Star-shaped polymer photoresist film-forming resin as well as preparation method and application thereof

Abstract

The invention discloses star-shaped polymer photoresist film-forming resin as well as a preparation method and application thereof, and belongs to the technical field of polymer synthetic materials. The structure of the star-shaped polymer photoresist film-forming resin provided by the invention is shown as a formula (I): # imgabs0 #, and # imgabs1 # R1 is selected from one of a hydrogen atom and methyl; r2 is selected from one of carbonate, ester and ether; r3 is selected from one of alkyl or unit alicyclic ring; x, y and z are positive integers, and the sum of x, y and z is the polymerization degree of the copolymer; the number-average molecular weight of the star-shaped polymer photoresist film-forming resin is 3000 to 60000. The film-forming resin provided by the invention is controllable in molecular weight, narrow in molecular weight distribution and higher in photosensitive group content, and the resolution of photoresist can be greatly improved; the molecular chain fluid volume is lower, the chain entanglement degree is reduced, and the roughness can be obviously optimized; the photoresist composition can be well exposed under the condition of 365 nm, so that the prepared photoresist composition has a wide application prospect in a photoetching technology.

Description

Technical Field

[0001] The present application belongs to the technical field of polymer synthetic materials, and in particular relates to a star polymer photoresist film-forming resin and a preparation method and application thereof. Background Art

[0002] Photolithography refers to the process of transferring the pattern on the mask to the wafer using a photochemical combined with etching method during the manufacturing of integrated circuits, and photoresist is the core material of this process. Photoresist is a mixed liquid that is highly sensitive to light. Its main components include a main resin, a sensitizer, and a solvent. Its photosensitive properties cause the exposed area to react chemically under light, showing a difference in solubility in alkaline solution from the non-exposed part. After solvent treatment, the soluble part is removed to form the desired image.

[0003] Driven by Moore's Law, the wavelength of the exposure light source required for the photolithography process is constantly shortened, and higher requirements are also placed on the sensitivity, roughness and resolution of the photoresist. Polymer photoresist has become the most widely used type of resin due to its excellent film-forming properties and mature process flow. Its main resin is usually synthesized by free radical polymerization. For example, the prior art with application publication number CN 115991815 A discloses a dendritic polymer positive photoresist resin, which improves the etching resistance of the resin.

[0004] However, the products obtained by traditional free radical polymerization have the following problems: 1) The molecular weight distribution is wide. The wider molecular weight distribution directly affects the roughness and sensitivity during the dissolution process; 2) The molecular chain topology is difficult to control. Most polymers obtained by traditional free radical polymerization have a linear structure, which reduces the density of photosensitive groups and limits the improvement of photoresist performance; 3) It is difficult to ensure the consistency of different batches of resins, which poses a huge challenge to production stability. Summary of the invention

[0005] The purpose of this application is to disclose a star polymer photoresist film-forming resin and its preparation method and application, aiming to solve the technical problems of the existing photoresist resin, such as wide molecular weight distribution, difficult to control molecular chain topological structure and poor photoresist performance.

[0006] In order to achieve the above purpose, the technical solution of this application is:

[0007] The first aspect of the present application provides a star polymer photoresist film-forming resin, the structure of which is shown in formula (I):

[0008]

[0009] in, R 1 is selected from a hydrogen atom and a methyl group; R 2is selected from one of carbonate, ester and ether; R 3 is selected from one of an alkyl group or alicyclic unit; x, y, z are positive integers, and the sum of the three is the degree of polymerization of the copolymer;

[0010] The number average molecular weight of the star polymer photoresist film-forming resin is 3000-60000.

[0011] In combination with the first aspect, preferably, the R 2 A group selected from formula (II)-(VI).

[0012]

[0013] In combination with the first aspect, preferably, the R 3 A group selected from formula (VII) to (XIII).

[0014]

[0015] The second aspect of the present application provides a method for preparing the star polymer photoresist film-forming resin according to the first aspect, the preparation method comprising:

[0016] Styrene, 4-acetoxystyrene, tert-butyl acrylate, RAFT agent and initiator are dissolved in a first solvent for reaction, and then transferred into a second solvent for sedimentation and filtration to obtain a star copolymer resin P-1;

[0017] The star copolymer resin P-1 and ammonia water are added to a first solvent for deacetylation, and after evaporation of the solvent, the star polymer photoresist film-forming resin is obtained.

[0018] In combination with the second aspect, preferably, the molar ratio of styrene, 4-acetoxystyrene and tert-butyl acrylate is (10-30): (40-70): (15-30).

[0019] In combination with the second aspect, preferably, the structure of the RAFT agent is as shown in formula (XIV):

[0020]

[0021] Formula (XIV)

[0022] The initiator is one or more of azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanenitrile, azoisobutylcyanoformamide, and dimethyl azobisisobutyrate;

[0023] The molar ratio of the RAFT agent to the initiator is (2-10):1.

