Chemical amplification type negative polyimide photoresist, preparation method and application thereof

Abstract

The application discloses a chemical amplification type negative polyimide photoresist and a preparation method and application thereof. The chemical amplification type negative polyimide photoresist is composed of the following (1) or (2): (1) a polyimide precursor solid resin, a photoacid generator, a photo-crosslinking agent and an organic solvent; (2) a polyimide precursor solid resin, a photoacid generator, a photo-crosslinking agent, a functional additive and an organic solvent; the functional additive is at least one of a photosensitive accelerator, an adhesion aid and an inhibitor; the inhibitor is a thermal polymerization inhibitor and / or an alkaline inhibitor; the polyimide precursor solid resin is made of aromatic diacyl dichloride, aromatic diamine and a blocking agent; the aromatic diacyl dichloride is made of aromatic diacid diester and an acyl chloride reagent; and the aromatic diacid diester is made of aromatic tetracarboxylic dianhydride and a lower aliphatic alcohol.

Description

Technical Field

[0001] This invention relates to a chemically amplified negative polyimide photoresist and its preparation method and application, belonging to the field of polymer material preparation technology. Background Technology

[0002] Photosensitive polyimide coating (PSPI) can be applied to the surface of substrates such as single-crystal silicon to form a liquid film. After pre-baking, exposure, development, and rinsing, a three-dimensional resin pattern can be formed on the substrate surface. The polyimide resin obtained after high-temperature curing has advantages such as high temperature resistance, high strength and toughness, high electrical insulation, and high chemical corrosion resistance. It is widely used in the manufacturing and packaging of ultra-large-scale integrated circuits (ULSI), mainly including interlayer insulating dielectric films, α-particle barriers, and stress relief and buffer coatings in multilayer metal interconnect circuits (RDL).

[0003] With the rapid development of advanced electronic packaging technology, higher demands are being placed on PSPI materials. For many advanced packaging forms, such as WL-CSP (Wafer-level Chip Scale Packaging) and 3D packaging, not only is excellent photolithography processability required for PSPI, but the cured polymer resin also needs high heat resistance, excellent adhesion, and chemical corrosion resistance. To meet the requirements of special packaging structures such as chip stacking and MEMS, photolithographic patterns need to have high thickness, high aspect ratio, and high film retention. Traditional PSPI resins, due to their low photon utilization efficiency, require very high exposure energy to create thick-film patterns, and their photolithographic pattern aspect ratio and film retention are difficult to meet the special requirements of advanced packaging. Compared with traditional PSPI resin film-forming adhesives, chemically amplified photosensitive polyimide (CA-PSPI) has higher sensitivity because a single photon can trigger a chain cross-linking reaction, resulting in photolithographic patterns with a high aspect ratio and a low curing shrinkage rate.

[0004] Watanabe, Y. et al. (Journal of Polymer Science Part A: Polymer Chemistry, 2005, 43, 593–599 and Polymer Journal, 2005, 37, 270–276) reported a method for preparing a negative CA-PSPI photoresist. A homogeneous negative CA-PSPI film was formed by dissolving polyamic acid (PAA) resin, a crosslinker, and a photoacid generator in an organic solvent. The PAA resin was formed by polycondensation of PMDA and 4,4′-diaminodiphenyl ether (ODA) dissolved in N,N-dimethylacetamide (DMAc). The negative CA-PSPI film was then formed by dissolving PAA resin (65 wt.%), a crosslinker (MBHP, 25 wt.%), and a photoacid generator (PTMA, 10%) in 2-methoxyethanol (13 wt.%). Spin-coating this onto a silicon wafer surface, followed by pre-baking, exposure (g-line), post-baking, and development, yields a photolithographic pattern with a resolution of 10 μm. Additionally, a semi-aromatic polyamic acid resin was synthesized by dissolving an alicyclic tetracarboxylic dianhydride and an aromatic diamine containing adamantane in N-methylpyrrolidone (NMP) solvent via a condensation reaction. This PAA resin (60 wt.%), a crosslinking agent (MBHP, 30 wt.%), and a photoacidifier (PTMA, 10%) were dissolved in 2-methoxyethanol to form a negative CA-PSPI layer film. Spin-coating this onto a silicon wafer surface, followed by pre-baking, exposure (g-line), post-baking, and development in an alkaline aqueous solution, yields a photolithographic pattern with a resolution of 15 μm.

