Purification method and purification system for photoresist resin

Abstract

The invention provides a purification method and a purification system for photoresist resin. The purification method comprises the following steps: enabling the photoresist resin to be treated to sequentially pass through a first purification unit and a second purification unit; wherein the first purification unit comprises adsorption resin and / or a molecular sieve; the second purification unit comprises mixed resin; the mixed resin is formed by mixing cation exchange resin and anion exchange resin. According to the purification method, metal impurities and moisture in the photoresist resin can be well removed, and the photoresist resin solution or photoresist resin powder can be obtained; in addition, the purification method is simple to operate, the sources of purification raw materials are wide, and the purification efficiency is high.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor integrated circuits, in particular to the technical field of resin purification, and specifically relates to a purification method and a purification system for photoresist resin. Background Art

[0002] Photoresist resin is an important component of photoresist. In order to meet the performance requirements of photoresist, the metal impurities and moisture in the photoresist resin must be processed to a level of a relatively low content. However, unlike single-molecule materials such as photosensitizers and solvents, photoresist resin is composed of molecular chains of different chain lengths, and the molecular chain lengths are normally distributed. This characteristic greatly increases the difficulty of purifying the photoresist resin. In industry, the purification method of traditional KrF photoresist resin has a membrane filter method and an ion exchange resin purification method, but the photoresist resin purified by the traditional method still has the problems of high metal impurity content, high residual moisture content, and low detection film retention rate. Conventional purification methods can no longer meet the precision requirements of metal impurities and moisture removal. Therefore, it is very necessary to develop a method for removing metal impurities and moisture with good performance and high film retention rate of purified photoresist resin. Summary of the invention

[0003] In order to solve the problem that metal impurities and moisture in the existing photoresist resin are difficult to remove, the present invention provides a purification method and a purification system for photoresist resin. The purification method can effectively remove metal impurities and moisture in the photoresist resin and obtain photoresist resin glue or photoresist resin powder; in addition, the purification method is simple to operate, has a wide source of purification raw materials, and has high purification efficiency.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A method for purifying a photoresist resin, the method comprising:

[0006] The photoresist resin to be treated is passed through a first purification unit and a second purification unit in sequence; wherein the first purification unit includes an adsorption resin and / or a molecular sieve; the second purification unit includes a mixed resin; the mixed resin is a resin formed by mixing a cation exchange resin and an anion exchange resin.

[0007] According to an embodiment of the present invention, the photoresist resin is KrF photoresist resin.

[0008] According to an embodiment of the present invention, the photoresist resin to be treated contains metal impurities. Specifically, the metal impurities include but are not limited to at least one of Li, Na, Mg, Al, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Pd, Ag, Cd, Sn, Au and Pb.

[0009] According to an embodiment of the present invention, the total content of metal impurities in the photoresist resin to be treated is not less than 10 ppm, such as not less than 50 ppm, and for example not less than 100 ppm.

[0010] According to an embodiment of the present invention, the photoresist resin to be treated contains moisture.

[0011] According to an embodiment of the present invention, the moisture content in the to-be-treated photoresist resin is not less than 2%, such as not less than 5%, and for example not less than 8%.

[0012] According to an embodiment of the present invention, the system in which the photoresist resin to be treated exists is a system in which an organic solvent exists, that is, the photoresist resin to be treated exists in a form of being mixed with an organic solvent. For example, the organic solvent is at least one of an ester organic solvent, an alcohol organic solvent and an ether organic solvent.

[0013] According to an embodiment of the present invention, the ester organic solvent, alcohol organic solvent and ether organic solvent are commonly used in the field of photoresist resin, especially in the field of KrF photoresist resin.

[0014] Exemplarily, the ester organic solvent is propylene glycol methyl ether acetate (PGMEA); and the alcohol organic solvent is methanol.

[0015] According to an embodiment of the present invention, the first purification unit includes an adsorption resin, or the first purification unit includes a molecular sieve, or the first purification unit includes a combination of an adsorption resin and a molecular sieve.

[0016] According to an embodiment of the present invention, if the first purification unit includes a combination of an adsorption resin and a molecular sieve, the mass ratio of the adsorption resin and the molecular sieve is not particularly limited, for example, it is 1:9-9:1, for example, 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2 or 9:1.

