A photoresist film-forming resin and a photoresist composition, and a method for preparing and using the same

Abstract

The application belongs to the technical field of photoresists, and particularly relates to a photoresist film-forming resin, a photoresist composition, and a preparation method and application thereof. The photoresist film-forming resin comprises structural unit one derived from monomer A shown in formula (1), structural unit two derived from monomer B shown in formula (2), and structural unit three derived from monomer C shown in formula (3). The photoresist film-forming resin provided by the application comprises structural unit one containing a steroid, structural unit two containing an acid-sensitive group, and structural unit three containing a lactone ring. The photoresist film-forming resin containing the specific structural units can significantly improve the swelling resistance of the photoresist and make the photoresist have good adhesion to a substrate, so that the appearance of a photoetching pattern, especially the pattern effect of a fine part, can be improved, the resolution is improved, and the application prospect is wide.

Description

Technical Field

[0001] This invention belongs to the field of photoresist technology, specifically relating to a photoresist film-forming resin and a photoresist composition, as well as their preparation method and application. Background Technology

[0002] With the rapid development of microelectronics technology, integrated circuit manufacturing processes are constantly advancing towards higher precision and smaller dimensions. As one of the core processes in semiconductor manufacturing, photolithography, in its early stages, primarily used i-line lithography, which employed ultraviolet light with a wavelength of 365nm as the light source. However, due to recent technological advancements, the use of KrF excimer lasers with shorter wavelengths and ArF excimer lasers with even shorter wavelengths has become possible compared to i-line lithography, resulting in a dramatic increase in linewidth.

[0003] In photolithography using KrF excimer lasers, phenolic varnish-based or styrene-based resins are used as photoresist materials. However, these resins contain aromatic groups, which can absorb ArF excimer laser light, making them unsuitable for direct application in ArF lithography. Therefore, in photolithography using ArF excimer lasers, resins without aromatic groups (e.g., resins with an alicyclic backbone) are used instead of those containing aromatic groups, primarily acrylic resins. The main photolithography and development principle is as follows: the photoresist composition contains a radiation-sensitive acid-generating agent and an acrylic resin containing (meth)acrylic acid as a monomer unit protected by a protected group. The protecting group of this monomer unit is released by the acid generated during exposure, becoming a carboxyl group, thus becoming alkali-soluble, allowing the exposed portion to be removed through development.

[0004] However, acrylic resins currently used in ArF lithography generally have poor adhesion to the substrate. Moreover, with the development of miniaturization, during the development process, the developer can easily penetrate into the interior of the lithographic material, causing pattern swelling, resulting in pattern depressions or protrusions, which affects the morphology and resolution of the formed lithographic pattern. Summary of the Invention

[0005] The purpose of this invention is to address the common problems of poor adhesion to the substrate and poor swelling resistance of existing acrylic resins used in ArF lithography, and to provide a photoresist film-forming resin and a photoresist composition and its preparation method. This not only ensures that the photoresist has good adhesion to the substrate, but also has extremely high swelling resistance during the development process, ensuring good morphology of the micro-lithographic pattern and improving resolution.

[0006] In a first aspect, the present invention provides a photoresist film-forming resin.

[0007] Secondly, the present invention provides a method for preparing a photoresist film-forming resin.

[0008] Thirdly, the present invention provides a photoresist film-forming resin prepared by the above method.

[0009] Fourthly, the present invention provides a photoresist composition.

[0010] Fifthly, the present invention provides the application of the above-mentioned photoresist film-forming resin and / or photoresist composition in photolithography technology.

[0011] Specifically, the photoresist film-forming resin includes structural unit one derived from monomer A shown in formula (1), structural unit two derived from monomer B shown in formula (2), and structural unit three derived from monomer C shown in formula (3):

[0012]

[0013] In formula (1), R1 is a hydrogen atom, a fluorine atom, a C1-C3 alkyl group, or a C1-C3 alkyl group substituted with a fluorine atom;

[0014] In formula (2), R2 is a hydrogen atom or a C1-C3 alkyl group, and R3 is an acid-sensitive group;

[0015] In formula (3), R4 is a hydrogen atom or a C1 to C3 alkyl group, and R5 is a group containing an lactone ring.

[0016] In a preferred embodiment, the molar ratio of structural unit one, structural unit two, and structural unit three in the photoresist film-forming resin is 1:(2.5-6):(2-5).

[0017] In a preferred embodiment, based on the total molar amount of structural unit one, structural unit two, and structural unit three in the photoresist resin, the molar content of structural unit one is 10-15 mol%, the molar content of structural unit two is 40-60 mol%, and the molar content of structural unit three is 30-50 mol%.

[0018] In a preferred embodiment, the photoresist film-forming resin has a weight-average molecular weight of 3000-20000 Da and a polydispersity (PDI) of 1.2-2.8.

