Negative photoresist composition and patterning method

Abstract

The invention discloses a negative photoresist composition and a patterning method, and belongs to the technical field of photoetching. The invention provides a negative photoresist composition. The negative photoresist composition comprises 10-30 parts of branched-chain acrylic resin A, 10-20 parts of branched-chain acrylic resin B, 1-5 parts of a photoacid generator and 49-75 parts of an organic solvent. According to the photoresist composition provided by the invention, the addition of a small-molecule reactive diluent or a cross-linking agent is avoided, and the problem of insufficient thermal stability of the negative photoresist due to excessive small-molecule additives is solved. On the basis, the photoresist composition provided by the invention is used as a patterned photoresist material, and has good adhesion performance and resolution.

Description

Technical Field

[0001] The present invention belongs to the field of lithography technology and relates to a negative photoresist composition and a patterning method. Background Art

[0002] Photoresist is a core material in precision microfabrication fields such as semiconductor manufacturing, display panels, and printed circuit boards (PCBs). Its performance directly affects key indicators such as chip circuit structure and display panel resolution. In semiconductor manufacturing, through steps such as exposure and development, the circuit pattern on the mask plate is transferred to the surface of the silicon wafer, laying the foundation for subsequent processes such as etching and doping. Photoresists are classified into positive and negative types according to the chemical reaction characteristics after light exposure. According to their development principles, they can be divided into positive photoresists and negative photoresists. For positive photoresists, the exposed areas are dissolved, and the unexposed parts are retained, which is suitable for high-resolution requirements. The core components of negative photoresists include photosensitizers and resins, etc. After exposure, the photosensitizer absorbs light energy to initiate a photochemical reaction (such as a crosslinking reaction) to form a high-molecular crosslinked polymer that is insoluble in the developer; the unexposed areas are dissolved by the developer due to their higher solubility, and finally a pattern opposite to the mask plate is formed.

[0003] Negative photoresists have excellent contrast, but are prone to edge swelling, deformation, or peeling due to the penetration of the developer, resulting in a relatively high line width roughness, limited resolution, and pattern deformation easily caused by the penetration of the developer, affecting the yield. Currently, the patterning negative photoresists on the market rely on traditional resin systems (such as polyisoprene), and the excessive amount of small molecule additives therein leads to insufficient thermal stability. Therefore, it is an urgent problem for those skilled in the art to develop a negative photoresist material that meets the patterning process conditions and has good adhesion performance and resolution. Summary of the Invention

[0004] Currently, the resin system of the negative photoresist composition used for patterning is single, and small molecule monomers are added as active diluents or crosslinking agents. The disadvantages are that the content of small molecule additives is too high, the thermal stability is poor during the process, and the pattern edge roughness is relatively high, and it is prone to deformation or peeling. To solve this problem, the present invention provides a negative photoresist composition and a patterning method, which avoid adding small molecule active diluents or crosslinking agents and improve the thermal stability of the negative photoresist composition.

[0005] In the first aspect, the present invention provides a negative photoresist composition, comprising: branched acrylic resin A, branched acrylic resin B, photoacid generator, and solvent; The branched acrylic resin A is prepared by a polymerization reaction of epoxy acrylate monomer, long-chain acrylate monomer, styrene monomer, and hydroxyacrylate monomer; The branched acrylic resin B is prepared by polymerizing an epoxy acrylate monomer, a diacrylate monomer, and a styrene monomer; The photoacid generator is an iodonium salt and / or a sulfonium salt; The solvent is selected from one or more of dichloromethane, chloroform, tetrahydrofuran, benzene, toluene, butyrolactone, propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, cyclopentanone, butyl acetate, methyl isobutyl ketone, 2-pentanone, 4-methyl-2-pentanone, cyclohexanone, 2-heptanone, γ-butyrolactone, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, and N,N-dimethylformamide.

[0006] Furthermore, in the negative photoresist composition provided by the present invention, by mass, the photoresist composition includes: 10 to 30 parts of branched acrylic resin A, 10 to 20 parts of branched acrylic resin B, 1 to 5 parts of photoacid generator, and 49 to 75 parts of organic solvent.