[0017] According to an embodiment of the present invention, the adsorption resin is selected from at least one of a mesoporous adsorption resin, a microporous adsorption resin and a macroporous adsorption resin.

[0018] Preferably, the adsorption resin is selected from a combination of a mesoporous adsorption resin and a microporous adsorption resin, and the mass ratio of the mesoporous adsorption resin to the microporous adsorption resin is 1:1-5; or the adsorption resin is selected from a combination of a macroporous adsorption resin and a mesoporous adsorption resin, and the mass ratio of the macroporous adsorption resin to the mesoporous adsorption resin is 1:1-5; or the adsorption resin is selected from a combination of a macroporous adsorption resin and a microporous adsorption resin, and the mass ratio of the macroporous adsorption resin to the microporous adsorption resin is 1:1-5; or the adsorption resin is selected from a combination of a macroporous adsorption resin, a mesoporous adsorption resin and a microporous adsorption resin, and the mass ratio of the macroporous adsorption resin, the mesoporous adsorption resin and the microporous adsorption resin is 1:1-5:1-5.

[0019] According to an embodiment of the present invention, the mesoporous adsorption resin refers to an adsorption resin with a pore size of 2-50 nm; the microporous adsorption resin refers to an adsorption resin with a pore size less than 2 nm; and the macroporous adsorption resin refers to an adsorption resin with a pore size greater than 50 nm.

[0020] According to an embodiment of the present invention, the adsorption resin is a spherical, non-polar polymer adsorbent. Exemplarily, the adsorption resin is a cross-linked styrene-divinylbenzene copolymer.

[0021] According to an embodiment of the present invention, the molecular sieve is a microporous molecular sieve, and the pore size of the microporous molecular sieve is

[0022] According to an embodiment of the present invention, the adsorption resin and / or molecular sieve is loaded into a chromatography column to form a first purification unit for photoresist resin. Preferably, the macroporous adsorption resin, mesoporous adsorption resin and microporous adsorption resin are sequentially loaded into a chromatography column to form a first purification unit for photoresist resin, wherein the macroporous adsorption resin is located at the upper part of the chromatography column, the mesoporous adsorption resin is located at the middle part of the chromatography column, and the microporous adsorption resin is located at the lower part of the chromatography column.

[0023] According to an embodiment of the present invention, the first purification unit includes at least one chromatography column (such as a PFA column), and the chromatography column is filled with an adsorption resin and / or a molecular sieve. The number of chromatography columns in the first purification unit can be reasonably adjusted according to the amount of the photoresist resin to be treated to ensure efficient removal of water in the photoresist resin.

[0024] According to an embodiment of the present invention, the inner diameter of the chromatography column is not particularly defined, for example, 5 to 50 cm, such as 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, 45 cm or 50 cm.

[0025] According to an embodiment of the present invention, at room temperature and pressure, the photoresist resin to be treated passes through the first purification unit, ie, through a chromatography column filled with adsorption resin and / or molecular sieve, at a flow rate of 2 to 50 ml / min.

[0026] According to an embodiment of the present invention, the first purification unit is used to remove moisture from the photoresist resin to be processed.

[0027] According to an embodiment of the present invention, the cation exchange resin is, for example, a strong acid cation exchange resin. Specifically, the cation exchange resin is selected from styrene sulfonic acid resin; more specifically, the comonomers of the cation exchange resin are styrene and divinylbenzene, the matrix is ​​gel, and the functional group is a sulfonic acid group; illustratively, the cation exchange resin is a strong acid 1200Na cation exchange resin (the copolymer of the resin is a styrene-divinylbenzene copolymer, the matrix is ​​gel, and the functional group is a sulfonic acid group).

[0028] According to an embodiment of the present invention, the anion exchange resin is, for example, a strong base anion exchange resin. Specifically, the anion exchange resin is selected from a styrene-based aminated resin; more specifically, the comonomers of the anion exchange resin are styrene and divinylbenzene, and the functional group is -N(CH3)3-; illustratively, the anion exchange resin is a strong base 4200Cl anion exchange resin (the copolymer of the resin is a styrene-divinylbenzene copolymer, and the functional group is -N(CH3)3-).