[0019] In a preferred embodiment, R3 is selected from any of the following structures:

[0020]

[0021] In a preferred embodiment, R5 is selected from any of the following structures:

[0022]

[0023] The preparation method includes: polymerizing monomer A shown in formula (1), monomer B shown in formula (2) and monomer C shown in formula (3) in the presence of an initiator, and the resulting polymer product is the photoresist film-forming resin.

[0024]

[0025] In formula (1), R1 is a hydrogen atom, a fluorine atom, a C1-C3 alkyl group, or a C1-C3 alkyl group substituted with a fluorine atom;

[0026] In formula (2), R2 is a hydrogen atom or a C1-C3 alkyl group, and R3 is an acid-sensitive group;

[0027] In formula (3), R4 is a hydrogen atom or a C1 to C3 alkyl group, and R5 is a group containing an lactone ring.

[0028] In a preferred embodiment, the molar ratio of monomer A, monomer B and monomer C is 1:(2.5-6):(2-5).

[0029] In a preferred embodiment, the polymerization reaction conditions include a temperature of 60–80°C and a time of 6–12 hours.

[0030] In a preferred embodiment, the initiator is an azo compound and / or a peroxide.

[0031] In a preferred embodiment, the molar ratio of the initiator to the sum of monomers A, B, and C is (0.01 to 0.1):1.

[0032] The photoresist composition includes the above-mentioned photoresist film-forming resin, photoacid generator, organic solvent I, and optional alkaline additives.

[0033] In a preferred embodiment, based on the total mass of the photoresist composition, the content of the photoresist film-forming resin is 1-15 wt%, the content of the photoacid generator is 0.5-5 wt%, the content of organic solvent I is 80-95 wt%, and the content of the alkaline additive is 0-1 wt%.

[0034] In a preferred embodiment, the photoacid generator is selected from at least one of iodide salts or sulfonate salts.

[0035] In a preferred embodiment, the organic solvent I is selected from at least one of propylene glycol methyl ether acetate, ethyl lactate, methyl pentyl ketone, and propylene glycol monomethyl ether.

[0036] In a preferred embodiment, the alkaline additive is selected from at least one of tetrabutylammonium hydroxide, tetrabutylammonium acetate, tri-n-octylamine, 2,6-diisopropylaniline, and triethanolamine.

[0037] Beneficial effects: The key to this invention lies in the design and synthesis of a photoresist film-forming resin with a specific structure, which includes a structural unit containing steroids, a structural unit containing acid-sensitive groups, and a structural unit containing lactone rings. This photoresist film-forming resin with specific structural units imparts significantly improved swelling resistance to the photoresist and enables the photoresist to have good adhesion to the substrate, thereby improving the morphology of the photolithographic pattern, especially the pattern effect of the fine parts, increasing the resolution, and showing broad application prospects. Detailed Implementation

[0038] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Furthermore, unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present invention.

[0039] The photoresist film-forming resin provided by this invention comprises structural unit one derived from monomer A shown in formula (1), structural unit two derived from monomer B shown in formula (2), and structural unit three derived from monomer C shown in formula (3). In formula (1), R1 is a hydrogen atom, a fluorine atom, a C1-C3 alkyl group, or a C1-C3 alkyl group optionally substituted with a fluorine atom. When R1 is preferably a fluorine atom or a C1-C3 alkyl group optionally substituted with a fluorine atom, it is beneficial to further improve the swelling resistance of the photoresist film-forming resin. In formula (2), R2 is a hydrogen atom or a C1-C3 alkyl group, and R3 is an acid-sensitive group. In formula (3), R4 is a hydrogen atom or a C1-C3 alkyl group, and R5 is a group containing a lactone ring. Specific examples of the C1-C3 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, or isopropyl. The fluorine-substituted C1-C3 alkyl group refers to the alkyl group in which at least one hydrogen atom is replaced by a fluorine atom. Specific examples include, but are not limited to: -CF3, -CH2CF3, -CF2CF3, -CH2CH2CF3, -CH(CF3)2 or -CF(CF3)2.

[0040]

[0041] This invention does not impose any particular limitation on the distribution of structural unit one, structural unit two, and structural unit three in the photoresist film-forming resin structure. That is, structural unit one, structural unit two, and structural unit three in the photoresist film-forming resin structure provided in this invention can be distributed in any manner, including random copolymerization, alternating copolymerization, block copolymerization, or graft copolymerization, preferably random copolymerization. The terms "one," "two," and "three" in structural unit one, structural unit two, and structural unit three are merely for distinguishing purposes and have no other special meaning.