[0007] Furthermore, in the negative photoresist composition provided by the present invention, the epoxy acrylate monomer in the branched acrylic resin A is selected from one or more of epoxy methacrylate, glycidyl acrylate, tetrahydrofurfuryl methacrylate, glycidyl 4-hydroxybutyl acrylate, and (3,4-epoxycyclohexyl)methyl acrylate; The long-chain acrylate monomer in the branched acrylic resin A is selected from one or more of ethyl acrylate, butyl acrylate, pentyl acrylate, ethyl methacrylate, butyl methacrylate, lauryl acrylate, lauryl methacrylate, 3,5,5-trimethylhexyl acrylate, diethylene glycol butyl ether methacrylate, hexyl methacrylate, and n-octyl acrylate; The styrene monomer in the branched acrylic resin A is selected from the following general formula: , wherein, R is selected from one of a linear substituent of C0 to C5 alkyl or alkoxy, and a branched substituent of C0 to C5 alkyl or alkoxy; The hydroxyacrylate monomer in the branched acrylic resin A is selected from one or more of 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 5-hydroxypentyl acrylate.

[0008] Furthermore, in the negative photoresist composition provided by the present invention, by mass, the raw materials of the branched acrylic resin A include: 1 to 40 parts of epoxy acrylate monomer, 1 to 40 parts of long-chain acrylate monomer, 1 to 20 parts of styrene monomer, and 1 to 30 parts of hydroxyacrylate monomer.

[0009] Furthermore, in the negative photoresist composition provided by the present invention, the branched acrylic resin A is prepared by a polymerization reaction of an epoxy acrylate monomer, a long-chain acrylate monomer, a styrene monomer, and a hydroxy acrylate monomer under the action of a radical initiator and an organic solvent; The radical initiator is an azo initiator and / or a peroxide initiator; The organic solvent is selected from one or more of diethylene glycol alkyl ether compounds, dipropylene glycol alkyl ether compounds, propylene glycol monoalkyl ether compounds, propylene glycol monoalkyl ether acetate compounds, N,N-dimethylamide compounds, lactate compounds, and ketone compounds; The azo initiator is selected from one or more of 2,2'-azobis(isobutyric acid) dimethyl, 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and azodiisobutyric acid methyl ester; The peroxide initiator is selected from one or more of benzoyl peroxide, lauroyl peroxide, tert-butyl perbenzoate, tert-butyl peroxy-2-ethylhexanoate, potassium persulfate, and sodium persulfate.

[0010] Furthermore, in the negative photoresist composition provided by the present invention, the epoxy acrylate monomer in the branched acrylic resin B is selected from one or more of epoxy methacrylate, glycidyl acrylate, tetrahydrofurfuryl methacrylate, glycidyl ether 4-hydroxybutyl acrylate, and (3,4-epoxycyclohexyl)methyl acrylate; The diacrylate monomer in the branched acrylic resin B is selected from one or more of ethylene glycol diacrylate, triethylene glycol dimethoxy acrylate, ethylene glycol dimethacrylate, tris(ethylene glycol) diacrylate, tetraethylene glycol diacrylate, neopentyl glycol diacrylate, dipropylene glycol diacrylate, bisphenol A glycerol dimethacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, and 1,10-decanediol dimethacrylate; The styrene monomer in the branched acrylic resin B is selected from the following general formula: , wherein R is selected from one of a linear substituent of C0-C3 alkyl or alkoxy, and a branched substituent of C0-C3 alkyl or alkoxy.

[0011] Furthermore, in the negative photoresist composition provided by the present invention, by mass, the raw materials of the branched acrylic resin B include: 1-40 parts of epoxy acrylate monomer, 1-70 parts of diacrylate monomer, and 1-20 parts of styrene monomer.

[0012] Furthermore, in the negative photoresist composition provided by the present invention, the branched acrylic resin B is prepared by a polymerization reaction of an epoxy acrylate monomer, a diacrylate monomer, and a styrene monomer under the action of a radical initiator and an organic solvent; The radical initiator is an azo initiator and / or a peroxide initiator; The organic solvent is selected from one or more of diethylene glycol alkyl ether compounds, dipropylene glycol alkyl ether compounds, propylene glycol monoalkyl ether compounds, propylene glycol monoalkyl ether acetate compounds, N,N-dimethylamide compounds, lactate compounds, and ketone compounds; The azo initiator is selected from one or more of 2,2'-azobis(isobutyric acid)dimethyl, 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and methyl azodisobutyrate; The peroxide initiator is selected from one or more of benzoyl peroxide, lauroyl peroxide, tert-butyl perbenzoate, tert-butyl peroxy-2-ethylhexanoate, potassium persulfate, and sodium persulfate.

