Photoresist film-forming resin and photoresist composition as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of photoresist, and particularly relates to photoresist film-forming resin, a photoresist composition and a preparation method and application of the photoresist film-forming resin and the photoresist composition. The photoresist film-forming resin comprises a first structural unit derived from a monomer A as shown in a formula (1), a second structural unit derived from a monomer B as shown in a formula (2) and a third structural unit derived from a monomer C as shown in a formula (3). The photoresist film-forming resin provided by the invention comprises a steroid-containing structural unit I, an acid-sensitive group-containing structural unit II and a lactonic ring-containing structural unit III, the photoresist film-forming resin containing the specific structural unit endows the photoresist with significantly improved swelling resistance and enables the photoresist and a substrate to have good adhesion, so that the morphology 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] The invention belongs to the technical field of photoresists, and in particular relates to a photoresist film-forming resin and a photoresist composition, as well as a preparation method and application thereof. Background Art

[0002] With the rapid development of microelectronics technology, integrated circuit manufacturing processes are continuously advancing towards higher precision and smaller sizes. As one of the core processes in semiconductor manufacturing, photolithography technology was primarily based on i-line lithography in its early stages. i-line lithography uses ultraviolet light with a wavelength of 365nm as its light source. Recent technological advances have enabled the use of KrF excimer lasers and even shorter ArF excimer lasers, which have shorter wavelengths than i-line lithography, and have dramatically reduced line widths.

[0003] In photolithography processes using KrF excimer lasers for exposure, novolac or styrene resins are used as photoresist materials. However, because these resins contain aromatic groups, they absorb ArF excimer laser light and cannot be directly applied to ArF lithography. Therefore, in photolithography processes using ArF excimer lasers for exposure, resins without aromatic groups (e.g., resins with alicyclic backbones) have been used instead of resins containing aromatic groups, primarily acrylic resins. The main principle of photolithographic development is as follows: the photoresist composition contains a radiation-sensitive acid generator and an acrylic resin containing (meth)acrylic acid as a monomer unit protected by a protecting group. The protecting group of the monomer unit is dissociated by the acid generated by exposure, becoming a carboxyl group, thereby becoming alkali-soluble, allowing the exposed portion to be removed by development.

[0004] However, the acrylic resins currently used in ArF lithography generally have the problem of 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 photolithographic material, causing pattern swelling problems, resulting in concave or convex patterns, and affecting the morphology and resolution of the formed photolithographic pattern. Summary of the Invention

[0005] The purpose of the present invention is to address the problems of poor adhesion to the substrate and poor swelling resistance of existing acrylic resins used in ArF photolithography, and to provide a photoresist film-forming resin and a photoresist composition and a preparation method thereof. The resin not only enables the photoresist to have good adhesion to the substrate, but also has extremely high swelling resistance during the development process, thereby ensuring good morphology of fine photolithographic patterns and improving resolution.

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

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

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

[0009] In a fourth aspect, the present invention provides a photoresist composition.

[0010] In a fifth aspect, the present invention provides the use of the above-mentioned photoresist film-forming resin and / or photoresist composition in photolithography technology.

[0011] Specifically, the photoresist film-forming resin includes a structural unit 1 derived from a monomer A shown in formula (1), a structural unit 2 derived from a monomer B shown in formula (2), and a structural unit 3 derived from a 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-C3 alkyl group, and R5 is a group containing a lactone ring.

[0016] In a preferred embodiment, 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).

[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 weight average molecular weight of the photoresist film-forming resin is 3000 to 20000 Da, and the polydispersity PDI is 1.2 to 2.8.

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

[0020]

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

[0022]

[0023] The preparation method comprises: subjecting monomer A represented by formula (1), monomer B represented by formula (2) and monomer C represented by formula (3) to polymerization reaction in the presence of an initiator, and the obtained polymerization product is a 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-C3 alkyl group, and R5 is a group containing a 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: temperature of 60-80° C. and 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 monomer A, monomer B, and monomer C is (0.01-0.1):1.