[0005] Cai Zhengyu et al. (CN101055420) disclosed a negative photosensitive composition and its photolithographic printing method. The photosensitive composition consists of a polyimide resin containing carboxyl or hydroxyl groups, a polyhydroxy crosslinking agent, and a photoacid-generating agent (PTMA). The photolithographic pattern formed after development in an alkaline aqueous solution and curing at 230°C has an inverted trapezoidal shape.

[0006] Hiroyuki Urano et al. (CN110016136 B) disclosed a chemically amplified photosensitive polyimide resin that can be cured at a low temperature of 200℃ and developed in an alkaline aqueous solution. A polyamic acid resin is formed by polycondensation of a siloxane-containing aromatic diamine or aliphatic diamine with 3,3',4,4'-oxydiphthalic dianhydride (ODPA) and a siloxane-containing tetracarboxylic dianhydride in NMP solvent; then, xylene is added and subjected to high-temperature reflux imidization to form a polyimide resin. The negative photosensitive polyimide resin prepared by mixing this resin with a photoacid generator, a polyalkoxy crosslinking agent, and an epoxy crosslinking agent achieves a photolithographic resolution of 8 μm, an aspect ratio exceeding 1:1, and a curing shrinkage rate of 10%-15%.

[0007] Saker et al. (CN103913951 B) disclosed a sulfur-containing acid-generating agent and a photoresist containing it. After exposure to light, the acid generated by this agent migrates to unexposed areas and can displace weak acids, forming a weak acid and a strong acid salt. The weak acid does not participate in the crosslinking reaction of the negative photoresist, thus improving the contrast and resolution of the photoresist.

[0008] While the aforementioned patents have some features, they cannot meet the usage requirements of advanced packaging technologies such as chip-level packaging and MEMS. Summary of the Invention

[0009] The purpose of this invention is to provide a chemically amplified negative polyimide photoresist, its preparation method, and its application. This chemically amplified negative polyimide photoresist has high photolithographic pattern resolution, low curing pattern shrinkage, high heat resistance, good chemical corrosion resistance, and good adhesion to different metal interfaces, making it suitable for applications in semiconductor chip manufacturing, advanced packaging, flat panel displays, and other fields.

[0010] In a first aspect, the present invention provides a chemically amplified negative polyimide photoresist, which is as follows (1) or (2):

[0011] (1) It is composed of polyimide precursor solid resin, photoacid generator, photocrosslinking agent and organic solvent;

[0012] (2) It is composed of polyimide precursor solid resin, photoacid generator, photocrosslinking agent, functional additives and organic solvent; the functional additives are at least one of photosensitizing promoter, adhesion promoter and inhibitor; the inhibitors are thermal polymerization inhibitors and / or alkaline inhibitors;

[0013] The polyimide precursor solid resin is made from aromatic diacyl chloride diester, aromatic diamine and end-capping agent; the aromatic diacyl chloride diester is made from aromatic diacid diester and acyl chloride reagent; the aromatic diacid diester is made from aromatic tetracarboxylic dianhydride and lower fatty alcohol.

[0014] In the above-mentioned chemically amplified negative polyimide photoresist, the weight-average molecular weight of the polyimide precursor solid resin is 5000-100000 g / mol, preferably 10000-50000 g / mol.