[0029] According to an embodiment of the present invention, the mass ratio of the cation exchange resin to the anion exchange resin in the mixed resin is 1:1.5-4, for example, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5 or 1:4. The adsorption capacity of the mixed resin for metal impurities can be adjusted by adjusting the mass ratio of the cation exchange resin to the anion exchange resin. When the mass ratio of the cation exchange resin to the anion exchange resin is 1:1.5-4, the adsorption of metal impurities in the photoresist resin can be well achieved.

[0030] According to an embodiment of the present invention, the mixed resin is prepared by the following method:

[0031] The mixed resin is prepared by mixing Lewis acid, cation exchange resin and anion exchange resin, and heating and curing.

[0032] Wherein, the Lewis acid is selected from aluminum chloride and / or ferric chloride.

[0033] Wherein, the mass ratio of the cation exchange resin to the anion exchange resin is 1:1.5-4, for example, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5 or 1:4.

[0034] The mass of the Lewis acid accounts for 1-5wt% of the total mass of the cation exchange resin and the anion exchange resin, such as 1wt%, 2wt%, 3wt%, 4wt% or 5wt%.

[0035] The heating curing temperature is 100-150°C, for example, 100°C, 120°C, 130°C, 140°C or 150°C; the heating curing time is 2-8 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours or 8 hours.

[0036] According to the embodiment of the present invention, the mixed resin after being heated and cured can give full play to its adsorption capacity for metal impurities in the photoresist resin, thereby improving the purification efficiency of the metal impurities in the photoresist resin.

[0037] According to an embodiment of the present invention, the mixed resin is pre-exchanged with an alcohol organic solvent (such as methanol, ethanol, etc.; preferably methanol) before use, with the aim of further removing moisture in the mixed resin and that which may be produced during the ion exchange reaction between the mixed resin and the photoresist resin, thereby improving the purification effect of the photoresist resin.

[0038] According to an embodiment of the present invention, the mixed resin is loaded into a chromatography column to form a second photoresist resin purification unit.

[0039] According to an embodiment of the present invention, the second purification unit includes at least four chromatography columns. The number of chromatography columns in the second purification unit can be reasonably adjusted according to the amount of photoresist resin to be processed to ensure efficient removal of metal impurities in the photoresist resin.

[0040] Exemplarily, the second purification unit is formed by four chromatography columns (such as PFA columns) connected in series via pipelines (such as PFA hoses), and the chromatography columns are filled with mixed resins.

[0041] The inner diameter of the chromatography column is not particularly defined, for example, 5 to 50 cm, such as 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, 45 cm or 50 cm.

[0042] According to an embodiment of the present invention, at room temperature and pressure, the photoresist resin to be treated passes through the second purification unit, ie, through the chromatography column filled with the mixed resin, at a flow rate of 2 to 50 ml / min.

[0043] According to an embodiment of the present invention, the second purification unit is used to remove metal impurities in the photoresist resin.

[0044] According to the embodiment of the present invention, the purification method can process metal impurities and moisture in the photoresist resin, has good purification effect, and can obtain photoresist resin powder or clear and transparent photoresist resin glue solution as needed.

[0045] Specifically, an adsorption resin and / or a molecular sieve are selected to absorb the moisture in the photoresist resin; the photoresist resin containing metal impurities after the moisture is removed is passed through a mixed resin; the mixed resin is obtained by mixing cation exchange resin and anion exchange resin in different proportions and curing by heating, and the mixed resin is pre-exchanged with an alcohol organic solvent before use; when the photoresist resin is contacted with such a mixed resin, the metal impurities in the photoresist resin can replace hydroxide ions after the anion exchange resin in the mixed resin contacts the photoresist resin, and the metal impurities in the photoresist resin can replace hydrogen ions after the cation exchange resin contacts the photoresist resin; the replaced hydrogen ions and hydroxide ions will undergo a neutralization reaction, and the removal of metal impurities in the photoresist resin is well achieved in this way. At the same time, since the mixed resin is treated with an alcohol organic solvent, no new moisture will be introduced. At the same time, since the metal impurities and water in the photoresist resin have a small volume, they can also be freely adsorbed into the microscopic pores of the mixed resin, thereby achieving the purpose of further removing metal impurities and water in the photoresist resin. More importantly, since the cation exchange reaction and the anion exchange reaction can occur simultaneously, the hydroxide ions exchanged by the anion exchange resin and the hydrogen ions exchanged by the cation exchange resin will immediately undergo a neutralization reaction, and hydrogen ions or hydroxide ions will not accumulate, thus avoiding the deprotection reaction caused by residual acid. The photoresist resin treated with the mixed resin can still retain a high film retention rate after development.