[0042] In this invention, the molar ratio of structural unit one, structural unit two, and structural unit three in the photoresist film-forming resin is preferably 1:(2.5-6):(2-5). Taking 1 mol of structural unit one in the photoresist film-forming resin as a unit, the molar content of structural unit two is preferably 3-6 mol, such as 2.5 mol, 3 mol, 3.5 mol, 4 mol, 4.5 mol, 5 mol, 5.5 mol, 6 mol, or any value between them; the molar content of structural unit three is preferably 2-5 mol, such as 2 mol, 2.5 mol, 3 mol, 3.5 mol, 4 mol, 4.5 mol, 5 mol, or any value between them. Controlling the molar ratio of structural unit one, structural unit two, and structural unit three in the photoresist film-forming resin within the above-mentioned preferred range is more conducive to leveraging the synergistic effect of structural unit one, structural unit two, and structural unit three, improving the swelling resistance of the photoresist film-forming resin, and improving the adhesion between the photoresist and the substrate, thereby improving the resolution of the photolithographic pattern and forming a finer pattern.

[0043] In one specific embodiment, based on the total molar amount of structural unit one, structural unit two, and structural unit three in the photoresist resin, the molar content percentage of structural unit one is preferably 10-15 mol%, such as 10 mol%, 11 mol%, 12 mol%, 13 mol%, 14 mol%, 15 mol%, or any value between them; the molar content percentage of structural unit two is preferably 40-60 mol%, such as 40 mol%, 45 mol%, 50 mol%, 55 mol%, 60 mol%, or any value between them; and the molar content percentage of structural unit three is preferably 30-50 mol%, such as 30 mol%, 35 mol%, 40 mol%, 45 mol%, 50 mol%, or any value between them.

[0044] In this invention, the weight-average molecular weight (Mw) of the photoresist film-forming resin is preferably 3000–20000 Da, such as 3000 Da, 5000 Da, 8000 Da, 10000 Da, 15000 Da, 20000 Da, or any value between them. The polydispersity (PDI) of the photoresist film-forming resin is preferably 1.2–2.8, such as 1.2, 1.5, 1.8, 2.0, 2.2, 2.5, 2.8, or any value between them.

[0045] In this invention, R3 is preferably selected from any of the following structures:

[0046]

[0047] In this invention, R5 is preferably selected from any of the following structures:

[0048]

[0049] The preparation method of photoresist film-forming resin provided by the present invention includes: polymerizing monomer A shown in formula (1), monomer B shown in formula (2) and monomer C shown in formula (3) in the presence of an initiator, and the resulting polymer product is the photoresist film-forming resin.

[0050] In the preparation process of the photoresist film-forming resin, the molar ratio of monomer A, monomer B, and monomer C is preferably 1:(2.5-6):(2-5). Taking 1 mol of monomer A as the molar amount, the molar amount of monomer B is preferably 3-6 mol, such as 2.5 mol, 3 mol, 3.5 mol, 4 mol, 4.5 mol, 5 mol, 5.5 mol, 6 mol, or any value between them; the molar amount of monomer C is preferably 2-5 mol, such as 2 mol, 2.5 mol, 3 mol, 3.5 mol, 4 mol, 4.5 mol, 5 mol, or any value between them.

[0051] In the preparation of the photoresist film-forming resin, the preferred conditions for the polymerization reaction include: a temperature of 60–80°C, such as 60°C, 65°C, 70°C, 75°C, 80°C or any value between them; and a time of 6–36 h, such as 6 h, 8 h, 10 h, 12 h, 18 h, 24 h, 30 h, 36 h or any value between them.

[0052] In the preparation of photoresist film-forming resin, the initiator is any existing compound capable of initiating the polymerization reaction of monomer A shown in formula (1), monomer B shown in formula (2), and monomer C shown in formula (3), preferably an azo compound and / or peroxide, specific examples of which include, but are not limited to, at least one of azobisisobutyronitrile, azobisisoheptane, benzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, benzoyl peroxide, cumyl peroxide, and tert-butyl peroxide.

[0053] In the preparation process of photoresist film-forming resin, the molar ratio of the initiator to the sum of monomers A, B, and C is preferably (0.01 to 0.1):1, such as 0.01:1, 0.02:1, 0.05:1, 0.08:1, 0.1:1, or any value between them.

[0054] In the preparation of the photoresist film-forming resin, the polymerization reaction is preferably carried out in the presence of organic solvent II. Specific examples of organic solvent II include, but are not limited to, at least one of the following: tetrahydrofuran, dioxane, acetone, acetonitrile, cyclohexanone, benzene, toluene, chlorobenzene, xylene, dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, ethyl acetate, butyl acetate, N,N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and dimethyl sulfoxide.

[0055] The photoresist composition provided by the present invention includes the above-mentioned photoresist film-forming resin, photoacid generator, organic solvent I, and optional alkaline additives.