[0015] The molar ratio of the aromatic diacyl chloride diester to the aromatic diamine can be 1:0.8 to 1.2, specifically 1:1;

[0016] The aromatic diamine may be p-phenylenediamine (PDA), 4,4-diaminodiphenyl ether (4,4-ODA), 3,4-diaminodiphenyl ether (3,4-ODA), 1,4-bis(4-aminophenoxy)-benzene (1,3,4-APB), 1,4-bis(4-aminophenoxy)-benzene (1,4,4-APB), 2,2-bis(4-aminophenyl)propane (APP), 2,2-bis[4-(4-aminophenoxy)phenyl)]propane (BAPP), 2,2-bis(4-aminophenyl)hexafluoropropane (6F-APP), 2,2-bis[4-(4-aminophenoxy)phenyl)]hexafluoropropane (6F-BAPP), 2,2'-bis(trifluoromethyl)diaminobiphenyl (TFMB), 1,3-bis(3-aminopropyl)tetramethyldisiloxane, At least one of 1,3-bis(3-aminopropyl)tetraphenyldisiloxane, 1,3-bis(3-aminophenoxy)tetramethyldisiloxane and 1,3-bis(4-aminophenoxy)tetramethyldisiloxane;

[0017] The capping agent may be at least one selected from phthalic anhydride, 3-methylphthalic anhydride, 4-methylphthalic anhydride, acetic anhydride, propionic anhydride, aniline, 3-methylaniline, 4-methylaniline, methylamine, ethylamine, and propylamine; the molar ratio of the capping agent to the aromatic diamine may be 0–70:100, preferably 0–50:100, to achieve the aforementioned molecular weight range;

[0018] The molar ratio of the aromatic diacid diester to the acyl chloride reagent can be 1:1.5 to 3, specifically 1:2;

[0019] The acyl chloride reagent may be thionyl chloride, phosphorus oxychloride, phosphorus pentachloride, oxalyl chloride, phosgene, diphosgene, or triphosgene;

[0020] The molar ratio of the aromatic tetracarboxylic dianhydride to the lower fatty alcohol can be 1:1 to 4, specifically 1:1;

[0021] The aromatic tetracarboxylic dianhydride may be at least one selected from the following: pyromellitic dianhydride (PMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (OPDA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride (BFDA), 2,2-bis(3,4-phthalic anhydride)propane (BAPPA), and 2,2-bis(3,4-phthalic anhydride)-1,1,1,3,3,3-hexafluoropropane (6FPA);

[0022] The lower fatty alcohol may be at least one of methanol, ethanol, propanol, isopropanol, n-butanol, and tert-butanol.

[0023] In the above-mentioned chemically amplified negative polyimide photoresist, the mass fractions of each component can be as follows: 100 parts of polyimide precursor solid resin, 1-30 parts of photoacid generator, 5-30 parts of photocrosslinking agent, 100-300 parts of organic solvent, and 0-30 parts of functional additives.

[0024] Preferably, the mass fractions of each component are as follows: 100 parts of polyimide precursor solid resin, 5-20 parts of photoacid generator, 10-40 parts of photocrosslinking agent, 200 parts of organic solvent, and 0-10 parts of functional additives.

[0025] The chemically amplified negative polyimide photoresist may specifically be any one of the following 1)-10):

[0026] 1) The chemically amplified negative polyimide photoresist is composed of the following components in parts by weight:

[0027] 100 parts of polyimide precursor solid resin, 10 parts of photoacid-generating agent, 20 parts of photocrosslinking agent, and 200 parts of organic solvent;

[0028] 2) The chemically amplified negative polyimide photoresist is composed of the following components in parts by weight:

[0029] 100 parts of polyimide precursor solid resin, 10 parts of photoacid generator, 20 parts of photocrosslinking agent, 200 parts of organic solvent, and 2 parts of photosensitizing accelerator;

[0030] 3) The chemically amplified negative polyimide photoresist is composed of the following components in parts by weight:

[0031] 100 parts of polyimide precursor solid resin, 10 parts of photoacid generator, 20 parts of photocrosslinking agent, 200 parts of organic solvent, and 3 parts of adhesive aid;

[0032] 4) The chemically amplified negative polyimide photoresist is composed of the following components in parts by weight:

[0033] 100 parts of polyimide precursor solid resin, 10 parts of photoacid generator, 20 parts of photocrosslinking agent, 200 parts of organic solvent, and 1 part of thermal polymerization inhibitor;