[0013] Furthermore, in the negative photoresist composition provided by the present invention, the molecular weight of the branched acrylic resin A is Mn = 3000 - 7000, and the molecular weight distribution is PDI = 1.2 - 2.0; The molecular weight of the branched acrylic resin B is Mn = 3000 - 6000, and the molecular weight distribution is PDI = 1.2 - 1.8.

[0014] In a second aspect, the present invention provides a patterning method, including: spin-coating the negative photoresist composition according to any one of claims 1 - 9 on a substrate, heating and drying, mask exposure, photocuring, developing, and forming a photoresist pattern; The spin-coating time is 15 s, and the spin-coating speed is 315 rpm; The heating and drying time is 180 s, and the heating and drying temperature is 90 °C; The exposure time is 15 s; The photocuring temperature is 120 °C; The developing solution is a tetramethylammonium hydroxide solution, and the developing time is 60 s.

[0015] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages: The negative photoresist composition prepared by the present invention can prepare patterned photoresists with different adhesion forces by adjusting the different mass ratios of the branched acrylic resin A and the branched acrylic resin B. The formed patterns have good resolution and neat edges and are not easy to fall off. Since there are no small molecule additives in the photoresist composition, it has good thermal stability during the photolithography process. After comprehensively testing the patterns of the negative photoresist composition after lithography, good resolution and edge roughness can be maintained on the basis of ensuring good adhesion force. Detailed implementation mode

[0016] Next, the technical solutions of the present invention will be described in conjunction with the embodiments. However, the present invention is not limited to the following embodiments. The experimental methods and detection methods described in each embodiment are all conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0017] The negative photoresist composition described in the present invention comprises a branched acrylic resin A, a branched acrylic resin B, a photoacid generator and a solvent; In terms of mass parts, the negative photoresist composition described in the present invention includes: 10-30 parts of branched acrylic resin A, 10-20 parts of branched acrylic resin B, 1-5 parts of photoacid generator and 49-75 parts of organic solvent.

[0018] (1) Branched acrylic resin A The branched acrylic resin A comprises an epoxy acrylate monomer (A-I), a long-chain acrylate monomer (A-II), a styrene monomer (A-III) and a hydroxy acrylate monomer (A-IV); In terms of mass parts, the branched acrylic resin A includes: 1-40 parts of epoxy acrylate monomer (A-I), 1-40 parts of long-chain acrylate monomer (A-II), 1-20 parts of styrene monomer (A-III) and 1-30 parts of hydroxy acrylate monomer (A-IV); The molecular weight of the branched acrylic resin A is Mn = 3000-7000, and PDI = 1.2-2.0; The epoxy acrylate monomer (A-I) is selected from one or more of methacrylic acid epoxy ester, glycidyl acrylate, tetrahydrofurfuryl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, (3,4-epoxycyclohexyl) methyl acrylate; The long-chain acrylate monomer (A-II) is selected from one or more of ethyl acrylate, butyl acrylate, amyl acrylate, ethyl methacrylate, butyl methacrylate, lauryl acrylate, lauryl methacrylate, 3,5,5-trimethylhexyl acrylate, diethylene glycol butyl ether methacrylate, hexyl methacrylate, n-octyl acrylate; The styrene monomer (A-III) has a structure as shown in Formula 1: , wherein, R is selected from one of a linear substituent of C0-C5 alkyl or alkoxy, and a branched substituent of C0-C5 alkyl or alkoxy; The hydroxyacrylate monomer (A-IV) is selected from one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and 5-hydroxypentyl acrylate; The preparation method of the branched acrylic resin A includes: carrying out a polymerization reaction on an epoxy acrylate monomer (A-I), a long-chain acrylate monomer (A-II), a styrene monomer (A-III), a hydroxyacrylate monomer (A-IV), a radical initiator, and an organic solvent.