[0056] In this invention, based on the total mass of the photoresist composition, the content of the photoresist film-forming resin is preferably 1-15 wt%, such as 1 wt%, 2 wt%, 5 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, or any value between them; the content of the photoacid generator is preferably 0.5-5 wt%, such as 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, or any value between them; the content of the organic solvent I is preferably 80-95 wt%, such as 80 wt%, 82 wt%, 85 wt%, 88 wt%, 90 wt%, 92 wt%, 95 wt%, or any value between them; the content of the alkaline additive is preferably 0-1 wt%, such as 0 wt%, 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.2 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, or any value between them.

[0057] In this invention, the photoacid generator is preferably at least one of iodide salt compounds or sulfonate compounds, and specific examples include, but are not limited to: diphenyliodonium trifluoromethanesulfonate, diphenyliodonium camphor sulfonate, diphenyliodonium perfluoro-1-butanesulfonate, diphenyliodonium perfluorooctane sulfonate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, bis(4-tert-butylphenyl)iodonium perfluoro-1-butane ... At least one of the following: (-tert-butylphenyl)iodonium camphor sulfonate, bis(4-tert-butylphenyl)iodonium perfluorooctane sulfonate, triphenylsulfonium trifluoromethane sulfonate, triphenylsulfonium camphor sulfonate, triphenylsulfonium perfluoro-1-butyl sulfonate, triphenylsulfonium perfluorooctane sulfonate, 4-methoxyphenylphenyliodonium trifluoromethane sulfonate, p-tolyldiphenylsulfonium trifluoromethane sulfonate, p-tolyldiphenylsulfonium perfluorooctane sulfonate, and p-tolyldiphenylsulfonium perfluoro-1-butane sulfonate.

[0058] In this invention, specific examples of the organic solvent I include, but are not limited to, at least one of propylene glycol methyl ether acetate, ethyl lactate, methyl pentyl ketone, and propylene glycol monomethyl ether.

[0059] In this invention, specific examples of the alkaline additive include, but are not limited to, at least one of tetrabutylammonium hydroxide, tetrabutylammonium acetate, tri-n-octylamine, 2,6-diisopropylaniline, and triethanolamine.

[0060] The present invention will be described in detail below through specific embodiments. These embodiments are intended to explain the invention and should not be construed as limiting it. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0061] Synthesis example 1

[0062] This synthesis illustrates the synthesis of a monomer A1 containing a steroid structure. The specific process and synthetic reaction route are shown below:

[0063] Under nitrogen protection, 29.05 g (100 mmol) of androstenedione and 200 mL of anhydrous dichloromethane were added to a three-necked flask and stirred to dissolve. Then, 12.14 g (120 mmol) of triethylamine and 11.5 g (110 mmol) of methacryloyl chloride were added and the mixture was stirred at room temperature for 5 h. The resulting solid-liquid system was filtered and the filtrate was collected. The filtrate was then separated into products by column chromatography to obtain monomer A1.

[0064] NMR results for monomer A1: 13C-NMR (400MHz, DMSO) 220.0 (1C), 48.1 (1C), 51.1 (1C), 35.7 (1C), 21.7 (1C), 74.3 (1C), 36.5 (1C), 31.3 (1C), 35.7 (1C), 53.4 (1C), 44.0 (1C), 34.7 (1C), 27.4 (1C), 30.8 (1C), 20.4 (1C), 37.7 (1C), 27.0 (1C), 167.2 (1C), 14.1 (1C), 12.2 (1C), 136.0 (1C), 125.2 (1C), 17.9 (1C).

[0065]

[0066] Synthesis example 2

[0067] This synthesis illustrates the synthesis of a monomer A2 containing a steroid structure. The specific process and synthetic reaction route are shown below:

[0068] Under nitrogen protection, 29.05 g (100 mmol) of androsterone and 200 mL of anhydrous dichloromethane were added to a three-necked flask and stirred to dissolve. Then, 12.14 g (120 mmol) of triethylamine and 11.94 g (110 mmol) of 2-fluoroacryloyl chloride were added and the mixture was stirred at room temperature for 5 h. The resulting solid-liquid system was filtered and the filtrate was collected. The filtrate was then separated into products by column chromatography to obtain monomer A2.

[0069] NMR results for monomer A2: 13C-NMR (400MHz, DMSO) 220.0 (1C), 48.1 (1C), 51.1 (1C), 35.7 (2C), 21.7 (1C), 74.3 (1C), 36.5 (1C), 31.3 (1C), 53.4 (1C), 44.0 (1C), 34.7 (1C), 27.4 (1C), 30.8 (1C), 20.4 (1C), 37.7 (1C), 27.0 (1C), 160.5 (1C), 14.1 (1C), 12.2 (1C), 156.0 (1C), 96.0 (1C).