[0024] In combination with the second aspect, preferably, the first solvent is one or more of dichloromethane, chloroform, propylene glycol monomethyl ether acetate, tetrahydrofuran, toluene, acetone, dioxane, dichloroethane, trichloroethane, xylene, and methyl ethyl ketone;

[0025] The second solvent is one of n-hexane or methanol.

[0026] In combination with the first aspect, preferably, when styrene, 4-acetoxystyrene, tert-butyl acrylate, RAFT agent and initiator are dissolved in the first solvent for reaction, the reaction temperature is 60-125° C. and the reaction time is 4-36 h.

[0027] The third aspect of the present application provides a photoresist composition, comprising an organic solvent, a photosensitizer dissolved in the organic solvent, and the star polymer photoresist film-forming resin of the first aspect;

[0028] Wherein, the photosensitizer is one of triphenylsulfonium perfluorobutyl sulfonate, triphenylsulfonium trifluoromethyl sulfonate, di(4-tert-butylphenyl)iodonium perfluorobutyl sulfonate, and di(4-tert-butylphenyl)iodonium camphorquinone sulfonate;

[0029] The mass fraction of the photosensitizer is 1-15%;

[0030] The mass fraction of the star polymer photoresist film-forming resin is 5-30%.

[0031] The fourth aspect of the present application provides application of the photoresist composition described in the third aspect in photolithography technology.

[0032] Compared with the prior art, the advantages or beneficial effects of the embodiments of the present application include at least:

[0033] The star polymer photoresist film-forming resin provided in the present application has a relatively uniform and regular four-arm star structure; on the one hand, it has a higher content of photosensitive groups, which can greatly improve the resolution of the photoresist, and has a narrow molecular weight distribution and a uniform system, which helps to further improve the resolution of the photoresist; on the other hand, it has a lower molecular chain fluid volume, reduces the degree of chain entanglement, and can significantly optimize the roughness; at the same time, it can make the prepared photoresist composition have broad application prospects in photolithography technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 (CTA-Z) provided in the embodiment of the present application 4 1H NMR spectrum;

[0036] Figure 2 This is the hydrogen NMR spectrum of the A1-film-forming resin P-1 provided in the examples of the present application;

[0037] Figure 3 Infrared spectra of A1-film-forming resin P-1 and A1-film-forming resin provided in the examples of the present application;

[0038] Figure 4 This is a photolithographic image after development of the A1-film-forming resin provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] In the following description of this embodiment, the term "and / or" is used to describe the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0041] In the following description of this embodiment, the term "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b or c", or "at least one of a, b and c", can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0042] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0043] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0044] It should be noted that all raw materials and reagents in the examples of the present application were purchased on the market or prepared according to conventional methods well known to those skilled in the art.

[0045] In a first aspect, the present application provides a star polymer photoresist film-forming resin, the structure of which is shown in formula (I):

[0046]

[0047] in, R 1 is selected from a hydrogen atom and a methyl group; R 2 is selected from one of carbonate, ester and ether; R 3 It is selected from one of an alkyl group or a unit alicyclic ring; x, y, and z are positive integers, and the sum of the three is the degree of polymerization of the copolymer; the number average molecular weight of the star polymer photoresist film-forming resin is 3000-60000.

[0048] Among them, on the one hand, it has a higher content of photosensitive groups, which can greatly improve the resolution of the photoresist, and the narrow molecular weight distribution and uniform system are helpful to further improve the resolution of the photoresist; on the other hand, it has a lower molecular chain fluid volume, reduces the degree of chain entanglement, and can significantly optimize the roughness, so that the prepared photoresist composition has broad application prospects in photolithography technology.

[0049] In the present application, R 1 Preferably, it is a hydrogen atom or a methyl group, more preferably a hydrogen atom; R 2 Preferably, it is one selected from carbonate, ester and ether, preferably one of formula (II)-(VI), more preferably formula (VI); wherein these groups are acid / base catalyzed alcoholysable protecting groups.

[0050]

[0051] In the present application, R 3 Preferably, it is one of an alkyl group or a single alicyclic group, more preferably one of (VII)-(XIII), and more preferably formula (VII); wherein, these groups have a large steric hindrance, which can greatly increase the irregularity of the molecular chain, thereby improving the solubility of the polymer, which has a great advantage in preparing a thicker photoresist film. In addition, some of these groups contain strong polar groups, which can enhance the wettability with the developer and accelerate the development process.

[0052]

[0053] In a second aspect, the present application also provides a method for preparing the star polymer photoresist film-forming resin according to the first aspect, the preparation method comprising:

[0054] Styrene, 4-acetoxystyrene, tert-butyl acrylate, RAFT agent and initiator are dissolved in a first solvent for reaction, and then transferred into a second solvent for sedimentation and filtration to obtain a copolymer resin P-1;

[0055] The copolymer resin P-1 and ammonia water are added into a first solvent for deacetylation, and after evaporation of the solvent, the star polymer photoresist film-forming resin is obtained.

[0056] It should be noted that the reaction formula of the copolymer resin P-1 prepared in this application is:

[0057]

[0058] in, x, y, z are positive integers, and the sum of the three is the degree of polymerization of the copolymer.