[0019] (2) Branched acrylic resin B The branched acrylic resin B contains an epoxy acrylate monomer (B-I), a diacrylate monomer (B-II), and a styrene monomer (B-III); By mass, the branched acrylic resin B includes: 1-40 parts of the epoxy acrylate monomer (B-I), 1-70 parts of the diacrylate monomer (B-II), and 1-20 parts of the styrene monomer (B-III); The molecular weight of the branched acrylic resin B is Mn = 3000-6000, and PDI = 1.2-1.8; The epoxy acrylate monomer (B-I) is one or more of epoxy methacrylate, glycidyl acrylate, tetrahydrofurfuryl methacrylate, glycidyl ether of 4-hydroxybutyl acrylate, and (3,4-epoxycyclohexyl)methyl acrylate; The diacrylate monomer (B-II) is one or more of ethylene glycol diacrylate, triethylene glycol dimethoxyacrylate, ethylene glycol dimethacrylate, tris(ethylene glycol) diacrylate, tetraethylene glycol diacrylate, neopentyl glycol diacrylate, dipropylene glycol diacrylate, bisphenol A glycerol dimethacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, and 1,10-decanediol dimethacrylate; The styrene monomer (A-III) has a structure as shown in Formula 1: , wherein, R is selected from one of a linear substituent of C0-C3 alkyl or alkoxy, and a branched substituent of C0-C3 alkyl or alkoxy; The preparation method of the branched acrylic resin B includes: carrying out a polymerization reaction on the epoxy acrylate monomer (B-I), the diacrylate monomer (B-II), and the styrene monomer (B-III), a radical initiator, and an organic solvent.

[0020] In the preparation methods of the branched acrylic resin A and the branched acrylic resin B, the radical initiator is an azo initiator and / or a peroxide initiator; The azo initiator is selected from one or more of 2,2'-azobis(isobutyric acid)dimethyl, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylpentanenitrile), and methyl azodimethylisobutyrate; The peroxide initiator is selected from one or more of organic peroxides such as benzoyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, and tert-butyl peroxy-2-ethylhexanoate, and persulfates such as potassium persulfate and sodium persulfate.

[0021] When using the above radical initiator for the polymerization reaction, a chain transfer agent can be arbitrarily added, such as 2-mercaptoethanol, butyl mercaptan, n-dodecyl mercaptan, α-methylstyrene dimer, etc.

[0022] In the preparation methods of the branched acrylic resin A and the branched acrylic resin B, the organic solvent is selected from one or more of diethylene glycol alkyl ether compounds, dipropylene glycol alkyl ether compounds, propylene glycol monoalkyl ether compounds, propylene glycol monoalkyl ether acetate compounds, N,N-dimethylamide compounds, lactate compounds, and ketone compounds; The diethylene glycol alkyl ether compounds are diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol methyl ethyl ether; the dipropylene glycol alkyl ether solvents are dipropylene glycol dimethyl ether and dipropylene glycol diethyl ether; The propylene glycol monoalkyl ether compounds are propylene glycol monomethyl ether and propylene glycol monoethyl ether; the propylene glycol monoalkyl ether acetate solvents are propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, etc.; The N,N-dimethylamide compounds are N,N-dimethylformamide and N,N-dimethylacetamide; The lactate compounds are methyl lactate and ethyl lactate; the ketone compounds are cyclobutanone and cyclopentanone.

[0023] (3) Photoacid generator The photoacid generator is an iodonium salt and / or a sulfonium salt; The iodonium salt is selected from one or more of diphenyl iodonium hexafluoroantimonate, diphenyl iodonium hexafluorophosphate, diphenyl iodonium hexafluoroarsenate, diphenyl iodonium tetrafluoroborate, dimethylphenyl iodonium hexafluoroarsenate, and di-tert-butylphenyl iodonium hexafluorophosphate; The sulfonium salt is selected from one or more of triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium tetrafluoroborate, 4-methylphenyldiphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluorophosphate, diphenylsulfonium salt, and 4-(phenylthio)phenylsulfonium hexafluorophosphate.

[0024] (4) Solvent The solvent is selected from one or more of dichloromethane, chloroform, tetrahydrofuran, benzene, toluene, butyrolactone, propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, cyclopentanone, butyl acetate, methyl isobutyl ketone, 2-pentanone, 4-methyl-2-pentanone, cyclohexanone, 2-heptanone, γ-butyrolactone, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, and N,N-dimethylformamide.

[0025] Example 1 This example provides a method for synthesizing branched acrylic resin A.

[0026] Under nitrogen protection, 150.0 g of glycidyl methacrylate, 150.0 g of ethyl methacrylate, 45.0 g of styrene, 40.0 g of 2-hydroxyethyl acrylate, 10.0 g of 2,2'-azobis(2,4-dimethylvaleronitrile), and 5.0 g of α-methylstyrene dimer were added to a 1 L three-necked flask. The temperature was raised to 85°C with stirring, and after reacting for 7 h, the temperature was lowered to room temperature to obtain branched acrylic resin solution A1. The molecular weight Mn of branched acrylic resin solution A1 was 3800, and PDI was 1.6.