[0034] 5) The chemically amplified negative polyimide photoresist is composed of the following components in parts by weight:

[0035] 100 parts of polyimide precursor solid resin, 10 parts of photoacid generator, 20 parts of photocrosslinking agent, 200 parts of organic solvent, 2 parts of photosensitizing accelerator, and 3 parts of adhesion promoter;

[0036] 6) The chemically amplified negative polyimide photoresist is composed of the following components in parts by weight:

[0037] 100 parts of polyimide precursor solid resin, 5 parts of photoacid generator, 10 parts of photocrosslinking agent, 200 parts of organic solvent, 2 parts of photosensitizing accelerator, and 3 parts of adhesive aid;

[0038] 7) The chemically amplified negative polyimide photoresist is composed of the following components in parts by weight:

[0039] 100 parts of polyimide precursor solid resin, 20 parts of photoacid generator, 40 parts of photocrosslinking agent, 200 parts of organic solvent, 2 parts of photosensitizing accelerator, and 3 parts of adhesive aid;

[0040] 8) The chemically amplified negative polyimide photoresist is composed of the following components in parts by weight:

[0041] 100 parts of polyimide precursor solid resin, 10 parts of photoacid generator, 20 parts of photocrosslinking agent, 200 parts of organic solvent, 2 parts of photosensitizing accelerator, 3 parts of adhesive agent, and 1 part of thermal polymerization inhibitor;

[0042] 9) The chemically amplified negative polyimide photoresist is composed of the following components in parts by weight:

[0043] 100 parts of polyimide precursor solid resin, 10 parts of photoacid generator, 20 parts of photocrosslinking agent, 200 parts of organic solvent, 2 parts of photosensitizing accelerator, 3 parts of adhesive, 1 part of thermal polymerization inhibitor, and 4 parts of alkaline inhibitor.

[0044] 10) The chemically amplified negative polyimide photoresist is composed of the following components in parts by weight:

[0045] 100 parts of polyimide precursor solid resin, 14 parts of photoacid generator, 20 parts of photocrosslinking agent, 200 parts of organic solvent, 2 parts of photosensitizing accelerator, 3 parts of adhesive agent, and 1 part of thermal polymerization inhibitor.

[0046] In the aforementioned chemically amplified negative polyimide photoresist, the photoacid generator can be a ium salt, oxime ester compound, coumarin, iminosulfonic acid, or other photoacid generators. Specifically, it can be Irgacure PAG 103, Irgacure PAG 121, Irgacure PAG 169, Irgacure PAG 250, Irgacure PAG 290, diphenyliodonium hexafluorophosphate, tri-tolylsulfonium hexafluorophosphate, di(3-methylphenyl)hexafluorophosphate, bis(4-tert-butylphenyl)iodonium hexafluorophosphate, 4,4'-xylyliodonium hexafluorophosphate, di(4-tert-butylphenyl)hexafluorophosphate, (2-naphthyl)(2, 4,6-Trimethylphenyl)hexafluorophosphate iodine, (4-biphenyl)(2,4,6-trimethylphenyl)hexafluorophosphate iodine, di(3-methylphenyl)hexafluorophosphate iodine, di(2-methylphenyl)hexafluorophosphate iodine, 4-octyloxydiphenyliodohexafluoroantimonate, diphenyliodonitrate, diphenyl(trifluoromethyl)sulfonium trifluoromethanesulfonate, tri-p-tolylsulfonium trifluoromethanesulfonate, (4-methoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, 1-naphthyldiphenylsulfonium trifluoromethanesulfonate, tri(4- tert-butylphenyl)sulfonium trifluoromethanesulfonate, (4-phenoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, bis[4-(1,1-dimethylethyl)phenyl]iodonium trifluoromethanesulfonate, (2-tolyl)(2,4,6-trimethylphenyl)iodonium trifluoromethanesulfonate, phenyl(2,4,6-trimethoxyphenyl)iodonium p-toluenesulfonate, bis(4-tert-butylphenyl)iodonium p-toluenesulfonate, diphenyliodonium p-toluenesulfonate, N-hydroxynaphthalimide trifluoromethanesulfonate, 2 At least one of the following: 4-bis(trichloromethyl)-6-p-methoxystyryl-S-triazine, N-hydroxy-5-norbornene-2,3-diamide nonafluorobutane sulfonic acid, triphenylsulfonium perfluorobutylsulfonate, bis(4-tert-butylphenyl)iodonium perfluoro-1-butanesulfonic acid, diphenyliodoacyl chloride, and its weak acid salts (such as salicylic acid, formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, and adipic acid) composed of iodonium salts, sulfonium salts, phosphonium salts, ammonium salts, or diazomonium salts.

