was then placed in a 90°C oil bath and stirred for 3 hours.

[0077] After the reaction is complete, the reactants are dissolved in ethyl acetate and filtered through diatomaceous earth to remove insoluble matter. This filtration process is repeated 2-3 times until a transparent reddish-brown solution is obtained. The resulting solution is slowly added to 10 volumes of n-hexane for reprecipitation. The precipitate is filtered to obtain a precipitate, which is then placed in a clean vacuum oven and dried at 60°C for 24 hours to obtain a white powdery prepolymer.

[0078] (2) Preparation of ESCAP resin poly(HOST-co-TBA)

[0079] Place the prepolymer in a clean two-necked flask, add methanol and aqueous ammonia, and reflux at 80°C for 16 hours in a nitrogen atmosphere. The mass ratio of methanol to prepolymer is 2.5:1, and the mass ratio of aqueous ammonia to prepolymer is 1.5:1.

[0080] The obtained reaction solution was slowly added to 10 volumes of acetic acid aqueous solution (3.6%) for reprecipitation, and the precipitate was obtained by filtration. The precipitate was placed in a clean vacuum oven and dried at 60° C. for 24 h to obtain a white powdery ESCAP resin.

[0081] The prepolymer and ESCAP resin prepared in Example 1 were subjected to the following structural characterization:

[0082] (1) Infrared analysis was performed using a Thermo Scientific spectrometer. The infrared spectra are shown in Figure 2. Figure 1 .like Figure 1 As shown in the figure, the infrared spectrum of prepolymer poly(AOST-co-TBA) is 3340 cm-1 compared with ESCAP resin poly(HOST-co-TBA). -1 A broad absorption peak appears near 1760 cm -1 The nearby -C=O characteristic absorption peak disappears, indicating that the acetoxy group is completely aminolyzed into a hydroxyl group.

[0083] (2) H NMR analysis was performed using a Bruker Acance Neo 400 MHz nuclear magnetic resonance spectrometer, using dimethyl sulfoxide (DMSO-d6) as solvent and tetramethylsilane as internal reference. The H NMR spectrum is shown in Figure 2Compared with the ESCAP resin poly(HOST-co-TBA), the hydrogen spectrum of the prepolymer poly(AOST-co-TBA) shows a peak at δ=8.5-9.5ppm, corresponding to the hydrogen on the phenolic hydroxyl group, and the hydrogen spectrum of poly(AOST-co-TBA) shows a peak at δ=2.22ppm, which corresponds to the methyl on the acetoxy group. This peak disappears in the hydrogen spectrum of poly(HOST-co-TBA), indicating that poly(AOST-co-TBA) is completely aminolyzed.

[0084] The ESCAP resin prepared in Example 1 was subjected to the following structural characterization:

[0085] The ESCAP resin prepared in Example 1 was analyzed by nuclear magnetic resonance carbon spectrum using a Bruker AcanceNeo 400 MHz NMR spectrometer with dimethyl sulfoxide (DMSO-d6) as solvent and tetramethylsilane as internal reference. Figure 3 shown. Figure 3 The characteristic peak at chemical shift δ=27-28.5 ppm corresponds to the carbon on the tert-butoxy group, and the characteristic peaks at δ=114-116 ppm, δ=127-129.5 ppm and δ=155-156.5 ppm correspond to the carbon on the benzene ring of p-hydroxystyrene.

[0086] The following performance tests were performed on the prepolymer and ESCAP resin prepared in Example 1:

[0087] (1) Thermogravimetric analysis (TGA) was performed using a TGA 550 thermogravimetric analyzer. The sample was heated from 50°C to 800°C at a rate of 10°C / min under a nitrogen atmosphere. The TGA curve is shown in Figure 2. Figure 4 shown.

[0088] From the TGA curves, it can be seen that the temperature (T d ) were 247.67℃ and 210.76℃, respectively, indicating good thermal stability. The T g (115℃) than its T d (210℃) is about 95℃ lower, which is beneficial for regulating the temperature during use of photoresist resin.

[0089] (2) Differential scanning calorimetry (DSC) was used to determine the glass transition temperature (T) by heating the sample from 50°C to 180°C at a rate of 10°C / min using a DSC 25 differential scanner. g), DSC curve is as follows Figure 5 shown.

[0090] From the DSC curve, it can be seen that the T g At 101°C, the T of ESCAP resin poly(HOST-co-TBA) g The temperature is 115℃, which meets the high thermal performance requirements of 248nm photoresist resin.