[0059] It should be noted that the specific source of the RAFT agent in the embodiments of the present application is not particularly limited, and it can be synthesized by commercial routes or methods known in the art. For example, the embodiment of the present application is synthesized by reference (Z-RAFT star polymerization of styrene: Comprehensive characterization using size-exclusion chromatography, Polymer 49 (2008) 5199-5208). The synthesis steps used in the present application are: potassium phosphate and acetone are weighed and stirred in a single-mouth round-bottom flask for 0.5 hours, and then cooled in an ice bath. 1-Butanethiol is slowly added dropwise to the suspension and continued to stir for 30 minutes. At 5°C, a mixture of carbon disulfide and acetone is slowly dripped in, stirred for 1 hour, and then warmed to room temperature and continued to stir for 12 hours. The flask is then placed back in an ice bath, and a mixture of 1,2,4,5-tetrabromomethylbenzene and acetone is added dropwise, and the mixture is returned to room temperature and stirred overnight. After the reaction is completed, the solvent is removed by rotary evaporation, and the residue is dissolved in dichloromethane, washed with water, and dried over anhydrous sodium sulfate. Finally, sodium sulfate and water were removed by filtration and rotary evaporation, and the crude product was purified by silica gel column chromatography to obtain four-arm Z / Group RAFT agent (CTA-Z) 4 .

[0060] It should be noted that the prepared copolymer resin P-1 and ammonia water are added to the first solvent for deacetylation. Since the environmental stability of hydroxystyrene is poor and the phenolic hydroxyl group is difficult to exist stably, 4-acetoxystyrene is selected. Therefore, the intermediate product copolymer resin P-1 needs to be deacetylated to expose the phenolic hydroxyl group to achieve a polymer resin that meets the requirements of photolithography. The reaction equation is:

[0061]

[0062] in, R 1 is selected from a hydrogen atom and a methyl group; R 2 is selected from one of carbonate, ester and ether; R 3 It is selected from one of an alkyl group and a unit alicyclic ring; x, y, and z are positive integers, and the sum of the three is the degree of polymerization of the copolymer.

[0063] In the embodiment of the present application, the molar ratio of styrene, 4-acetoxystyrene and tert-butyl acrylate is preferably (10-30): (40-70): (15-30). By controlling the molar amount of each monomer added, the reaction degree of the functional group in the polymerization reaction and the chain length of the polymer can be determined, thereby effectively controlling the molecular weight of the generated resin.

[0064] It should be noted that there are two strategies for the different growth modes of star polymer arms, namely the "core first strategy" and the "arm first strategy", and the corresponding RAFT agents are Z / Group and R / Group, respectively. The "core first strategy" is to first synthesize a multifunctional monomer and use it as the core, and then add monomers to the system to complete the arm growth. This method can obtain a star polymer with a certain number of arms and arm end groups, which is easier to control, but the arm length is not easy to control consistently. The "arm first strategy" is to first synthesize an arm with a certain degree of polymerization, grow toward the core, and complete the assembly of the star polymer. This method can obtain a certain arm length, but the number of arms may not be fully controlled due to steric effects. At the same time, the RAFT agent at the arm end may produce bridging and other phenomena, thereby widening the molecular weight distribution. Therefore, after optimization, the Z / Group RAFT agent was selected to complete the synthesis of the star polymer with the "core first strategy".

[0065] In the embodiment of the present application, the initiator is preferably one or more of azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanenitrile, azoisobutylcyanoformamide, and dimethyl azobisisobutyrate; the molar ratio of the RAFT agent to the initiator is preferably (2-10): 1, and the solid content of the system during the reaction is preferably 10-40%. Among them, the main function of the RAFT agent is to control the chain transfer process of the polymerization reaction, thereby achieving active polymerization. The initiator determines the initial free radical concentration of the polymerization reaction, which in turn affects the polymerization rate. By controlling the molar ratio of the RAFT agent to the initiator, the chain transfer and chain growth reactions can be balanced, thereby optimizing the kinetic process of the polymerization reaction.

[0066] In the embodiment of the present application, the first solvent is preferably one or more of dichloromethane, chloroform, propylene glycol monomethyl ether acetate, tetrahydrofuran, toluene, acetone, dioxane, dichloroethane, trichloroethane, xylene, and methyl ethyl ketone; the second solvent is preferably n-hexane or methanol. Among them, these first solvents can achieve uniform and stable dissolution of raw materials; sedimentation filtration and collection in the second solvent can separate the resin from the mixed solution after the reaction, and can be collected by sedimentation filtration multiple times to obtain a purer polymer resin.

[0067] In the embodiment of the present application, when styrene, 4-acetoxystyrene, tert-butyl acrylate, RAFT agent and initiator are dissolved in the first solvent for reaction, the reaction temperature is preferably 60-125° C., and the reaction time is preferably 4-36 hours. Among them, by controlling the reaction time and temperature, the reaction degree of the polymerization reaction can be effectively controlled, and then the molecular weight of the generated resin can be effectively controlled.