[0027] Example 2 This example provides a method for synthesizing branched acrylic resin A.

[0028] Under nitrogen protection, 150.0 g of 4-hydroxybutyl glycidyl acrylate, 150.0 g of butyl methacrylate, 45.0 g of styrene, 40.0 g of 2-hydroxyethyl acrylate, 10.0 g of 2,2'-azobis(2,4-dimethylvaleronitrile), and 5.0 g of α-methylstyrene dimer were added to a 1 L three-necked flask. The temperature was raised to 85°C with stirring, and after reacting for 7 h, the temperature was lowered to room temperature to obtain branched acrylic resin solution A2. The molecular weight Mn of branched acrylic resin solution A2 was 5500, and PDI was 1.8.

[0029] Example 3 This example provides a method for synthesizing branched acrylic resin A.

[0030] Under nitrogen protection, 150.0 g of tetrahydrofurfuryl methacrylate, 150.0 g of ethyl methacrylate, 45.0 g of styrene, 40.0 g of hydroxypropyl acrylate, 10.0 g of 2,2'-azobis(2,4-dimethylvaleronitrile), and 5.0 g of α-methylstyrene dimer were added to a 1-L three-necked flask. The temperature was raised to 85 °C with stirring, and after reacting for 7 h, the temperature was lowered to room temperature to obtain branched acrylic resin solution A3. The molecular weight Mn of the branched acrylic resin solution A3 was 5000, and the PDI was 1.5.

[0031] Example 4 This example provides a method for synthesizing branched acrylic resin A.

[0032] Under nitrogen protection, 150.0 g of glycidyl methacrylate, 150.0 g of ethyl acrylate, 45.0 g of styrene, 40.0 g of hydroxypropyl acrylate, 10.0 g of 2,2'-azobis(2,4-dimethylvaleronitrile), and 5.0 g of α-methylstyrene dimer were added to a 1-L three-necked flask. The temperature was raised to 85 °C with stirring, and after reacting for 7 h, the temperature was lowered to room temperature to obtain branched acrylic resin solution A4. The molecular weight Mn of the branched acrylic resin solution A4 was 4000, and the PDI was 1.6.

[0033] Example 5 This example provides a method for synthesizing branched acrylic resin B.

[0034] Under nitrogen protection, 200.0 g of epoxy methacrylate, 150.0 g of ethylene glycol diacrylate, 35.0 g of styrene, 10.0 g of 2,2'-azobis(2,4-dimethylvaleronitrile), and 5.0 g of α-methylstyrene dimer were added to a 1-L three-necked flask. The temperature was raised to 85 °C with stirring, and after reacting for 7 h, the temperature was lowered to room temperature to obtain branched acrylic resin solution B1. The molecular weight Mn of the branched acrylic resin solution B1 was 4000, and the PDI was 1.5.

[0035] Example 6 This example provides a method for synthesizing branched acrylic resin B.

[0036] Under nitrogen protection, 200.0 g of glycidyl acrylate, 150.0 g of ethylene glycol diacrylate, 35.0 g of styrene, 10.0 g of 2,2'-azobis(2,4-dimethylvaleronitrile), and 5.0 g of α-methylstyrene dimer were added to a 1-L three-necked flask. The temperature was raised to 85 °C with stirring, and after reacting for 7 h, the temperature was lowered to room temperature to obtain branched acrylic resin solution B2. The molecular weight Mn of the branched acrylic resin solution B2 was 5000, and the PDI was 1.7.

[0037] Example 7 This example provides a method for synthesizing branched acrylic resin B.

[0038] Under nitrogen protection, 200.0 g of epoxy methacrylate, 150.0 g of ethylene glycol dimethacrylate, 35.0 g of styrene, 10.0 g of 2,2'-azobis(2,4-dimethylvaleronitrile), and 5.0 g of α-methylstyrene dimer were added to a 1 L three-necked flask. The mixture was heated to 85°C with stirring and reacted for 7 h, then cooled to room temperature to obtain branched acrylic resin solution B3. The molecular weight Mn of the branched acrylic resin solution B3 was 3,300, and the PDI was 1.8.

[0039] Example 8 This example provides a method for synthesizing branched acrylic resin B.

[0040] Under nitrogen protection, 200.0 g of tetrahydrofurfuryl methacrylate, 150.0 g of triethanol dimethacrylate, 35.0 g of styrene, 10.0 g of 2,2'-azobis(2,4-dimethylvaleronitrile), and 5.0 g of α-methylstyrene dimer were added to a 1 L three-necked flask. The mixture was heated to 85°C with stirring and reacted for 7 h, then cooled to room temperature to obtain branched acrylic resin solution B4. The molecular weight Mn of the branched acrylic resin solution B3 was 5,600, and the PDI was 1.4.