[0032] The photoresist composition comprises the above-mentioned photoresist film-forming resin, a photoacid generator, an organic solvent I and an optional alkaline additive.

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

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

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

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

[0037] Beneficial effects: The key to the present invention lies in the design and synthesis of a photoresist film-forming resin with a specific structure, which includes a structural unit 1 containing a steroid, a structural unit 2 containing an acid-sensitive group, and a structural unit 3 containing a lactone ring. This photoresist film-forming resin containing specific structural units gives the photoresist significantly improved swelling resistance 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 part, improving the resolution, and has broad application prospects. DETAILED DESCRIPTION

[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 understood as limiting the present invention. In addition, unless otherwise specified, all embodiments of the present invention and optional embodiments 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 the present invention includes a structural unit 1 derived from a monomer A shown in formula (1), a structural unit 2 derived from a monomer B shown in formula (2), and a structural unit 3 derived from a 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 group include, but are not limited to, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group. The fluorine-substituted C1-C3 alkyl group means that at least one hydrogen atom in the C1-C3 alkyl group is replaced by a fluorine atom, and specific examples include but are not limited to: -CF3, -CH2CF3, -CF2CF3, -CH2CH2CF3, -CH(CF3)2 or -CF(CF3)2.

[0040]

[0041] The present invention does not particularly limit the distribution of structural units 1, 2, and 3 in the photoresist film-forming resin structure. That is, the structural units 1, 2, and 3 in the photoresist film-forming resin structure provided by the present invention can be distributed in any manner, and can be random copolymerization, alternating copolymerization, block copolymerization, or graft copolymerization, preferably random copolymerization. The terms "1," "2," and "3" in structural units 1, 2, and 3 are merely for distinction and ease of description and have no other special meaning.

[0042] In the present 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 the molar content of structural unit one in the photoresist film-forming resin as 1 mol, 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 therebetween; 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 therebetween. When the molar ratio of structural unit one, structural unit two and structural unit three in the photoresist film-forming resin is controlled within the above-mentioned preferred range, it is more conducive to exerting 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 of the photoresist to the substrate, thereby improving the resolution of the photolithographic pattern and forming a finer pattern.

[0043] In a 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 of the 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 therebetween; the molar content of the structural unit two is preferably 40-60 mol%, such as 40 mol%, 45 mol%, 50 mol%, 55 mol%, 60 mol% or any value therebetween; the molar content of the structural unit three is preferably 30-50 mol%, such as 30 mol%, 35 mol%, 40 mol%, 45 mol%, 50 mol% or any value therebetween.

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

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

[0046]

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

[0048]

[0049] The preparation method of the photoresist film-forming resin provided by the present invention comprises: subjecting monomer A represented by formula (1), monomer B represented by formula (2) and monomer C represented by formula (3) to a polymerization reaction in the presence of an initiator, and the obtained polymerization product is the photoresist film-forming resin.

[0050] In the preparation process of the photoresist film-forming resin, the molar ratio of the monomer A, monomer B and monomer C is preferably 1:(2.5-6):(2-5). Based on the molar amount of monomer A being 1 mol, the molar amount of the 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 therebetween; the molar amount of the 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 therebetween.

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

[0052] In the preparation process of the photoresist film-forming resin, the initiator is any of the existing compounds that can initiate the polymerization reaction of monomer A represented by formula (1), monomer B represented by formula (2) and monomer C represented by formula (3), preferably an azo compound and / or a peroxide, and specific examples thereof include but are not limited to at least one of azobisisobutyronitrile, azobisisoheptonitrile, dibenzoyl peroxide, diisopropylbenzene peroxide, di-tert-butyl peroxide, dibenzoyl peroxide, isopropylbenzene peroxide and tert-butyl peroxide.

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

[0054] In the preparation of the photoresist film-forming resin, the polymerization reaction is preferably carried out in the presence of an organic solvent II. Specific examples of the organic solvent II include, but are not limited to, at least one of 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 comprises the above-mentioned photoresist film-forming resin, a photoacid generator, an organic solvent I and an optional alkaline additive.