[0068] It should be noted that the star polymer photoresist film-forming resin prepared in the present application is a series of star terpolymer photoresist resins composed of a Z-group RAFT agent as a core and arms, which are prepared in a core-first manner. The copolymers have different monomer compositions, arm numbers, arm lengths, and controllable molecular weights and narrow molecular weight distributions, overcoming the limitations of traditional free radical polymerization. By being configured into a photoresist composition, high-quality photolithographic patterns can be obtained.

[0069] It should be noted that the molecular weight distribution PDI of the star polymer photoresist film-forming resin is between 1.1 and 1.5. It is prepared by RAFT polymerization and then deacetylated under alkaline solution to expose the phenolic hydroxyl groups. The final result is a controllable molecular weight, narrow molecular weight distribution, simple and mild reaction conditions, and is suitable for exposure at 365nm. It is expected to provide a certain research basis for the synthesis and preparation of photoresist film-forming resins required for deep ultraviolet and even extreme ultraviolet lithography processes.

[0070] In a third aspect, the present application further provides a photoresist composition, comprising an organic solvent, a photosensitizer dissolved in the organic solvent, and the star polymer photoresist film-forming resin described in the first aspect; wherein the photosensitizer is one of triphenylsulfonium perfluorobutyl sulfonate, triphenylsulfonium trifluoromethyl sulfonate, di(4-tert-butylphenyl)iodonium perfluorobutyl sulfonate, and di(4-tert-butylphenyl)iodonium camphorquinone sulfonate;

[0071] The mass fraction of the photosensitizer is 1-15%;

[0072] The mass fraction of the star polymer photoresist film-forming resin is 5-30%.

[0073] It should be noted that, in the present application, the prepared photoresist composition is subjected to 365nm ultraviolet contact exposure and then developed with a developer. The developer used here can be selected from various alkaline aqueous solutions, and the optional developer includes aqueous solutions of compounds such as tetramethylammonium hydroxide, trimethyl-2-hydroxyethylammonium hydroxide, sodium hydroxide, potassium hydroxide, etc., and tetramethylammonium hydroxide is more preferred.

[0074] In a fourth aspect, the present application also provides an application of the photoresist composition in photolithography. Based on the film-forming resin described above having controllable molecular weight and narrow molecular weight distribution, the prepared photoresist composition is applied to positive photoresist, so that the sensitivity, film retention rate, heat resistance, contrast, resolution, production capacity and other properties of the photoresist can be improved at the same time, significantly improving the quality of the photolithography pattern.

[0075] The technical solution of the present application will be further described below in conjunction with specific embodiments.

[0076] Example 1

[0077] This embodiment provides a method for preparing A1-film-forming resin, which specifically comprises:

[0078] Synthesis of Z / group RAFT agent: Weigh potassium phosphate (12.7 g, 0.06 mol) and 200 mL acetone in a 500 mL single-mouth round-bottom flask, stir for 0.5 hours, and cool in an ice bath. Slowly add 1-butanethiol (5.40 g, 0.06 mol) to the suspension and continue stirring for 30 minutes. At 5 ° C, slowly drip a mixture of carbon disulfide (13.7 g, 0.18 mol) and 50 mL acetone, stir for 1 hour, warm to room temperature, and continue stirring for 12 hours. Then put the flask back in an ice bath, add a mixture of 1,2,4,5-tetrabromomethylbenzene (4.49 g, 0.01 mol) and 50 mL acetone dropwise, return to room temperature and stir overnight. After the reaction is completed, the solvent is removed by rotary evaporation, and the residue is dissolved in dichloromethane, washed with water, and dried over anhydrous sodium sulfate. Finally, sodium sulfate and water were removed by suction filtration and rotary evaporation, and the crude product was purified by silica gel column chromatography to obtain four-arm Z / Group RAFT agent (CTA-Z) 4 .

[0079] S101: Weigh 0.649g of styrene, 2.6763g of 4-acetoxystyrene, 0.9615g of tert-butyl acrylate, 0.346g of Z / Group tetrafunctional macromolecular RAFT agent, and 0.016g of azobisisobutyronitrile and add them in sequence to a 25mL polymerization tube, then add 7.92g of solvent propylene glycol methyl ether acetate and stir evenly. Perform cryo-evacuation 3 times to exhaust the gas in the system, fill with nitrogen for 10s, and maintain an inert gas atmosphere. Thermal initiation is carried out in a 70°C oil bath and maintained for 12h. After the reaction is completed, quench with liquid nitrogen and open the polymer sample to contact with the air to terminate the reaction. The polymer is precipitated and filtered in n-hexane, the precipitate is dissolved in the solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A1-film-forming resin P-1;

[0080] The number average molecular weight M of the A1-film-forming resin P-1 was measured by GPC. n is 8500, A1-film-forming resin P-1 molecular weight distribution PDI is 1.13;

[0081] S102: Weigh 1g of A1-film-forming resin P-1, add 3 times the molar equivalent of 25% concentration of ammonia water and 2g of anhydrous methanol, stir evenly, maintain a nitrogen atmosphere, and react at 80°C for 6h. As the reaction proceeds, the yellow powder in the system gradually disappears and turns into a transparent solution. After the reaction is completed, use a rotary evaporator to spin dry the system solvent, and use a precipitation method to post-treat the product. The polymer is precipitated and filtered in n-hexane, and the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A1-film-forming resin.