[0047] In the aforementioned chemically amplified negative polyimide photoresist, the photocrosslinking agent can be a polyhydroxy or polymethoxy monomer, specifically Bis-Z, BisP-EZ, TekP-4HBPA, TrisP-HAP, TrisP-PA, TrisP-SA, TrisOCR-PA, BisOCHP-Z, BisP-MZ, BisP-PZ, BisP-IPZ, BisOCP-IPZ, BisP-CP, BisRS-2P, BisRS-3P, BisP-OCHP, methylenetri-FR-CR, BisRS-26X, DML-MBPC, DML-MBOC, DML-OCHP, DML-PCHP, DML-PC, DML-PTBP, DML-34X, DML-EP, DML-POP, dihydroxymethyl-BisOC-P, DML-PFP, DML-PSBP, DML-MTrisPC, TriML-P. TriML-35XL, TML-BP, TML-HQ, TML-pp-BPF, TML-BPA, TMOM-BP, HML-TPPHBA, HML-TPHAP (the above are trade names, manufactured by Honshu Chemical Industry Co., Ltd.), BIR-OC, BIP-PC, BIR-PC, BIR-PTBP, BIR-PCHP, BIP-BIOC-F, 4PC, BIR-BIPC-F, TEP-BIP-A, 46DMOC, 46DMOEP, TM-BIP-A (the above are trade names, manufactured by ASAHI YUKIZAI CORPORATION), MW-390, MW-100LM, MX-750LM, MX-270, MX-279, MX-280 (the above are trade names, manufactured by SANWA CHEMICAL CO.,LTD), 2,6-dimethoxymethyl-4- At least one of tert-butylphenol, 2,6-dimethoxymethyl-p-cresol, 2,6-diacetoxymethyl-p-cresol, naphthol, tetrahydroxyphenol, methyl gallate, bisphenol A, bisphenol E, methylene bisphenol, Bis-AP (trade names, manufactured by Honshu Chemical Industry Co., Ltd.), phenolic varnish resin, glycerol propoxylan, polyoxyethyl glycerol ether, pentaerythritol propoxylate, tripentaerythritol, di(trimethylolpropane) and 2-acrylate-(2-hydroxy-1,3-propylidene)di[oxy(2-hydroxy-3,1-propylidene)] ester.

[0048] In the aforementioned chemically amplified negative polyimide photoresist, the organic solvent may be at least one selected from N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), γ-butyrolactone (GBL), acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, tetrahydrofuran, dioxane, ethyl lactate, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and tert-butanol.

[0049] In the aforementioned chemically amplified negative polyimide photoresist, the photosensitizer may be naphthalene, anthracene, anthraquinone, fluoranthene, pyrene, etc. The photosensitizer may be a fluorene, perylene, curcumin, or coumarin derivative, specifically at least one of 9,10-diphenylanthracene, 9-anthracarbaldehyde, anthracene-9,10-dicarbaldehyde, 9,10-diethoxyanthracene, cassia seed extract, 9,10-bis(phenylethynyl)-2-ethylanthracene, 2-tert-butyl-9,10-bis(naphthyl-2-yl)anthracene, 9,10-dimethylanthracene, 9,10-bis(1-naphthyl)anthracene, 9,10-bis(2-naphthyl)anthracene, 9,10-dibutoxyanthracene, 2-ethylanthraquinone, and 2-isopropylthioxanthone; the mass ratio of the photosensitizer to the photoacid-producing agent may be 0.01 to 0.5:1, specifically 0.2:1;