[0070]

[0071] Synthesis example 3

[0072] This synthesis illustrates the synthesis of a monomer A3 containing a steroid structure. The specific process and synthetic reaction route are shown below:

[0073] Under nitrogen protection, 29.05 g (100 mmol) of androsterone and 200 ml of anhydrous dichloromethane were added to a three-necked flask and stirred to dissolve. Then, 12.14 g (120 mmol) of triethylamine and 17.43 g (110 mmol) of 2-(trifluoromethyl)-2-acryloyl chloride were added and the mixture was stirred at room temperature for 5 h. The resulting solid-liquid system was filtered and the filtrate was collected. The product was separated by column chromatography to obtain monomer A3.

[0074] NMR results for monomer A3: 13C-NMR (400MHz, DMSO) 220.0 (1C), 48.1 (1C), 51.1 (1C), 35.7 (2C), 21.7 (1C), 74.3 (1C), 36.5 (1C), 31.3 (1C), 53.4 (1C), 44.0 (1C), 34.7 (1C), 27.4 (1C), 30.8 (1C), 20.4 (1C), 37.7 (1C), 27.0 (1C), 125.6 (1C), 167.2 (1C), 14.1 (1C), 12.2 (1C), 138.0 (1C), 125.2 (1C).

[0075]

[0076] Preparation Example 1

[0077] This preparation example illustrates the preparation of a photoresist film-forming resin P1, and the specific process is as follows:

[0078] 35.85 g (0.1 mol) of monomer A1 (from Synthesis Example 1), 82.02 g (0.45 mol) of 1-methyl-1-cyclohexyl isobutylene ester (monomer B1) and 89.19 g (0.45 mol) of mevalonyl methacrylate (monomer C1) were dissolved in 200 g of tetrahydrofuran. Nitrogen gas was introduced while stirring for 10 min. The mixture was then heated to 60 °C and stirred for another 30 min. 22 g of tetrahydrofuran solution containing 2 g (0.012 mol) of azobisisobutyronitrile (AIBN) was added dropwise to the reaction system. After the addition was completed within 30 min, the mixture was refluxed for 24 h and then cooled to room temperature. The obtained product system was extracted three times with heptane to obtain a polymer solution, which was then precipitated in water. The precipitate was vacuum dried to obtain a solid polymer, which is the photoresist film-forming resin, denoted as P1. Its structural units are shown below, and the molar ratio a:b:c of structural unit one derived from monomer A1, structural unit two derived from monomer B1, and structural unit three derived from monomer C1 is approximately 1:4.5:4.5. GPC testing showed that polymer P1 has a Mw of 12200 Da and a PDI of 1.9.

[0079]

[0080] Preparation Example 2

[0081] This preparation example illustrates the preparation of a photoresist film-forming resin P2, and the specific process is as follows:

[0082] The photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that the same molar amount of tricyclo[5.2.1.02,6]dec-8-yl methacrylate (monomer B2) was used instead of 1-methyl-1-cyclohexyl isobutylene ester (monomer B1). All other conditions were the same as in Preparation Example 1. The resulting solid polymer is the photoresist film-forming resin, denoted as P2. Its structural units are shown below, and the molar ratio a:b:c of structural unit one derived from monomer A1, structural unit two derived from monomer B2, and structural unit three derived from monomer C1 is approximately 1:4.5:4.5. GPC testing showed that polymer P2 has a Mw of 9630 Da and a PDI of 2.1.

[0083]

[0084] Preparation Example 3

[0085] This preparation example illustrates the preparation of a photoresist film-forming resin P6, and the specific process is as follows:

[0086] The photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that monomer A2 (from Synthesis Example 2) was used instead of monomer A1 (from Synthesis Example 1) in the same molar amount. All other conditions were the same as in Preparation Example 1. The resulting solid polymer is the photoresist film-forming resin, denoted as P3. Its structural units are shown below, and the molar ratio a:b:c of structural unit one derived from monomer A2, structural unit two derived from monomer B1, and structural unit three derived from monomer C1 is approximately 1:4.5:4.5. GPC testing showed that polymer P3 has a Mw of 14065 Da and a PDI of 2.3.

[0087]

[0088] Preparation Example 4

[0089] This preparation example illustrates the preparation of a photoresist film-forming resin P4, and the specific process is as follows:

[0090] The photoresist film-forming resin was prepared according to the method of Preparation Example 3, except that 2-cyclohexyl-2-propanol methacrylic acid (monomer B3) was used instead of 1-methyl-1-cyclohexyl isobutylene ester (monomer B1) in the same molar amount, and 2-carbonyl-tetrahydrofuran-3-hydroxy-methacrylate (monomer C2) was used instead of mevalonolactone methacrylate (monomer C1). All other conditions were the same as in Preparation Example 3. The resulting solid polymer is the photoresist film-forming resin, denoted as P4. Its structural units are shown below, and the molar ratio a:b:c of structural unit one derived from monomer A2, structural unit two derived from monomer B3, and structural unit three derived from monomer C2 is approximately 1:4.5:4.5. GPC testing showed that polymer P4 has a Mw of 10332 Da and a PDI of 2.0.