[0046] According to an embodiment of the present invention, the purification method further comprises filtering, that is, filtering the photoresist resin after being processed by the second purification unit. Specifically, the photoresist resin after being processed by the second purification unit is sent to a filter for filtering.

[0047] According to an embodiment of the present invention, the purpose of the filtration is to remove particles in the photoresist resin system. The particles are, for example, particles produced by introducing solid components such as adsorption resin, molecular sieve or mixed resin into the photoresist resin system after being processed by the first purification unit and the second purification unit, and may also be particles existing in the photoresist resin solution.

[0048] According to an embodiment of the present invention, the purification method further comprises: using a precipitant n-heptane to precipitate the purified photoresist resin, then collecting the solid photoresist resin after filtration, and then removing the precipitant n-heptane through vacuum drying to obtain photoresist resin powder.

[0049] According to an embodiment of the present invention, the content of total metal impurities in the photoresist resin (specifically, photoresist resin powder) is less than or equal to 1000ppb, such as less than or equal to 800ppb, such as less than or equal to 600ppb, such as less than or equal to 500ppb, such as less than or equal to 300ppb, such as less than or equal to 100ppb. The moisture content in the photoresist resin (specifically, photoresist resin powder) is less than or equal to 0.4%, such as less than or equal to 0.3%, such as less than or equal to 0.2%, such as less than or equal to 0.1%, such as less than or equal to 0.08%.

[0050] According to an embodiment of the present invention, the film retention rate of the photoresist resin glue is not less than 70%, preferably not less than 80%, preferably not less than 90%, preferably not less than 95%. The photoresist resin glue is a photoresist resin glue containing 30% PGMEA formed by dissolving purified photoresist resin powder in a PGMEA organic solvent, and the film retention rate of the photoresist resin glue containing 30% PGMEA after pre-baking, developing and post-baking is not less than 70%, preferably not less than 80%, preferably not less than 90%, preferably not less than 95%.

[0051] The present invention also provides a purification system for photoresist resin, the purification system comprising a first purification unit for photoresist resin, a multi-channel precision peristaltic pump, a second purification unit for photoresist resin and a filter;

[0052] The first photoresist resin purification unit, the second photoresist resin purification unit and the filter are connected in sequence;

[0053] The first photoresist resin purification unit includes adsorption resin and / or molecular sieve; the second photoresist resin purification unit includes mixed resin; the mixed resin is a resin formed by mixing a cation exchange resin and an anion exchange resin.

[0054] According to an embodiment of the present invention, the first purification unit in the purification system is selected from the first purification unit in the above method.

[0055] According to an embodiment of the present invention, the second purification unit in the purification system is selected from the second purification unit in the above method.

[0056] Beneficial effects:

[0057] The purification system and purification method of the present invention can not only effectively reduce the content of metal impurities in the photoresist resin, but also effectively reduce the moisture in the photoresist resin, and can obtain photoresist resin powder or clear and transparent photoresist resin glue liquid as needed. The purification system and purification method have the advantages of high automation, simple operation and short processing time, reduce the cost of processing the photoresist resin, and have broad application prospects and good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a schematic structural diagram of the purification system of the photoresist resin of the present invention.

[0059] Figure numerals: 1: photoresist resin storage bottle; 2: multi-channel precision peristaltic pump; 3: ultra-clean silicone tube; 4: photoresist resin first purification unit; 5: pipeline; 6: valve; 7: photoresist resin second purification unit; 8: filter; 9: photoresist resin recovery bottle. DETAILED DESCRIPTION

[0060] The present invention will be described in further detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0061] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; the reagents, materials, etc. used in the following examples, unless otherwise specified, can be obtained from commercial channels.