[0050] The adhesion promoter may be γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidyl etheroxypropyltrimethoxysilane, γ-glycidyl etheroxypropyltriethoxysilane, 3-methacryloyloxypropyldimethoxymethylsilane, 3-methacryloyloxypropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-isocyanate-trimethoxysilane, 3-isocyanate-triethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, vinyltrimethoxysilane, N- The adhesive comprises at least one of the following: phenyl-3-aminopropyltrimethoxysilane, 3-(triethoxysilyl)propylsuccinic anhydride, N-(3-diethoxymethylsilylpropyl)succinimide, N-(3-diethoxymethylsilylpropyl)phthalic acid, benzophenone-3,3'-bis(N-[3-triethoxysilyl]propylamide)-4,4'-dicarboxylic acid, and phenyl-1,4-bis(N-[3-triethoxysilyl]propylamide)-2,5-dicarboxylic acid; the mass ratio of the adhesive to the polyimide precursor resin may be 0.5 to 25:100, specifically 3:100.

[0051] The thermal polymerization inhibitor may be at least one selected from hydroquinone, N-nitrosodiphenylamine, p-tert-butylcatechol, phenothiazine, N-phenylnaphthalene, ethylenediaminetetraacetic acid, 1,2-cyclohexanone diaminetetraacetic acid, glycol ether diaminetetraacetic acid, 2,6-di-tert-butyl-p-cresol, 5-nitroso-8-hydroxyquinoline, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 2-nitroso-5-(N-ethyl-N-sulfopropylamino)phenol, N-nitroso-N-phenylhydroxylamine ammonium salt, and N-nitroso-N(1-naphthyl)hydroxylamine ammonium salt; the mass ratio of the thermal polymerization inhibitor to the polyimide precursor resin may be 0.005 to 12:100, specifically 1:100;

[0052] The alkaline inhibitor may be a non-photosensitive alkaline inhibitor or a photosensitive alkaline inhibitor; the non-photosensitive alkaline inhibitor may be 2,6-dimethylpiperidine (DMP), N-hydroxyethylpiperidine, imidazole, pyrazole, or trioctylamine; the photosensitive alkaline inhibitor may be at least one of DNCDP, WPBG-300, WPBG-018, WPBG-027, WPBG-140, and WPBG-165 (the above are trade names, manufactured by Fujifilm); the mass ratio of the alkaline inhibitor to the photoacid generator may be 0 to 0.5:1, preferably 0.01 to 0.5:1, and specifically 0.4:1.

[0053] Secondly, the present invention provides a method for preparing the chemically amplified negative polyimide photoresist, comprising the following steps:

[0054] (1) The polyimide precursor solid resin was prepared according to the following steps:

[0055] 1) Under the action of an organic base, the aromatic tetracarboxylic dianhydride and the lower fatty alcohol undergo an esterification reaction in an organic solvent to obtain an organic solution containing the aromatic dianhydride diester;

[0056] 2) The thionyl chloride is added to the organic solution containing the aromatic diacid diester in step 1), and the aromatic diacid diester undergoes an acyl chloride reaction with the thionyl chloride to obtain an organic solution containing the aromatic diacid diester.

[0057] 3) Dissolve the aromatic diamine in an organic solvent to obtain an organic solution of the aromatic diamine; add the organic solution containing the aromatic diacyl chloride diester from step 2) to the organic solution of the aromatic diamine for polymerization reaction, and then add the end-capping agent for end-capping to obtain the polyimide precursor solid resin;

[0058] (2) Under yellow light and nitrogen protection, the polyimide precursor solid resin is dissolved in an organic solvent and stirred to form a homogeneous solution;

[0059] (2) Add the photoacid generator, the photocrosslinker, or the photoacid generator, the photocrosslinker and the functional additive to the homogeneous solution obtained in step (1), and stir to form a homogeneous solution to obtain the chemically amplified negative polyimide photoresist.