[0091]

[0092] Preparation Example 5

[0093] This preparation example illustrates the preparation of a photoresist film-forming resin P5, and the specific process is as follows:

[0094] The photoresist film-forming resin was prepared according to the method of Preparation Example 3, except that the same molar amount of 2-carboxy-4-norbornolactone-5-methyl (monomer C3) was used instead of mevalonolactone methacrylate (monomer C1). All other conditions were the same as in Preparation Example 3. The resulting solid polymer is the photoresist film-forming resin, denoted as P5. Its structural units are shown below, and the molar ratio a:b:c of structural unit one derived from monomer A2, structural unit two derived from monomer B1, and structural unit three derived from monomer C3 is approximately 1:4.5:4.5. GPC testing showed that polymer P4 has a Mw of 13270 Da and a PDI of 1.5.

[0095]

[0096] Preparation Example 6

[0097] This preparation example illustrates the preparation of a photoresist film-forming resin P6, and the specific process is as follows:

[0098] The photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that monomer A3 (from Synthesis Example 3) was used instead of monomer A1 (from Synthesis Example 1) in the same molar amount. All other conditions were the same as in Preparation Example 1. The resulting solid polymer is the photoresist film-forming resin, denoted as P6. Its structural units are shown below, and the molar ratio a:b:c of structural unit one derived from monomer A3, structural unit two derived from monomer B1, and structural unit three derived from monomer C1 is approximately 1:4.5:4.5. GPC testing showed that polymer P6 has a Mw of 9108 Da and a PDI of 2.0.

[0099]

[0100] Preparation Example 7

[0101] This preparation example illustrates the preparation of a photoresist film-forming resin P7, and the specific process is as follows:

[0102] The photoresist film-forming resin was prepared according to the method of Preparation Example 6, except that 1-adamantyl methacrylate (monomer B4) was used instead of 1-methyl-1-cyclohexyl isobutylene acrylate (monomer B1) in the same molar amount, and 2-carboxy-4-norbornolactone-5-methacrylate (monomer C3) was used instead of mevalonolactone methacrylate (monomer C1). All other conditions were the same as in Preparation Example 6. The resulting solid polymer is the photoresist film-forming resin, denoted as P7. Its structural units are shown below, and the molar ratio a:b:c of structural unit one derived from monomer A3, structural unit two derived from monomer B4, and structural unit three derived from monomer C3 is approximately 1:4.5:4.5. GPC testing showed that polymer P7 has a Mw of 11540 Da and a PDI of 2.1.

[0103]

[0104] Preparation Example 8

[0105] This preparation example illustrates the preparation of a photoresist film-forming resin P8, and the specific process is as follows:

[0106] The photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that the amount of monomer A1 (from Synthesis Example 1) was 0.7 mol, the amount of 1-methyl-1-cyclohexyl isobutylene ester (monomer B1) was 0.15 mol, and the amount of mevalonolactone methacrylate (monomer C1) was 0.15 mol. All other conditions were the same as in Preparation Example 1. The resulting solid polymer is the photoresist film-forming resin, denoted as P8. The molar ratio (a:b:c) of structural unit I derived from monomer A1, structural unit II derived from monomer B1, and structural unit III derived from monomer C1 is approximately 1:0.21:0.21. GPC testing showed that polymer P8 has a Mw of 9450 Da and a PDI of 1.36.

[0107] Preparation Example 9

[0108] This preparation example illustrates the preparation of a photoresist film-forming resin P9, and the specific process is as follows:

[0109] The photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that the amount of monomer A1 (from Synthesis Example 1) was 0.1 mol, the amount of 1-methyl-1-cyclohexyl isobutylene ester (monomer B1) was 0.1 mol, and the amount of mevalonolactone methacrylate (monomer C1) was 0.8 mol. All other conditions were the same as in Preparation Example 1. The resulting solid polymer is the photoresist film-forming resin, denoted as P9. It contains structural unit 1 derived from monomer A1, structural unit 2 derived from monomer B1, and structural unit 3 derived from monomer C1 in a molar ratio of approximately a:b:c of 1:1:8. GPC testing showed that polymer P9 has a Mw of 12562 Da and a PDI of 1.33.

[0110] Preparation Example 10

[0111] This preparation example illustrates the preparation of a photoresist film-forming resin P10, and the specific process is as follows:

[0112] The photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that the amount of monomer A1 (from Synthesis Example 1) was 0.1 mol, the amount of 1-methyl-1-cyclohexyl isobutylene ester (monomer B1) was 0.8 mol, and the amount of mevalonolactone methacrylate (monomer C1) was 0.1 mol. All other conditions were the same as in Preparation Example 1. The resulting solid polymer, denoted as P10, is the photoresist film-forming resin. It contains structural unit 1 derived from monomer A1, structural unit 2 derived from monomer B1, and structural unit 3 derived from monomer C1 in a molar ratio of approximately a:b:c 1:8:1. GPC testing showed that polymer P10 has a Mw of 8645 Da and a PDI of 1.23.