[0062] The metal impurities in the photoresist resin to be treated used in the following embodiments include, but are not limited to, Li, Na, Mg, Al, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Pd, Ag, Cd, Sn, Au and Pb, and the total content of the metal impurities is 100 ppm.

[0063] The moisture content of the photoresist resin to be treated used in the following examples is 8%.

[0064] In the following examples, the metal impurities and water content in the purified photoresist resin were tested by ICP-MS and Karl Fischer test, respectively.

[0065] The photoresist resin paste in the following examples is prepared by the following method: dissolving the obtained photoresist resin powder in a PGMEA organic solvent to form a photoresist resin paste containing 30% PGMEA.

[0066] The film retention rates in the following examples are obtained by testing using the following method:

[0067] The obtained photoresist resin powder is dissolved in a PGMEA organic solvent to form a photoresist resin glue solution containing 30% PGMEA. The photoresist resin glue solution containing 30% PGMEA is subjected to pre-baking, development and post-baking to measure the film retention rate.

[0068] The chromatography column used in the following examples had an inner diameter of 100 mm and a length of 1 m.

[0069] The purification columns filled with mixed resin used in the following examples are all purification columns that have been rinsed with anhydrous methanol five times. The specific rinsing process is as shown in Preparation Example 1.

[0070] Preparation Example 1

[0071] A strong acidic 1200Na cation exchange resin and a strong alkaline 4200Cl anion exchange resin were selected and mixed in a mass ratio of 1:2 between the strong acidic cation exchange resin and the strong alkaline anion exchange resin, and then a Lewis acid (aluminum chloride) accounting for 2% of the total mass of the anion exchange resin and the cation exchange resin was added to the mixture, and a mixed resin was obtained after curing at 120°C for 4 hours. 1 kg of the mixed resin prepared above was weighed and filled into a chromatography column with an inner diameter of 100 mm and a length of 1 m to obtain a purification column.

[0072] The purification column was statically flushed with 1 L of anhydrous methanol, and the flushing was repeated 6 times. The water content of the filtrate was measured with a Karl Fischer instrument.

[0073] Table 1 Water content of filtrate of mixed resin after different washing times

[0074] Flushing times Sample weight 1(g) Moisture value1(%) Sample weight 2(g) Moisture value 2(%) Average moisture content (%) 1 0.00936 61.59 0.00924 61.81 61.70 2 0.00858 19.19 0.00837 20.31 19.75 3 0.00571 6.72 0.00661 6.80 6.76 4 0.00657 3.64 0.00693 3.87 3.76 5 0.22465 1.1 0.21201 1.2 1.2 6 0.21453 0.4 0.21101 0.5 0.4

[0075] Experiments have shown that the more times the washing is done, the more fully the methanol replaces the water in the mixed resin, and the water content of the filtrate will gradually decrease. After washing with anhydrous methanol for 5 times, the water content of the filtrate is 1.2%, which can be used for the purification of photoresist resin. After washing for 6 times, the water content of the filtrate is 0.4%, which is better for the purification of photoresist resin.

[0076] Example 1

[0077] The present embodiment provides a purification system for photoresist resin, the purification system comprising a first photoresist resin purification unit 4, a multi-channel precision peristaltic pump 2, a second photoresist resin purification unit 7 and a filter 8; the first photoresist resin purification unit 4, the second photoresist resin purification unit 7 and the filter 8 are connected in sequence; the first photoresist resin purification unit 4 comprises a first chromatography column; the second photoresist resin purification unit 7 comprises a second chromatography column, a third chromatography column, a fourth chromatography column and a fifth chromatography column connected in sequence.

[0078] The method for using the purification system includes: placing the photoresist resin to be treated in a photoresist resin storage bottle 1, injecting the photoresist resin to be treated into the top of the first chromatography column of the photoresist resin first purification unit 4 through an ultra-clean silicone tube 3 through a multi-channel precision peristaltic pump 2, the chromatographic photoresist resin flows out from the bottom of the first chromatography column and is injected into the photoresist resin second purification unit 7 through a pipeline 5, the photoresist resin after chromatography through four sequentially connected chromatography columns is separated from the photoresist resin second purification unit 7 and injected into a filter 8, and then injected into a photoresist resin recovery bottle 9 after filtration.