[0041] Example 9 This example provides a method for preparing a high-adhesion negative photoresist composition.

[0042] Under nitrogen protection, 30 g of branched acrylic resin A1, 10 g of branched acrylic resin B1, 5 g of diphenylsulfonium salt as a photoacid generator, and 55 g of cyclopentanone as a solvent were added to a 250 mL three-necked flask and dissolved clearly to obtain negative photoresist composition W1.

[0043] Examples 10 - 20 and Comparative Examples 1 - 8 For Examples 10 - 20 and Comparative Examples 1 - 8, the preparation method was the same as that of Example 9 to obtain negative photoresist compositions W2 - W20, except for the types and masses of the acrylic resins. The formulations of the negative photoresist compositions of Examples 10 - 20 and Comparative Examples 1 - 8 are shown in Table 1.

[0044] Table 1 Formulations of Negative Photoresist Compositions of Examples 9 - 20 and Comparative Examples 1 - 8

[0045] Example 21 This example provides a method for patterning a negative photoresist composition.

[0046] The photoresist composition W1 of Example 1 was spin-coated on a clean glass slide at a speed of 315 rpm for 15 s, pre-baked at 90 °C for 180 s. After pre-baking, maskless exposure was carried out for 15 s, and then dried and photocured at 120 °C. A 2.38% tetramethylammonium hydroxide solution (TMAH) was used as the developer for 60 s to obtain the test sample G1 after photolithographic patterning.

[0047] Example 22 - 32 Examples 22 to 32 were the same as Example 21, except that the negative photoresist compositions W2 - W12 of Examples 2 to 20 were selected for patterning to prepare the test samples G2 - G12 after photolithographic patterning.

[0048] Example 33 This example provides a test method for a negative photoresist composition and a test sample after photolithographic patterning.

[0049] (1) Gel Permeation Chromatography (GPC) Test The test was carried out using a GPC instrument of Agilent 1260 model. The chromatographic column was selected as Agilent Plege 3μmMIXED - D (specification: 300 mm × 7.5 mm) × 2. The mobile phase was tetrahydrofuran (THF), and the flow rate was set at 1.0 mL / min. The detector was a refractive index detector (RID detector), and the acquisition duration was 30 min. The workstation was operated and data - processed using AgilentGPC software.

[0050] (2) Edge Roughness Test An optical microscope (Primotech) was used to measure the edge roughness. The specific operation was to measure the actual length of a 5 - μm pattern, and then calculate the difference between the actual length and the theoretical length to evaluate the edge roughness.

[0051] (3) Photolithography Test A SUSS - MJB4 photolithography instrument was used for photolithography operations. During the photolithography process, a mixed line of i - line and g - line was used as the light source wavelength, and the exposure dose was controlled within the range of 30 - 70 mJ.

[0052] (4) Film Coating Test A MycroWS - 650MZ - 23NPPB film - coating instrument was used for film - coating operations. During film - coating, the rotation speed of the instrument was set within the range of 300 - 1000 rpm.

[0053] (5) Peeling Test The same optical microscope (Primotech) was used to carry out the Peeling test, and the specific operation method was carried out according to the instrument operation instructions and relevant test standards.

[0054] (6) Adhesion test The adhesion test uses a cross - cut tester, model BYK5123, with 11 cutting teeth and a tooth pitch of 1 mm. The tape used for the test is 3M610 tape. The test method and evaluation criteria strictly follow the GB / T9286 - 2021 standard.

[0055] (7) Film thickness test The film thickness is measured using a profilometer, model Bruker Dektak150. The film thickness data can be directly obtained through this instrument.

[0056] (8) Calculation of residual film rate The calculation method of the residual film rate is the ratio of the film thickness before baking to the film thickness of the coating film, so as to evaluate the residual film situation.

[0057] Comparative example 9 The purchased photoresist composition with polyisoprene as the main resin was spin - coated on a clean glass slide at a speed of 300 rpm for 15 s, pre - baked at 90 °C for 180 s. After pre - baking, mask - type exposure was carried out for 20 s, and then dried and photocured at 120 °C. A 2.38% tetramethylammonium hydroxide solution (TMAH) was used as the developer for 60 s. The test sample G13 after photolithographic patterning was obtained.