[0113] Comparative Preparation Example 1

[0114] This comparative preparation example illustrates the preparation of a reference photoresist film-forming resin DP1, and the specific process is as follows:

[0115] The reference photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that the same molar amount of methacrylic acid was used instead of monomer A1 (from Synthesis Example 1), and all other conditions were the same as in Preparation Example 1. The resulting solid polymer is the reference photoresist film-forming resin, denoted as DP1. GPC testing showed that polymer DP1 has a Mw of 13220 Da and a PDI of 2.2.

[0116] Comparative Preparation Example 2

[0117] This comparative preparation example illustrates the preparation of a reference photoresist film-forming resin DP2, and the specific process is as follows:

[0118] The reference photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that the same molar amount of methacrylic acid was used instead of monomer C1, and all other conditions were the same as in Preparation Example 1. The resulting solid polymer is the reference photoresist film-forming resin, denoted as DP2. GPC testing showed that polymer DP2 has a Mw of 12760 Da and a PDI of 2.4.

[0119] Examples 1-10 and Comparative Examples 1-2

[0120] Preparation of photoresist composition: 60 parts by mass of photoresist film-forming resins P1 to P10 obtained in Preparation Examples 1 to 10 and reference photoresist film-forming resins DP1 and DP2 obtained in Comparative Preparation Examples 1 to 2 were weighed respectively. The above photoresist film-forming resins were added to 500 parts by mass of propylene glycol methyl ether acetate (PGMEA) along with 0.1 parts by mass of triethanolamine (TEA) and 5 parts by mass of triphenylthiotrifluoromethanesulfonate (acid generator). The resulting mixture was fixed on a mechanical oscillator and shaken at room temperature for 20 hours to dissolve each component in PGMEA. The resulting dissolved product was then filtered through a filter with a pore size of 0.5 μm to obtain the photoresist composition solution.

[0121] Test case

[0122] (1) Swelling Resistance Test: The photoresist film-forming resins P1 to P10 obtained in Preparation Examples 1 to 10 and the reference photoresist film-forming resins DP1 and DP2 obtained in Comparative Preparation Examples 1 to 2 were dissolved in propylene glycol methyl ether acetate to prepare a resin solution with a solid content of 10%. The above resin solution was coated onto a silicon wafer by spin coating. The resist resin film was formed by pre-baking on a hot plate at 110°C for 60 s. After immersing half of the silicon wafer in a 2.38% tetramethoxyammonium hydroxide aqueous solution (alkaline developer) for 120 s, the film thickness of the immersed and unimmersed portions was measured by atomic force microscopy (AFM).

[0123] To evaluate the swelling resistance, the film thickness of the impregnated part was set as "M (nm)" and the film thickness of the non-impregnated part was set as "N (nm)". The film thickness increase rate Y (%) before and after impregnation with alkaline developer was calculated using the formula: Y (%) = (MN) / N × 100%. The results are shown in Table 1.

[0124] (2) Resolution and adhesion to substrate test: The photoresist compositions obtained in Examples 1-10 and Comparative Examples 1-2 were spin-coated onto silicon wafers at 2000 r / min for 30 s, pre-baked at 110°C for 60 s, and the coated samples were exposed to the ArF machine through a photomask. They were then baked at 100°C for 60 s and then developed with 2.38% tetramethylammonium hydroxide (TMAH) developer for 60 s to obtain the corresponding photolithographic patterns.

[0125] Resolution (the minimum linewidth of the spatial pattern obtained under optimal exposure conditions is the resolution): the minimum critical feature size of the lithographic pattern obtained by observation with an electron microscope. The results are shown in Table 1.

[0126] Adhesion test: The developed photolithographic pattern was observed under a microscope to check for any displacement, deformation, or detachment of the lines. The results are shown in Table 1. Wherein: ◎ indicates good resistance to peeling during development (even fine patterns hardly peel off), ○ indicates no large pattern peeling observed (some fine patterns peeled off).

[0127] (3) Etching Resistance Test: The photoresist compositions obtained in Examples 1-10 and Comparative Examples 1-2 were spin-coated onto silicon wafers at 2000 r / min for 30 s. The wafers were then baked at 100°C for 90 s to form a film. The thickness of the film was measured to obtain the initial thickness, denoted as L0. The film was etched using CF4 gas under the following conditions: processing chamber pressure of 40 Pa, PF power of 1300 W, CF4 gas flow rate of 30 mL / min, and etching time of 30 s. After etching, the film thickness was measured again to obtain the post-etched thickness, denoted as L1. The etching rate was calculated using the formula: Etching Rate = (L0 - L1) / Etching Time. The results are shown in Table 1.