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

[0057] In the present invention, the photoacid generator is preferably selected from at least one of iodine salt compounds or sulfonate compounds, and specific examples thereof include but are not limited to: diphenyliodonium trifluoromethanesulfonate, diphenyliodonium camphorsulfonate, diphenyliodonium perfluoro-1-butanesulfonate, diphenyliodonium perfluorooctanesulfonate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, bis(4-tert-butylphenyl)iodonium perfluoro-1-butanesulfonate, bis(4 At least one of: bis(4-tert-butylphenyl)iodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium perfluorooctanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium camphorsulfonate, triphenylsulfonium perfluoro-1-butanesulfonate, triphenylsulfonium perfluorooctanesulfonate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, p-tolyldiphenylsulfonium trifluoromethanesulfonate, p-tolyldiphenylsulfonium perfluorooctanesulfonate, and p-tolyldiphenylsulfonium perfluoro-1-butanesulfonate.

[0058] In the present 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 amyl ketone, and propylene glycol monomethyl ether.

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

[0060] The present invention will be described in detail below through specific examples. The examples of the embodiments are intended to explain the present invention and are not to be construed as limiting the present invention. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this field or the product specifications are used. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be obtained commercially.

[0061] Synthesis example 1

[0062] This synthesis is used to illustrate the synthesis of a monomer A1 containing a steroid structure. The specific process and synthetic reaction route are as follows:

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

[0064] The nuclear magnetic resonance detection results of monomer A1: 13C-NMR (400 MHz, 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 is used to illustrate the synthesis of a monomer A2 containing a steroid structure. The specific process and synthetic reaction route are as follows:

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

[0069] The nuclear magnetic resonance detection results of monomer A2: 13C-NMR (400 MHz, 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 is used to illustrate the synthesis of a monomer A3 containing a steroid structure. The specific process and synthetic reaction route are as follows:

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

[0074] The nuclear magnetic detection results of monomer A3: 13C-NMR (400 MHz, 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 is used to illustrate 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 isomethacrylate (monomer B1) and 89.19 g (0.45 mol) of valerolactone methacrylate (monomer C1) were dissolved in 200 g of tetrahydrofuran, and nitrogen was introduced while stirring for 10 min. The mixture was then heated to 60° C. and stirred for 30 min. 22 g of a tetrahydrofuran solution containing 2 g (0.012 mol) of azobisisobutyronitrile (AIBN) was then added dropwise to the reaction system. After the addition was completed within 30 min, the reaction was refluxed for 24 h and then cooled to room temperature. The resulting 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, a photoresist film-forming resin, designated P1. Its structural units are shown below, with the molar ratio a:b:c of structural unit 1 derived from monomer A1, structural unit 2 derived from monomer B1, and structural unit 3 derived from monomer C1 being approximately 1:4.5:4.5. GPC analysis revealed that polymer P1 had an Mw of 12,200 Da and a PDI of 1.9.

[0079]

[0080] Preparation Example 2

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

[0082] A photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that an equal molar amount of tricyclo[5.2.1.02,6]dec-8-yl methacrylate (monomer B2) was used instead of 1-methyl-1-cyclohexyl methacrylate (monomer B1). All other conditions were the same as those of Preparation Example 1. The resulting solid polymer, a photoresist film-forming resin, was designated P2. The structural units contained in the resin are shown below, with a molar ratio of a:b:c of approximately 1:4.5:4.5 for structural unit 1 derived from monomer A1, structural unit 2 derived from monomer B2, and structural unit 3 derived from monomer C1. GPC analysis revealed that polymer P2 had an Mw of 9630 Da and a PDI of 2.1.