[0058] Comparative examples 10 - 17 Comparative examples 10 - 17 are the same as Example 21, except that the negative photoresist compositions W13 - W20 of Comparative examples 1 - 8 were used for patterning to prepare the test samples G14 - G21 after photolithographic patterning.

[0059] The performance results of the test samples of Examples 21 - 32 and Comparative examples 9 - 17 are shown in Table 2.

[0060] Table 2 Performance test results of test samples G of Examples 21 - 32 and Comparative examples 9 - 17

[0061] Note: (1) Adhesion grading evaluation criteria: ++++ indicates that the edge is neat and smooth, and no grid falls off; +++ indicates that the total peeling area in the cross-cut area does not exceed 5%; ++ indicates that the total peeling area in the cross-cut area is greater than 5% and does not exceed 15%; + indicates that the total peeling area in the cross-cut area is greater than 15% but does not exceed 35%. (2) Edge roughness grading evaluation criteria: **** indicates that the pattern edge is flat and smooth, CD loss ≤ 0.5 μm; *** indicates that there are a small number of burrs on the pattern edge, 0.5 μm < CD loss ≤ 1.0 μm; ** indicates that the pattern edge is slightly deformed, 1.0 μm < CD loss ≤ 1.5 μm; * indicates that the pattern edge is completely deformed, 1.5 μm < CD loss.

[0062] As can be seen from Table 2, the resolution of Examples 21 to 32 is relatively high. Under mask patterning, the highest resolution can reach 1.5 μm, with good adhesion and edge roughness, and no Peeling occurs, indicating that the patterned photoresist prepared by the present invention meets the process condition requirements. The resolution of Comparative Example 9 is relatively poor compared to the examples, the adhesion decreases, and the roughness of the pattern edge increases. In Comparative Examples 10 to 13, the main resin in the negative photoresist composition is a single branched acrylic resin A, and the roughness of the pattern edge after lithography is relatively large and the resolution is poor. In Comparative Examples 14 to 17, the main resin in the photoresist composition is a single branched acrylic resin B, and the pattern edge is slightly deformed and the adhesion is poor after lithography, with Peeling defects.

[0063] The above-described embodiments are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by relevant deductions and substitutions made by those of ordinary skill in the art under the premise of not making creative efforts based on the concept of the present invention fall within the scope of protection of the present invention.

Claims

1. A negative photoresist composition, characterized in that, It comprises: branched acrylic resin A, branched acrylic resin B, photoacid generator and solvent; The branched acrylic resin A is prepared by a polymerization reaction of epoxy acrylate monomer, long-chain acrylate monomer, styrene monomer and hydroxyacrylate monomer; The branched acrylic resin B is prepared by a polymerization reaction of epoxy acrylate monomer, diacrylate monomer and styrene monomer; The photoacid generator is iodonium salt and / or sulfonium salt; The solvent is selected from one or more of dichloromethane, chloroform, tetrahydrofuran, benzene, toluene, butyrolactone, propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, cyclopentanone, butyl acetate, methyl isobutyl ketone, 2-pentanone, 4-methyl-2-pentanone, cyclohexanone, 2-heptanone, γ-butyrolactone, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate and N,N-dimethylformamide.

2. The negative photoresist composition according to claim 1, characterized in that, By mass, the photoresist composition comprises: 10 to 30 parts of branched acrylic resin A, 10 to 20 parts of branched acrylic resin B, 1 to 5 parts of photoacid generator, and 49 to 75 parts of organic solvent.

3. The negative photoresist composition according to claim 1, wherein The epoxy acrylate monomer in the branched acrylic resin A is selected from one or more of epoxy methacrylate, glycidyl acrylate, tetrahydrofurfuryl methacrylate, glycidyl 4-hydroxybutyl acrylate, (3,4-epoxycyclohexyl)methyl acrylate; The long-chain acrylate monomer in the branched acrylic resin A is selected from one or more of ethyl acrylate, butyl acrylate, amyl acrylate, ethyl methacrylate, butyl methacrylate, lauryl acrylate, lauryl methacrylate, 3,5,5-trimethylhexyl acrylate, diethylene glycol butyl ether methacrylate, hexyl methacrylate, n-octyl acrylate; The styrene monomer in the branched acrylic resin A is selected from the following general formula: ， wherein, R is selected from one of C0-C5 alkyl or alkoxy linear substituents, C0-C5 alkyl or alkoxy branched substituents; The hydroxyacrylate monomer in the branched acrylic resin A is selected from one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, 5-hydroxypentyl acrylate.