[0128] Table 1

[0129]

[0130] As shown in Table 1, compared with the reference photoresist film-forming resins obtained in Comparative Preparation Example 1 and Comparative Preparation Example 2, the photoresist film-forming resins provided in Preparation Examples 1 to 10 have smaller film thickness increments before and after impregnation with organic solvents, and have better swelling resistance. Therefore, compared with the reference photoresist compositions obtained in Comparative Examples 1 and 2, the photoresist compositions provided in Examples 1 to 10 of the present invention have better adhesion to the substrate and exhibit higher resolution and etching resistance.

[0131] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A photoresist film-forming resin, characterized in that, The photoresist film-forming resin includes structural unit one derived from monomer A shown in formula (1), structural unit two derived from monomer B shown in formula (2), and structural unit three derived from monomer C shown in formula (3): Equation (1), Equation (2), Equation (3), In formula (1), R1 is a hydrogen atom, a fluorine atom, a C1~C3 alkyl group, or a C1~C3 alkyl group substituted with a fluorine atom; In formula (2), R2 is a hydrogen atom or a C1~C3 alkyl group, and R3 is an acid-sensitive group; In formula (3), R4 is a hydrogen atom or a C1~C3 alkyl group, and R5 is a group containing an lactone ring; The molar ratio of structural unit 1, structural unit 2 and structural unit 3 in the photoresist film-forming resin is 1:(2.5~6):(2~5).

2. The photoresist film-forming resin according to claim 1, characterized in that, Based on the total molar amount of structural unit 1, structural unit 2 and structural unit 3 in the photoresist film-forming resin, the molar content of structural unit 1 is 10~15mol%, the molar content of structural unit 2 is 40~60mol%, and the molar content of structural unit 3 is 30~50mol.

3. The photoresist film-forming resin according to claim 1, characterized in that, The photoresist film-forming resin has a weight-average molecular weight of 3000~20000 Da and a polydispersity (PDI) of 1.2~2.

8.

4. The photoresist film-forming resin according to claim 1, characterized in that, R3 is selected from any of the following structures: 。 5. The photoresist film-forming resin according to claim 1, characterized in that, R5 is selected from any of the following structures: 。 6. A method for preparing a photoresist film-forming resin, characterized in that, The preparation method includes: polymerizing monomer A (1), monomer B (2), and monomer C (3) in the presence of an initiator, and the resulting polymer product is the photoresist film-forming resin; the molar ratio of monomer A, monomer B, and monomer C is 1:(2.5~6):(2~5); Equation (1), Equation (2), Equation (3), In formula (1), R1 is a hydrogen atom, a fluorine atom, a C1~C3 alkyl group, or a C1~C3 alkyl group substituted with a fluorine atom; In formula (2), R2 is a hydrogen atom or a C1~C3 alkyl group, and R3 is an acid-sensitive group; In formula (3), R4 is a hydrogen atom or a C1~C3 alkyl group, and R5 is a group containing an lactone ring.

7. The method for preparing photoresist film-forming resin according to claim 6, characterized in that, The conditions for the polymerization reaction include: a temperature of 60~80℃ and a time of 6~36h.

8. The method for preparing photoresist film-forming resin according to claim 6, characterized in that, The initiator is an azo compound and / or a peroxide.

9. The method for preparing photoresist film-forming resin according to claim 6, characterized in that, The molar ratio of the initiator to the sum of monomers A, B, and C is (0.01~0.1):

1.

10. The photoresist film-forming resin prepared by the method according to any one of claims 6 to 9.

11. A photoresist composition, characterized in that, The photoresist composition comprises the photoresist film-forming resin according to any one of claims 1 to 5 and 10, a photoacid generator, organic solvent I, and optional alkaline additives.

12. The photoresist composition according to claim 11, characterized in that, Based on the total mass of the photoresist composition, the content of the photoresist film-forming resin is 1~15wt%, the content of the photoacid generator is 0.5~5wt%, the content of organic solvent I is 80~95wt%, and the content of the alkaline additive is 0~1wt%.

13. The photoresist composition according to claim 11, characterized in that, The photoacid generator is selected from at least one of iodide salt compounds or sulfonate compounds.

14. The photoresist composition according to claim 11, characterized in that, The organic solvent I is selected from at least one of propylene glycol methyl ether acetate, ethyl lactate, methyl pentyl ketone, and propylene glycol monomethyl ether.

15. The photoresist composition according to claim 11, characterized in that, The alkaline additive is selected from at least one of tetrabutylammonium hydroxide, tetrabutylammonium acetate, tri-n-octylamine, 2,6-diisopropylaniline, and triethanolamine.

16. The use of the photoresist film-forming resin according to any one of claims 1 to 5 and 10 and / or the photoresist composition according to any one of claims 11 to 15 in photolithography.

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