[0083]

[0084] Preparation Example 3

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

[0086] A photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that the same molar amount of monomer A2 (from Synthesis Example 2) was used instead of monomer A1 (from Synthesis Example 1). All other conditions were the same as those of Preparation Example 1. The solid polymer thus prepared was a photoresist film-forming resin, denoted as P3, and contained the structural units shown below. The molar ratio a:b:c of structural unit 1 derived from monomer A2, structural unit 2 derived from monomer B1, and structural unit 3 derived from monomer C1 was approximately 1:4.5:4.5. GPC analysis showed that polymer P3 had an Mw of 14065 Da and a PDI of 2.3.

[0087]

[0088] Preparation Example 4

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

[0090] A photoresist film-forming resin was prepared according to the method of Preparation Example 3, except that the same molar amount of 2-cyclohexyl-2-propanol methacrylate (monomer B3) was used instead of 1-methyl-1-cyclohexyl methacrylate (monomer B1), and the same molar amount of 2-carbonyl-tetrahydrofuran-3-hydroxy-methacrylate (monomer C2) was used instead of methylvalerolactone methacrylate (monomer C1). The remaining conditions were the same as those of Preparation Example 3. The solid polymer thus prepared was a photoresist film-forming resin, denoted as P4, containing the structural units shown below, and the molar ratio a:b:c of structural unit 1 derived from monomer A2, structural unit 2 derived from monomer B3, and structural unit 3 derived from monomer C2 was approximately 1:4.5:4.5. GPC testing showed that polymer P4 had an Mw of 10332 Da and a PDI of 2.0.

[0091]

[0092] Preparation Example 5

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

[0094] A photoresist film-forming resin was prepared according to the method of Preparation Example 3, except that the same molar amount of 2-carboxy-4-bornyl lactone-5-methyl (monomer C3) was used instead of methacrylate valerolactone (monomer C1). The remaining conditions were the same as those of Preparation Example 3. The solid polymer thus prepared was a photoresist film-forming resin, denoted as P5, and contained the structural units shown below. The molar ratio a:b:c of structural unit 1 derived from monomer A2, structural unit 2 derived from monomer B1, and structural unit 3 derived from monomer C3 was approximately 1:4.5:4.5. GPC testing showed that polymer P4 had an Mw of 13270 Da and a PDI of 1.5.

[0095]

[0096] Preparation Example 6

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

[0098] A photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that the same molar amount of monomer A3 (from Synthesis Example 3) was used instead of monomer A1 (from Synthesis Example 1). All other conditions were the same as those of Preparation Example 1. The solid polymer thus prepared was a photoresist film-forming resin, designated P6, and contained the structural units shown below. The molar ratio a:b:c of structural unit 1 derived from monomer A3, structural unit 2 derived from monomer B1, and structural unit 3 derived from monomer C1 was approximately 1:4.5:4.5. GPC analysis revealed that polymer P6 had an Mw of 9108 Da and a PDI of 2.0.

[0099]

[0100] Preparation Example 7

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

[0102] A photoresist film-forming resin was prepared according to the method of Preparation Example 6, except that the same molar amount of 1-adamantyl methacrylate (monomer B4) was used instead of 1-methyl-1-cyclohexyl methacrylate (monomer B1), and the same molar amount of 2-carboxy-4-norbornyl lactone-5-methacrylate (monomer C3) was used instead of methylvalerolactone methacrylate (monomer C1). The remaining conditions were the same as those of Preparation Example 6. The solid polymer thus prepared was a photoresist film-forming resin, denoted as P7, containing the structural units shown below, and the molar ratio a:b:c of structural unit 1 derived from monomer A3, structural unit 2 derived from monomer B4, and structural unit 3 derived from monomer C3 was approximately 1:4.5:4.5. GPC testing showed that the Mw of polymer P7 was 11540 Da and the PDI was 2.1.