[0082] GPC measured the number average molecular weight M of A1-film-forming resinn The molecular weight distribution PDI is 1.21. The structure of the film-forming resin A1 is shown in formula (XV):

[0083]

[0084] Example 2

[0085] This embodiment provides a method for preparing A2-film-forming resin, which specifically includes:

[0086] S201: Weigh 1.041g of styrene, 4.4605g of 4-acetoxystyrene, 1.6025g of tert-butyl acrylate, 0.346g of Z / Group tetrafunctional macromolecular RAFT agent, and AIBN (0.0039g, 0.02mmol) and add them in sequence to a 25mL polymerization tube, then add 13.83g of propylene glycol methyl ether acetate solvent and stir evenly. Perform cryo-evacuation 3 times to exhaust the gas in the system, fill with nitrogen for 10s, and maintain an inert gas atmosphere. Thermal initiation is carried out in a 70°C oil bath and maintained for 12h. After the reaction is completed, liquid nitrogen is quenched and the polymer sample is opened to contact with the air to terminate the reaction. The polymer is precipitated and filtered in n-hexane, the precipitate is dissolved in tetrahydrofuran solvent, precipitated again in n-hexane, and dried in a vacuum oven to obtain A2-film-forming resin P-1;

[0087] The number average molecular weight M of the A2-film-forming resin P-1 was measured by GPC. n is 13400, and the molecular weight distribution PDI is 1.34;

[0088] S202: Weigh 1g A2-film-forming resin P-1, add 3 times the molar equivalent of 25% concentration of ammonia water and 2g of anhydrous methanol, stir evenly, maintain a nitrogen atmosphere, and react at 80°C for 6h. As the reaction proceeds, the yellow powder in the system gradually disappears and turns into a transparent solution. After the reaction, use a rotary evaporator to spin dry the system solvent, and use a precipitation method to post-treat the product. The polymer is precipitated and filtered in n-hexane, and the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A2-film-forming resin.

[0089] The number average molecular weight M of the A2-film-forming resin was measured by GPC. n The molecular weight distribution PDI is 1.3. The molecular structure of A2-film-forming resin is basically the same as that of A1-film-forming resin.

[0090] Example 3

[0091] This embodiment provides a method for preparing A3-film-forming resin, which specifically includes:

[0092] S301: Weigh 0.649g of styrene, 2.6763g of 4-acetoxystyrene, 0.9615g of tert-butyl acrylate, 0.346g of Z / Group-type tetrafunctional macromolecular RAFT agent, and 0.016g of azobisisobutyronitrile and add them in sequence to a 25mL polymerization tube, then add 7.92g of solvent propylene glycol methyl ether acetate and stir evenly. Perform cryo-evacuation 3 times to exhaust the gas in the system, fill with nitrogen for 10s, and maintain an inert gas atmosphere. Thermal initiation is carried out in a 70°C oil bath for 24h. After the reaction is completed, liquid nitrogen is quenched and the polymer sample is opened to contact with air to terminate the reaction. The polymer is precipitated and filtered in n-hexane, the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A3-film-forming resin P-1.

[0093] The number average molecular weight M of the A3-film-forming resin P-1 was measured by GPC. n The molecular weight distribution PDI is 1.13.

[0094] S302: Weigh 1g A3-film-forming resin P-1, add 3 times the molar equivalent of 25% concentration of ammonia water and 2g of anhydrous methanol, stir evenly, maintain a nitrogen atmosphere, and react at 80°C for 6h. As the reaction proceeds, the yellow powder in the system gradually disappears and turns into a transparent solution. After the reaction is completed, use a rotary evaporator to spin dry the system solvent, and use a precipitation method to post-treat the product. The polymer is precipitated and filtered in n-hexane, and the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A3-film-forming resin.

[0095] The number average molecular weight M of the A3-film-forming resin was measured by GPC. n The molecular weight distribution PDI is 1.12. The molecular structure of A3-film-forming resin is basically the same as that of A1-film-forming resin.

[0096] Example 4

[0097] This embodiment provides a method for preparing A4-film-forming resin, which specifically includes:

[0098] S401: Weigh 0.6275g of styrene, 2.675g of 4-acetoxystyrene, 0.9704g of tert-butyl acrylate, 0.577g of Z / Group-type tetrafunctional macromolecular RAFT agent, and 0.016g of azobisisobutyronitrile and add them in sequence to a 25mL polymerization tube, then add 8.0g of solvent propylene glycol methyl ether acetate and stir evenly. Perform cryo-evacuation 3 times to exhaust the gas in the system, fill with nitrogen for 10s, and maintain an inert gas atmosphere. Thermal initiation is carried out in a 70°C oil bath for 24h. After the reaction is completed, liquid nitrogen is quenched and the polymer sample is opened to contact with air to terminate the reaction. The polymer is precipitated and filtered in n-hexane, the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A4-film-forming resin P-1.