[0091] Examples 2-3

[0092] This example provides a specific method for preparing ESCAP resin, which is basically the same as the preparation method in Example 1, except that the reaction times are 1 h and 2 h, respectively.

[0093] Example 4

[0094] This embodiment provides a specific method for purifying ESCAP resin, and the specific method is as follows:

[0095] The ESCAP resin prepared in Example 1 was dissolved in methanol as a sample to be treated. The solid content of the sample to be treated was 20%. The sample to be treated was passed through columns filled with ion exchange resins A15 and IRC747 in sequence at a flow rate of 2 bv / h to obtain an effluent. The effluent was added to ultrapure water for reprecipitation, and the precipitate was obtained by filtration. The precipitate was placed in a clean vacuum oven and dried at 60°C for 24 h to obtain pure ESCAP resin with a yield of 79.3%.

[0096] Example 5

[0097] This example provides a specific ESCAP resin purification method, which is basically the same as the purification method in Example 4, except that the sample to be processed is sequentially passed through columns filled with ion exchange resins IRC747 and A15 to obtain an effluent with a yield of 76.8%.

[0098] Examples 6-7

[0099] This example provides a specific ESCAP resin purification method, which is basically the same as the purification method in Example 5, except that the flow rates of the sample to be processed are 1 bv / h and 3 bv / h respectively.

[0100] Comparative Example 1

[0101] This comparative example is a comparative example of Example 4, except that the sample to be treated is passed through a column filled with ion exchange resin A15 to obtain an effluent.

[0102] Comparative Example 2

[0103] This comparative example is a comparative example of Example 4, except that the sample to be treated is passed through a column filled with ion exchange resin IRC747 to obtain an effluent.

[0104] Comparative Example 3

[0105] This comparative example is a comparative example of Example 4, except that the sample to be treated is sequentially passed through columns filled with ion exchange resins Amberlite IRC76CRF and Amberlyst 15wet to obtain an effluent.

[0106] Comparative Example 4

[0107] This comparative example is a comparative example of Example 4, except that the sample to be treated is sequentially passed through columns filled with ion exchange resins Amberlite HPR650H and Amberlyst 15wet to obtain an effluent.

[0108] The molecular weight, molecular weight distribution index, monomer conversion rate and prepolymer composition of the ESCAP resins prepared in Examples 1 to 3 were measured. The test results are shown in Table 1. The test method is as follows:

[0109] The molecular weight and molecular weight distribution index were determined by gel permeation chromatography. The analysis conditions were:

[0110] Instrument: Gel permeation chromatograph (model Waters 2695);

[0111] Analytical conditions: Using a differential refractive index detector (model Waters 2414), a Waters HR1 / HR3 / HR4 connection in series, the relative molecular weight separation range of the HR1, HR3, and HR4 columns was 1140 to 328,000, THF was used as the mobile phase, the flow rate was 1 ml / min, and the measurement was performed at 35°C. Molecular weights were calibrated with polystyrene. Table 1

[0112]

[0113]

[0114] The metal ion content in the ESCAP resin prepared in Example 1, the pure ESCAP resins prepared in Examples 4 to 5, and Comparative Examples 1 to 4 was determined by ICP-MS. The test results are shown in Table 2.

[0115] Instrument model: Nexion 5000G;

[0116] The analysis conditions were as follows: ICP power of 1600 W, cooling gas flow of 15 L / min, auxiliary gas flow of 0.03 L / min, argon gas flow rate of 0.88 ml / min, sample lift volume of 1 ml / min, and nebulizer temperature of -5°C.

[0117] Table 2 Metal content / ppb

[0118]

[0119]

[0120] As can be seen from Table 2, only by using ion exchange resins A15 and IRC747 in series can the total metal ion content after purification be less than 100 ppb and the content of a single metal ion be less than 10 ppb. If ion exchange resins A15 or IRC747 are used alone, the above effects cannot be achieved. The above effects cannot be achieved by using ion exchange resins Amberlite IRC76CRF and Amberlyst15wet in series, or Amberlite HPR650H and Amberlyst 15wet in series.

[0121] The metal ion content in the ESCAP resins prepared in Examples 5 to 7 was determined by ICP-MS, and the test results are shown in Table 4. The ICP-MS test conditions were the same as above.