[0103]

[0104] Preparation Example 8

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

[0106] A 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 methacrylate (monomer B1) was 0.15 mol, and the amount of valerolactone methacrylate (monomer C1) was 0.15 mol. The remaining conditions were the same as those in Preparation Example 1. The solid polymer thus prepared was a photoresist film-forming resin, denoted as P8, and the molar ratio a:b:c of structural unit 1 derived from monomer A1, structural unit 2 derived from monomer B1, and structural unit 3 derived from monomer C1 was approximately 1:0.21:0.21. GPC testing showed that polymer P8 had an Mw of 9450 Da and a PDI of 1.36.

[0107] Preparation Example 9

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

[0109] A 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 methacrylate (monomer B1) was 0.1 mol, and the amount of valerolactone methacrylate (monomer C1) was 0.8 mol. The remaining conditions were the same as those in Preparation Example 1. The solid polymer thus prepared was a photoresist film-forming resin, denoted as P9, and contained 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 had an Mw of 12562 Da and a PDI of 1.33.

[0110] Preparation Example 10

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

[0112] A 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 methacrylate (monomer B1) was 0.8 mol, and the amount of valerolactone methacrylate (monomer C1) was 0.1 mol. All other conditions were the same as those in Preparation Example 1. The solid polymer thus prepared was a photoresist film-forming resin, denoted as P10, and contained 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 1:8:1. GPC analysis showed that polymer P10 had an Mw of 8645 Da and a PDI of 1.23.

[0113] Comparative Preparation Example 1

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

[0115] A reference photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that an equal molar amount of methacrylic acid was used instead of monomer A1 (from Synthesis Example 1). All other conditions were the same as in Preparation Example 1. The resulting solid polymer, designated as the reference photoresist film-forming resin, was denoted as DP1. GPC analysis revealed that polymer DP1 had an Mw of 13,220 Da and a PDI of 2.2.

[0116] Comparative Preparation Example 2

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

[0118] A reference photoresist film-forming resin was prepared according to the method of Preparation Example 1, except that an equal molar amount of methacrylic acid was used instead of monomer C1. All other conditions were the same as in Preparation Example 1. The resulting solid polymer, designated as the reference photoresist film-forming resin, was denoted as DP2. GPC analysis revealed that polymer DP2 had an Mw of 12,760 Da and a PDI of 2.4.

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

[0120] Preparation of a photoresist composition: Weigh 60 parts by mass of 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 Example Preparation Examples 1 to 2, respectively, and add each of the above-mentioned photoresist film-forming resins and 0.1 parts by mass of triethanolamine (TEA) and 5 parts by mass of triphenylsulfonium trifluoromethanesulfonate (acid generator) to 500 parts by mass of propylene glycol methyl ether acetate (PGMEA). Fix the resulting mixture on a mechanical oscillator and shake it at room temperature for 20 hours to dissolve the components in PGMEA. Then filter the resulting dissolved product through a filter with a pore size of 0.5 μm to obtain a 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 Example 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 applied to a silicon wafer by spin coating. The resist resin film was formed by pre-baking on a hot plate at 110°C for 60 seconds. Half of the silicon wafer was immersed in a 2.38% tetramethoxyammonium hydroxide aqueous solution (alkaline developer) for 120 seconds, and the film thickness of the immersed part and the non-immersed part was tested by atomic force microscopy (AFM).

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

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

[0125] Resolution (the minimum line width of the spatial pattern obtained under the optimal exposure conditions is the resolution): The minimum critical feature size of the obtained photolithographic pattern was observed using an electron microscope. The results are shown in Table 1.

[0126] Adhesion Test: The developed photoresist pattern was observed under a microscope to check for line shifting, deformation, or peeling. The results are shown in Table 1. ◎ indicates good peeling resistance during development (even fine patterns showed little peeling), and ○ indicates no peeling of large patterns (some peeling of fine patterns was observed).