[0079] The photoresist resin collected in the photoresist resin recovery bottle 9 is subjected to sedimentation treatment using a precipitant n-heptane, and then the solid photoresist resin is collected after filtering treatment, and then the precipitant n-heptane is removed by vacuum drying to obtain a photoresist resin powder.

[0080] Example 2

[0081] In the four chromatography columns in the second purification unit 7 of the photoresist resin in the purification system of Example 1, 1 kg of strong acid type 1200 Na cationic resin was added respectively to purify 1 L of photoresist resin. The content of metal impurities in the obtained photoresist resin powder was 5 ppm; the content of water was 0.7%; and the film retention rate of the photoresist resin glue formed by the photoresist resin powder was 0%.

[0082] 1 kg of the mixed resin prepared in Preparation Example 1 was added to each of the four chromatography columns in the second photoresist resin purification unit 7 of the purification system of Example 1 to purify 1 L of photoresist resin. The content of metal impurities in the obtained photoresist resin powder was 1.5 ppm; the content of water was 0.5%; and the film retention rate of the photoresist resin glue solution formed by the photoresist resin powder was 40%.

[0083] 1 kg of microporous molecular sieve was added to the chromatography column in the first purification unit 4 of the photoresist resin in the purification system of Example 1, and 1 kg of the mixed resin prepared in Preparation Example 1 was added to each of the four chromatography columns in the second purification unit 7 of the photoresist resin in the purification system of Example 1 to purify 1 L of photoresist resin. The content of metal impurities in the obtained photoresist resin powder was 800 ppb; the content of water was 0.3%; and the film retention rate of the photoresist resin glue formed by the photoresist resin powder was 70%.

[0084] 1 kg of macroporous adsorption resin was added to the chromatography column in the first purification unit 4 of the photoresist resin in the purification system of Example 1, and 1 kg of the mixed resin prepared in Preparation Example 1 was added to each of the four chromatography columns in the second purification unit 7 of the photoresist resin in the purification system of Example 1 to purify 1 L of photoresist resin. The content of metal impurities in the obtained photoresist resin powder was 600 ppb; the content of water was 0.4%; and the film retention rate of the photoresist resin glue formed by the photoresist resin powder was 75%.

[0085] 1 kg of mesoporous adsorption resin was added to the chromatography column in the first purification unit 4 of the photoresist resin in the purification system of Example 1, and 1 kg of the mixed resin prepared in Preparation Example 1 was added to each of the four chromatography columns in the second purification unit 7 of the photoresist resin in the purification system of Example 1 to purify 1 L of photoresist resin. The content of metal impurities in the obtained photoresist resin powder was 800 ppb; the content of water was 0.3%; and the film retention rate of the photoresist resin glue formed by the photoresist resin powder was 70%.

[0086] In the chromatographic column of the first photoresist resin purification unit 4 in the purification system of Example 1, 0.5 kg of microporous molecular sieve and 0.5 kg of macroporous adsorption resin were added, and 1 kg of the mixed resin prepared in Preparation Example 1 was added to each of the four chromatographic columns in the second photoresist resin purification unit 7 in the purification system of Example 1 to purify 1 L of photoresist resin. The content of metal impurities in the obtained photoresist resin powder was 500 ppb; the content of water was 0.2%; and the film retention rate of the photoresist resin glue formed by the photoresist resin powder was 80%.

[0087] In the purification system of Example 1, 0.5 kg of microporous molecular sieve and 0.5 kg of mesoporous adsorption resin were added to the chromatography column in the first purification unit 4 of the photoresist resin, and 1 kg of the mixed resin prepared in Preparation Example 1 was added to each of the four chromatography columns in the second purification unit 7 of the photoresist resin in the purification system of Example 1 to purify 1 L of photoresist resin. The content of metal impurities in the obtained photoresist resin powder was 600 ppb; the content of water was 0.08%; and the film retention rate of the photoresist resin glue formed by the photoresist resin powder was 80%.