4. The negative photoresist composition according to claim 3, characterized in that, By mass, the raw materials of the branched acrylic resin A include: 1 to 40 parts of epoxy acrylate monomer, 1 to 40 parts of long-chain acrylate monomer, 1 to 20 parts of styrene monomer and 1 to 30 parts of hydroxyacrylate monomer.

5. The negative photoresist composition according to claim 4, characterized in that, The branched acrylic resin A is prepared by a polymerization reaction of epoxy acrylate monomer, long-chain acrylate monomer, styrene monomer and hydroxyacrylate monomer under the action of a radical initiator and an organic solvent; The radical initiator is an azo initiator and / or a peroxide initiator; The organic solvent is selected from one or more of diethylene glycol alkyl ether compounds, dipropylene glycol alkyl ether compounds, propylene glycol monoalkyl ether compounds, propylene glycol monoalkyl ether acetate compounds, N,N-dimethylamide compounds, lactate compounds, ketone compounds; The azo initiator is selected from one or more of dimethyl 2,2'-azobis(isobutyrate), 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and methyl azodisobutyrate; The peroxide initiator is selected from one or more of benzoyl peroxide, lauroyl peroxide, tert-butyl perbenzoate, tert-butyl peroxy-2-ethylhexanoate, potassium persulfate, and sodium persulfate.

6. The negative photoresist composition according to claim 1, characterized in that, The epoxy acrylate monomer in the branched acrylic resin B is selected from one or more of epoxy methacrylate, glycidyl acrylate, tetrahydrofurfuryl methacrylate, glycidyl ether of 4-hydroxybutyl acrylate, and (3,4-epoxycyclohexyl)methyl acrylate; The diacrylate monomer in the branched acrylic resin B is selected from one or more of ethylene glycol diacrylate, triethylene glycol dimethoxyacrylate, ethylene glycol dimethacrylate, tri(ethylene glycol) diacrylate, tetraethylene glycol diacrylate, neopentyl glycol diacrylate, dipropylene glycol diacrylate, bisphenol A glycerol dimethacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, and 1,10-decanediol dimethacrylate; The styrene monomer in the branched acrylic resin B is selected from the following general formula: ， Wherein, R is selected from one of a linear substituent of C0-C3 alkyl or alkoxy, and a branched substituent of C0-C3 alkyl or alkoxy.

7. The negative photoresist composition according to claim 6, characterized in that, By mass, the raw materials of the branched acrylic resin B include: 1-40 parts of epoxy acrylate monomer, 1-70 parts of diacrylate monomer, and 1-20 parts of styrene monomer.

8. The negative photoresist composition according to claim 7, wherein The branched acrylic resin B is prepared by a polymerization reaction of an epoxy acrylate monomer, a diacrylate monomer, and a styrene monomer under the action of a radical initiator and an organic solvent; The radical initiator is an azo initiator and / or a peroxide initiator; The organic solvent is selected from one or more of diethylene glycol alkyl ether compounds, dipropylene glycol alkyl ether compounds, propylene glycol monoalkyl ether compounds, propylene glycol monoalkyl ether acetate compounds, N,N-dimethylamide compounds, lactate compounds, and ketone compounds; The azo initiator is selected from one or more of dimethyl 2,2'-azobis(isobutyrate), 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and methyl azodisobutyrate; The peroxide initiator is selected from one or more of benzoyl peroxide, lauroyl peroxide, tert-butyl perbenzoate, tert-butyl peroxy-2-ethylhexanoate, potassium persulfate, and sodium persulfate.

9. The negative photoresist composition according to claim 1, wherein The molecular weight of the branched acrylic resin A is Mn = 3000-7000, and the molecular weight distribution is PDI = 1.2-2.0; The molecular weight of the branched acrylic resin B is Mn = 3000-6000, and the molecular weight distribution is PDI = 1.2-1.

8.

10. A patterning method, characterized in that, Including: Spin-coat the negative photoresist composition according to any one of claims 1 to 9 on a substrate, heat and dry, perform mask exposure, photocure, and develop to form a photoresist pattern; The spin-coating time is 15 s and the spin-coating speed is 315 rpm; The heating and drying time is 180 s and the heating and drying temperature is 90 °C; The exposure time is 15 s; The photocuring temperature is 120 °C; The developing solution is a tetramethylammonium hydroxide solution and the developing time is 60 s.

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