[0099] The number average molecular weight M of the A4-film-forming resin P-1 was measured by GPC. n The molecular weight distribution PDI is 1.1.

[0100] S402: Weigh 1g A4-film-forming resin P-1, add 3 times the molar equivalent of 25% concentration of ammonia water and 2g of anhydrous methanol, stir evenly, maintain a nitrogen atmosphere, and react at 80°C for 6h. As the reaction proceeds, the yellow powder in the system gradually disappears and turns into a transparent solution. After the reaction is completed, use a rotary evaporator to spin dry the system solvent, and use a precipitation method to post-treat the product. The polymer is precipitated and filtered in n-hexane, and the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A4-film-forming resin.

[0101] The number average molecular weight M of the A4-film-forming resin was measured by GPC. n The molecular weight distribution PDI is 1.09.

[0102] Example 5

[0103] This embodiment provides a method for preparing A5-film-forming resin, which specifically includes:

[0104] S501: Weigh 1.255g of styrene, 5.35g of 4-acetoxystyrene, 1.9408g of tert-butyl acrylate, 0.1154g of Z / Group-type tetrafunctional macromolecular RAFT agent, and 0.0052g of azobisisobutyronitrile and add them in sequence to a 25mL polymerization tube, then add 16.0g of solvent propylene glycol methyl ether acetate and stir evenly. Perform cryo-evacuation 3 times to exhaust the gas in the system, fill with nitrogen for 10s, and maintain an inert gas atmosphere. Thermal initiation is carried out in a 70°C oil bath for 24h. After the reaction is completed, liquid nitrogen is quenched and the polymer sample is opened to contact with air to terminate the reaction. The polymer is precipitated and filtered in n-hexane, the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A5-film-forming resin P-1.

[0105] The number average molecular weight M of the A5-film-forming resin P-1 was measured by GPC. n The molecular weight distribution PDI is 1.22.

[0106] S502: Weigh 1g A5-film-forming resin P-1, add 3 times the molar equivalent of 25% concentration of ammonia water and 2g of anhydrous methanol, stir evenly, maintain a nitrogen atmosphere, and react at 80°C for 6h. As the reaction proceeds, the yellow powder in the system gradually disappears and turns into a transparent solution. After the reaction is completed, use a rotary evaporator to spin dry the system solvent, and use a precipitation method to post-treat the product. The polymer is precipitated and filtered in n-hexane, and the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A5-film-forming resin.

[0107] The number average molecular weight M of the A5-film-forming resin was measured by GPC. n The molecular weight distribution PDI is 1.2. The molecular structure of A5-film-forming resin is basically the same as that of A1-film-forming resin.

[0108] Example 6

[0109] This embodiment provides a method for preparing A6-film-forming resin, which specifically includes:

[0110] S601: Weigh 1.8825g of styrene, 8.025g of 4-acetoxystyrene, 2.9112g of tert-butyl acrylate, 0.1443g of Z / Group-type tetrafunctional macromolecular RAFT agent, and 0.004g of azobisisobutyronitrile and add them in sequence to a 50mL polymerization tube, then add 24.0g of solvent propylene glycol methyl ether acetate and stir evenly. Perform cryo-evacuation 3 times to exhaust the gas in the system, fill with nitrogen for 10s, and maintain an inert gas atmosphere. Thermal initiation is carried out in a 70°C oil bath for 24h. After the reaction is completed, liquid nitrogen is quenched and the polymer sample is opened to contact with air to terminate the reaction. The polymer is precipitated and filtered in n-hexane, the precipitate is dissolved in the solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A6-film-forming resin P-1.

[0111] The number average molecular weight M of the A6-film-forming resin P-1 was measured by GPC. n The molecular weight distribution PDI is 1.35.

[0112] S602: Weigh 1g A6-film-forming resin P-1, add 3 times the molar equivalent of 25% concentration of ammonia water and 2g of anhydrous methanol, stir evenly, maintain a nitrogen atmosphere, and react at 80°C for 6h. As the reaction proceeds, the yellow powder in the system gradually disappears and turns into a transparent solution. After the reaction, use a rotary evaporator to spin dry the system solvent, and use a precipitation method to post-treat the product. The polymer is precipitated and filtered in n-hexane, and the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A6-film-forming resin.

[0113] The number average molecular weight M of the A6-film-forming resin was measured by GPC. n The molecular weight distribution PDI is 1.32.

[0114] Example 7

[0115] This embodiment provides a method for preparing A7-film-forming resin, which specifically includes:

[0116] S701: Weigh 1.5623g of styrene, 9.7314g of 4-acetoxystyrene, 3.2043g of tert-butyl acrylate, 0.1443g of Z / Group-type tetrafunctional macromolecular RAFT agent, and 0.004g of azobisisobutyronitrile and add them in sequence to a 50mL polymerization tube, then add 24.0g of solvent propylene glycol methyl ether acetate and stir evenly. Perform cryo-evacuation 3 times to exhaust the gas in the system, fill with nitrogen for 10s, and maintain an inert gas atmosphere. Thermal initiation is carried out in a 70°C oil bath for 24h. After the reaction is completed, liquid nitrogen is quenched and the polymer sample is opened to contact with air to terminate the reaction. The polymer is precipitated and filtered in n-hexane, the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A6-film-forming resin P-1.