[0088] In the chromatographic column of the first photoresist resin purification unit 4 in the purification system of Example 1, 0.5 kg of macroporous adsorption resin and 0.5 kg of mesoporous adsorption resin were added, and 1 kg of the mixed resin prepared in Preparation Example 1 was added to each of the four chromatographic columns in the second photoresist resin purification unit 7 in the purification system of Example 1 to purify 1 L of photoresist resin. The content of metal impurities in the obtained photoresist resin powder was 500 ppb; the content of water was 0.08%; and the film retention rate of the photoresist resin glue formed by the photoresist resin powder was 80%.

[0089] In the chromatographic column of the first photoresist resin purification unit 4 in the purification system of Example 1, 0.25 kg of macroporous adsorption resin, 0.25 kg of mesoporous adsorption resin and 0.5 kg of microporous adsorption resin were added, and 1 kg of the mixed resin prepared in Preparation Example 1 was added to each of the four chromatographic columns in the second photoresist resin purification unit 7 in the purification system of Example 1 to purify 1 L of photoresist resin. The content of metal impurities in the obtained photoresist resin powder was 100 ppb; the content of water was 0.03%; and the film retention rate of the photoresist resin glue formed by the photoresist resin powder was 96%.

[0090] The above examples are used to illustrate the specific implementation of the present invention. However, the protection scope of the present invention is not limited to the above exemplary implementation. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for purifying a photoresist resin, characterized in that: The purification method comprises: The photoresist resin to be treated is passed through a first purification unit and a second purification unit in sequence; wherein the first purification unit includes an adsorption resin and / or a molecular sieve; the second purification unit includes a mixed resin; the mixed resin is a resin formed by mixing a cation exchange resin and an anion exchange resin.

2. The purification method according to claim 1, characterized in that The photoresist resin is KrF photoresist resin.

3. The purification method according to claim 1 or 2, characterized in that The photoresist resin to be treated contains metal impurities; the total content of metal impurities in the photoresist resin to be treated is not less than 10ppm; And / or, the photoresist resin to be treated contains moisture; the moisture content in the photoresist resin to be treated is not less than 2%.

4. The purification method according to any one of claims 1 to 3, characterized in that The adsorption resin is selected from at least one of a mesoporous adsorption resin, a microporous adsorption resin and a macroporous adsorption resin.

5. The purification method according to any one of claims 1 to 4, characterized in that The cation exchange resin is a strong acid cation exchange resin; And / or, the anion exchange resin is a strong base anion exchange resin; Preferably, the mass ratio of the cation exchange resin to the anion exchange resin in the mixed resin is 1:1.5-4.

6. The purification method according to any one of claims 1 to 5, characterized in that The mixed resin is prepared by the following method: The mixed resin is prepared by mixing Lewis acid, cation exchange resin and anion exchange resin, and heating and curing.

7. The purification method according to any one of claims 1 to 6, characterized in that The purification method further comprises filtering, that is, filtering the photoresist resin after being processed by the second purification unit.

8. The purification method according to any one of claims 1 to 7, characterized in that The purification method further comprises: using a precipitant n-heptane to precipitate the purified photoresist resin, then collecting the solid photoresist resin after filtering, and then removing the precipitant n-heptane through vacuum drying to obtain photoresist resin powder.

9. The purification method according to any one of claims 1 to 8, characterized in that The content of total metal impurities in the photoresist resin is less than or equal to 1000 ppb; and the water content in the photoresist resin is less than or equal to 0.4%. Preferably, the film retention rate of the photoresist resin solution is not less than 70%.

10. A purification system for photoresist resin, the purification system comprising a first purification unit for photoresist resin, a multi-channel precision peristaltic pump, a second purification unit for photoresist resin and a filter; The first photoresist resin purification unit, the second photoresist resin purification unit and the filter are connected in sequence; The first photoresist resin purification unit includes adsorption resin and / or molecular sieve; the second photoresist resin purification unit includes mixed resin; the mixed resin is a resin formed by mixing a cation exchange resin and an anion exchange resin.

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