[0122] Table 3 Metal ion content / ppb

[0123]

[0124]

[0125] As can be seen from Table 3, the total metal ion concentrations at flow rates of 1 bv / h, 2 bv / h, and 3 bv / h are 34.35 ppb, 12.88 ppb, and 55.5 ppb, respectively. Too high or too low a flow rate will affect the efficiency of ion exchange.

[0126] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for preparing an ESCAP resin, characterized in that: The preparation method comprises the following steps: subjecting 4-acetoxystyrene and tert-butyl acrylate to an ATRP reaction under the action of a catalyst, a complexing agent and an initiator to obtain a prepolymer; and aminolyzing the prepolymer to obtain an ESCAP resin.

2. The preparation method according to claim 1, characterized in that The catalyst is copper and cuprous bromide; and / or, the complex is bipyridine; and / or, the initiator is α,α'-dibromo-p-xylene and / or 1-phenylethyl bromide; and / or, the molar ratio of the 4-acetoxystyrene to the tert-butyl acrylate is (1-3):1; and / or, the total molar amount of the catalyst is 0.5 to 1.5% of the molar amount of the 4-acetoxystyrene; and / or, the molar amount of the complexing agent is 1 to 3 times the total molar amount of the catalyst; and / or, the molar amount of the initiator is 0.1 to 0.3% of the molar amount of the tert-butyl acrylate; and / or, the raw materials for the ammonolysis reaction include aqueous ammonia and methanol; And / or, in the ATRP reaction, the reaction atmosphere is an inert atmosphere; and / or, during the ATRP reaction, the reaction temperature is 80-100° C.; And / or, during the ATRP reaction, the reaction time is 1 to 3 hours; And / or, the ATRP reaction further comprises a post-processing step, wherein the post-processing step comprises filtration, precipitation, and drying; and / or, in the ammonolysis reaction, the reaction atmosphere is an inert atmosphere; and / or, the reaction temperature of the ammonolysis reaction is 75-85° C.; And / or, the ammonolysis reaction further comprises a post-treatment step, wherein the post-treatment step comprises precipitation, filtration, and drying.

3. The preparation method according to claim 2, characterized in that The molar ratio of the copper to the cuprous bromide is (1-2):1; and / or, the mass of the ammonia water is 1 to 3 times the mass of the prepolymer; And / or, the mass of the methanol is 2 to 5 times the mass of the prepolymer.

4. The ESCAP resin obtained by the preparation method according to any one of claims 1 to 3.

5. The ESCAP resin according to claim 4, characterized in that The molecular weight distribution index of the ESCAP resin is 1.2-1.5; the weight average molecular weight of the ESCAP resin is 20,000-25,000.

6. A method for purifying the ESCAP resin according to any one of claims 4 to 5, characterized in that: The ESCAP resin is purified by IRC747 ion exchange resin and / or A15 ion exchange resin.

7. The purification method according to claim 6, characterized in that Includes one or more of the following features: a) purifying the ESCAP resin via the IRC747 ion exchange resin and the A15 ion exchange resin connected in series; b) before purification, dissolving the ESCAP resin in a solvent to form an ESCAP resin solution, wherein the solid content of the ESCAP resin solution is 15 to 20 wt %; c) During purification, the flow rate is 1 to 3 bv / h; d) the purification process further comprises post-treatment, wherein the post-treatment comprises precipitation, filtration and drying; e) Ion exchange resins IRC747 and A15 were pretreated before purification. The pretreatment method was as follows: 1) Wash the ion exchange resin with a 4-5% hydrochloric acid solution, the volume of the hydrochloric acid solution being 4-5 times the volume of the ion exchange resin, at a flow rate of 2-3 bv / h. After washing, soak the ion exchange resin in the hydrochloric acid solution for 12-14 hours; 2) After soaking, wash the ion exchange resin with ultrapure water until the pH value of the effluent is 7.00 ± 0.10; 3) The ion exchange resin is further flushed with electronic grade methanol, the volume of which is 3-4 times the volume of the ion exchange resin, and the flow rate is 2-3 bv / h.

8. A pure ESCAP resin obtained by the purification method according to any one of claims 6 to 7.

9. The pure ESCAP resin according to claim 8, characterized in that: The pure ESCAP resin has a total metal ion content of less than 100 ppb, and a single metal ion content of less than 10 ppb.

10. Use of the pure ESCAP resin according to any one of claims 8 to 9 as a photoresist resin.

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