[0117] The number average molecular weight M of the A7-film-forming resin P-1 was measured by GPC. n The molecular weight distribution PDI is 1.37.

[0118] S702: Weigh 1g A7-film-forming resin P-1, add 3 times the molar equivalent of 25% concentration of ammonia water and 2g of anhydrous methanol, stir evenly, maintain a nitrogen atmosphere, and react at 80°C for 6h. As the reaction proceeds, the yellow powder in the system gradually disappears and turns into a transparent solution. After the reaction, use a rotary evaporator to spin dry the system solvent, and use a precipitation method to post-treat the product. The polymer is precipitated and filtered in n-hexane, and the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A7-film-forming resin.

[0119] The number average molecular weight M of the A7-film-forming resin was measured by GPC. n The molecular weight distribution PDI is 1.34.

[0120] Example 8

[0121] This embodiment provides a method for preparing A8-film-forming resin, which specifically includes:

[0122] S801: Weigh 3.1245g of styrene, 6.4876g of 4-acetoxystyrene, 3.8451g of tert-butyl acrylate, 0.1443g of Z / Group tetrafunctional macromolecular RAFT agent, and 0.004g of azobisisobutyronitrile and add them in sequence to a 50mL polymerization tube, then add 24.0g of solvent propylene glycol methyl ether acetate and stir evenly. Perform cryo-evacuation 3 times to exhaust the gas in the system, fill with nitrogen for 10s, and maintain an inert gas atmosphere. Thermal initiation is carried out in a 70°C oil bath for 24h. After the reaction is completed, liquid nitrogen is quenched and the polymer sample is opened to contact with air to terminate the reaction. The polymer is precipitated and filtered in n-hexane, the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A8-film-forming resin P-1.

[0123] The number average molecular weight M of the A8-film-forming resin P-1 was measured by GPC. n The molecular weight distribution PDI is 1.35.

[0124] S802: Weigh 1g A8-film-forming resin P-1, add 3 times the molar equivalent of 25% concentration of ammonia water and 2g of anhydrous methanol, stir evenly, maintain a nitrogen atmosphere, and react at 80°C for 6h. As the reaction proceeds, the yellow powder in the system gradually disappears and turns into a transparent solution. After the reaction is completed, use a rotary evaporator to spin dry the system solvent, and use a precipitation method to post-treat the product. The polymer is precipitated and filtered in n-hexane, and the precipitate is dissolved in solvent tetrahydrofuran, precipitated again in n-hexane, and dried in a vacuum oven to obtain A8-film-forming resin.

[0125] The number average molecular weight M of the A8-film-forming resin was measured by GPC. n The molecular weight distribution PDI is 1.34.

[0126] In order to verify the characteristic structure and properties of the film-forming resin prepared in the examples of this application, the results are Figure 1-Figure 3 As shown; among them, Figure 1 It is a four-arm Z / Group RAFT agent (CTA-Z) 4 H NMR spectrum of Figure 2 is the H-NMR spectrum of A1-film-forming resin P-1; Figure 3 It is the infrared spectra of A1-film-forming resin P-1 and A1-film-forming resin.

[0127] according to Figure 1 It can be seen that each signal peak can be assigned according to formula (XIV), and the characteristic structure of the four-arm Z / Group RAFT agent can be clearly seen, indicating that the polymerization reaction successfully prepared the four-arm Z / Group RAFT agent (CTA-Z) 4 .

[0128] according to Figure 2 It can be seen that each signal peak can be attributed, and the characteristic structure of A1-film-forming resin P-1 can be clearly seen, indicating that the intermediate product was successfully prepared in the first step of the reaction.

[0129] according to Figure 3 It can be seen that the infrared spectra of A1-film-forming resin P-1 and A1-film-forming resin have little difference in the fingerprint area, indicating that the main chain structure is basically preserved intact. -1 The carbonyl peak near 3400cm-1 almost disappeared after deprotection, indicating that the deacetylation was almost complete. -1 Nearby, the peak attributable to the hydroxyl group increased significantly after deacetylation, proving that the phenolic hydroxyl group was successfully exposed.

[0130] In order to verify the application of the film-forming resin prepared in the embodiment of the present application in the photolithography experiment: 0.5g of film-forming resin, 0.01g of PAG (triphenylsulfonium perfluorobutyl sulfonate), and propylene glycol monomethyl ether acetic acid were added to a 100mL light-proof glass bottle. At room temperature, the mixture was shaken for 24 hours to fully dissolve. The photoresist solution was filtered with 0.5 micron, 0.22 micron and 0.02 micron filters successively. Finally, the photolithography experiment was carried out.