[0127] (3) Etching resistance test: The photoresist compositions obtained in Examples 1 to 10 and Comparative Examples 1 to 2 were respectively applied on a silicon wafer by spin coating at 2000 r / min for 30 s, and the wafer was baked at 100° C. for 90 s to form a film layer. The thickness of the film layer was measured to obtain the initial thickness, which was recorded as L0. The film layer was etched using CF4 gas. The etching conditions were as follows: the processing chamber pressure was 40 Pa, the PF power was 1300 W, the CF4 gas flow rate was 30 mL / min, and the etching time was 30 s. After the etching was completed, the film thickness was measured again to obtain the thickness after etching, which was recorded 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] It can be seen from the results in Table 1 that compared with the reference photoresist film-forming resins obtained in Comparative Preparation Examples 1 and 2, the photoresist film-forming resins provided by Preparation Examples 1 to 10 have a smaller film thickness increment before and after immersion in an organic solvent and have better swelling resistance. Therefore, compared with the reference photoresist compositions obtained in Comparative Examples 1 and 2, the photoresist compositions provided by Examples 1 to 10 of the present invention have better adhesion to the substrate and exhibit higher resolution and etching resistance.

[0131] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A photoresist film-forming resin, characterized in that The photoresist film-forming resin comprises a structural unit 1 derived from a monomer A shown in formula (1), a structural unit 2 derived from a monomer B shown in formula (2), and a structural unit 3 derived from a 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 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 a lactone ring.

2. The photoresist film-forming resin according to claim 1, characterized in that 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); Preferably, based on the total molar amount of structural unit 1, structural unit 2 and structural unit 3 in the photoresist resin, the molar content of structural unit 1 accounts for 10-15 mol%, the molar content of structural unit 2 accounts for 40-60 mol%, and the molar content of structural unit 3 accounts for 30-50 mol%; Preferably, the weight average molecular weight of the photoresist film-forming resin is 3000 to 20000 Da, and the polydispersity PDI is 1.2 to 2.

8.

3. The photoresist film-forming resin according to claim 1, characterized in that The R3 is selected from any one of the following structures: Preferably, the R5 is selected from any one of the following structures:

4. A method for preparing a photoresist film-forming resin, characterized in that: The preparation method comprises: subjecting monomer A represented by formula (1), monomer B represented by formula (2) and monomer C represented by formula (3) to polymerization reaction in the presence of an initiator, and the obtained polymerization product is a photoresist film-forming resin; 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 a lactone ring.

5. The method for preparing the photoresist film-forming resin according to claim 4, wherein: The molar ratio of monomer A, monomer B and monomer C is 1:(2.5-6):(2-5); Preferably, the polymerization reaction conditions include: temperature of 60 to 80° C. and time of 6 to 36 hours.

6. The method for preparing a photoresist film-forming resin according to claim 4, wherein: The initiator is an azo compound and / or a peroxide; Preferably, the molar ratio of the initiator to the sum of monomer A, monomer B, and monomer C is (0.01-0.1):

1.

7. A photoresist film-forming resin prepared by the method according to any one of claims 4 to 6.

8. A photoresist composition, characterized in that The photoresist composition comprises the photoresist film-forming resin according to any one of claims 1 to 3 and 7, a photoacid generator, an organic solvent I, and an optional alkaline additive.

9. The photoresist composition according to claim 8, characterized in that Based on the total mass of the photoresist composition, the content of the photoresist film-forming resin is 1 to 15 wt %, the content of the photoacid generator is 0.5 to 5 wt %, the content of the organic solvent I is 80 to 95 wt %, and the content of the alkaline additive is 0 to 1 wt %; Preferably, the photoacid generator is selected from at least one of iodine salt compounds or sulfonate compounds; Preferably, the organic solvent I is selected from at least one of propylene glycol methyl ether acetate, ethyl lactate, methyl amyl ketone, and propylene glycol monomethyl ether; Preferably, the alkaline additive is selected from at least one of tetra-n-butylammonium hydroxide, tetrabutylammonium acetate, tri-n-octylamine, 2,6-diisopropylaniline, and triethanolamine.

10. Use of the photoresist film-forming resin according to any one of claims 1 to 3 and 7 and / or the photoresist composition according to any one of claims 8 to 9 in photolithography technology.

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