[0131] Photolithography process: Select a 4-inch silicon wafer, place it on the platform of the glue machine in the clean bench after purging with nitrogen. Then, add 5 ml of hydrogen-terminated polydimethylsiloxane (HDMS) drop by drop, and after it is self-leveling, use a glue machine at 4000rpm for 60s, and then bake it at 60℃ for 2min on a hot stage. After baking, add the above-mentioned homemade photoresist drop by drop on the treated wafer, wait for it to be self-leveling, use a glue machine at 2000rpm for 60s, and then bake it at 100℃ for 1min on a hot stage. After baking, use a 365nm ultraviolet photolithography machine to expose for 5s. Then, use a hot stage at 120℃ to complete the 120s post-baking process, and finally, use an alkaline developer to completely immerse the wafer and treat it for 60s. After development, quickly rinse with deionized water for 30s to remove excess developer and complete the photolithography process.

[0132] according to Figure 4 It can be seen that in a) figure, the lines are straight and clear, and the pattern of the mask is well preserved; in b) figure, it can be found that the edges of the pattern are sharp and have no obvious defects, which proves that it has good resolution; in c) figure, it can be found that the lithography pattern is almost consistent with the right-angle pattern of the mask, and the contrast is high, which proves that it has excellent roughness control.

[0133] Therefore, the star polymer photoresist film-forming resin provided in the present application has a relatively uniform and regular four-arm star structure, controllable molecular weight and narrow molecular weight distribution, and has a higher photosensitive group content, which can greatly improve the resolution of the photoresist; it has a lower molecular chain fluid volume, reduces the degree of chain entanglement, and can significantly optimize the roughness; it can be well exposed under 365nm conditions, so that the prepared photoresist composition has broad application prospects in photolithography technology.

[0134] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0135] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions recorded in the aforementioned embodiments may still be modified, or some or all of the technical features therein may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A star polymer photoresist film-forming resin, characterized in that: Its structure is shown in formula (I): in, R1 is selected from one of hydrogen atom and methyl; R2 is selected from one of carbonate, ester and ether; R3 is selected from one of alkyl and alicyclic unit; x, y and z are positive integers, and the sum of the three is the degree of polymerization of the copolymer; The number average molecular weight of the star polymer photoresist film-forming resin is 3000-60000.

2. The star polymer photoresist film-forming resin according to claim 1, characterized in that: The R2 is selected from a group of formula (II)-(VI).

3. The star polymer photoresist film-forming resin according to claim 1, characterized in that: The R3 is selected from a group of formula (VII)-(XIII).

4. A method for preparing the star polymer photoresist film-forming resin according to any one of claims 1 to 3, characterized in that: The preparation method comprises: Styrene, 4-acetoxystyrene, tert-butyl acrylate, RAFT agent and initiator are dissolved in a first solvent for reaction, and then transferred into a second solvent for sedimentation and filtration to obtain a copolymer resin P-1; The copolymer resin P-1 and ammonia water are added into a first solvent for deacetylation, and after evaporation of the solvent, the star polymer photoresist film-forming resin is obtained.

5. The method for preparing the star polymer photoresist film-forming resin according to claim 4, characterized in that: The molar ratio of styrene, 4-acetoxystyrene and tert-butyl acrylate is (10-30): (40-70): (15-30).

6. The method for preparing the star polymer photoresist film-forming resin according to claim 4, characterized in that: The structure of the RAFT agent is shown in formula (XIV): Formula (XIV) The initiator is one or more of azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanenitrile, azoisobutylcyanoformamide, and dimethyl azobisisobutyrate; The molar ratio of the RAFT agent to the initiator is (2-10):

1.

7. The method for preparing the star polymer photoresist film-forming resin according to claim 4, characterized in that: The first solvent is one or more of dichloromethane, chloroform, propylene glycol monomethyl ether acetate, tetrahydrofuran, toluene, acetone, dioxane, dichloroethane, trichloroethane, xylene, and methyl ethyl ketone; The second solvent is n-hexane or methanol.

8. The method for preparing the star polymer photoresist film-forming resin according to claim 4, characterized in that: When styrene, 4-acetoxystyrene, tert-butyl acrylate, RAFT agent and initiator are dissolved in the first solvent for reaction, the reaction temperature is 60-125° C. and the reaction time is 4-36 hours.

9. A photoresist composition, characterized in that: It comprises an organic solvent, a photosensitizer dissolved in the organic solvent, and the star polymer photoresist film-forming resin according to any one of claims 1 to 3; Wherein, the photosensitizer is one of triphenylsulfonium perfluorobutyl sulfonate, triphenylsulfonium trifluoromethyl sulfonate, di(4-tert-butylphenyl)iodonium perfluorobutyl sulfonate, and di(4-tert-butylphenyl)iodonium camphorquinone sulfonate; The mass fraction of the photosensitizer is 1-15%; The mass fraction of the star polymer photoresist film-forming resin is 5-30%.

10. Use of the photoresist composition according to claim 9 in photolithography technology.

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