[0060] In the above preparation method, in step 1), the temperature of the esterification reaction can be 20-150℃, preferably 25-100℃, such as 25℃; the time of the esterification reaction can be 0.5-96h, preferably 0.5-24h, such as 6h; the organic base is selected from pyridine or its derivatives or triethylamine; the molar ratio of the organic base to the lower fatty alcohol can be 0.01-1:1, specifically 0.5:1; the organic solvent can be at least one selected from N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), γ-butyrolactone (GBL), acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, tetrahydrofuran, dioxane, ethyl lactate, ethylene glycol monomethyl ether, and ethylene glycol dimethyl ether.

[0061] In step 2), the temperature of the acyl chlorination reaction can be -30 to 50°C, preferably -20 to 25°C; the time of the acyl chlorination reaction can be 1 to 48 hours, preferably 2 to 12 hours; specifically, the acyl chlorination reaction can be carried out first at 0 to 10°C for 2 hours and then at 25°C for 4 hours.

[0062] In step 3), the organic solution containing aromatic diacyl chloride diester is added to the organic solution of aromatic diamine by dropwise addition; the temperature of the dropwise addition is -30 to 10°C, preferably -10 to 10°C, such as -10°C;

[0063] The polymerization reaction temperature can be 15–40°C, such as 25°C; the polymerization reaction time can be 0.5–96 h, preferably 1–24 h, such as 10 h; the end-capping temperature can be 15–40°C, such as 25°C; and the time can be 1–12 h, such as 1 h.

[0064] The method further includes, after the end-capping, the steps of pouring the reaction solution into deionized water, collecting the precipitated solid, and drying the solid.

[0065] Thirdly, the present invention provides the application of the chemically amplified negative polyimide photoresist in semiconductor chip manufacturing or advanced electronic packaging.

[0066] Specifically, the application involves fabricating interlayer dielectric insulating films, stress absorption-buffering protective films, passivation protective films, or alpha-particle shielding films on the surface of a chip to form multilayer interconnect circuits.

[0067] In a specific embodiment of the present invention, the chemically amplified negative polyimide photoresist is used to fabricate multilayer interconnect circuits on the surface of a silicon wafer. The method for fabricating multilayer interconnect circuits on the surface of a silicon wafer mainly includes the following steps: 1) Coating: The chemically amplified negative photosensitive polyimide resin photoresist is coated onto the wafer surface by spin coating and / or spray coating; 2) Pre-baking: Pre-baking at 60-150°C to form a photoresist film; 3) Exposure: Exposure using an ultraviolet light source through a photomask or photomask; 4) Post-baking: Post-baking at 100-170°C to complete the acid-catalyzed reaction; 5) Development + rinsing: The unexposed resin layer is dissolved and removed using a developer, leaving the exposed cross-linked cured resin layer; after rinsing, a precursor resin three-dimensional pattern is formed; 6) Heat curing: The precursor resin three-dimensional pattern on the silicon wafer surface is heat-cured and converted into a polyimide resin three-dimensional pattern. Using the above process, multilayer interconnect circuits can be formed on the surface of a silicon wafer.

[0068] The chemically amplified negative polyimide photoresist of this invention has advantages such as high photolithographic pattern resolution (≤15um), low curing pattern shrinkage (≤20%), high heat resistance (Tg≥320℃), excellent chemical corrosion resistance, and good adhesion to metal interfaces (peel strength≥70MPa), making it suitable for applications in semiconductor chip manufacturing, advanced packaging, flat panel displays, and other fields. Detailed Implementation

[0069] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, all materials and reagents used are commercially available.

[0070] The performance of the prepared negative CA-PSPI photoresist was evaluated using the following evaluation method:

[0071] 1) Photolithography process: A negative CA-PSPI photoresist solution is spin-coated onto the surface of a silicon wafer; a pre-baking treatment is performed at 60-150℃ to form a photoresist film; a mask is placed on the surface of the film, and exposure is performed using ultraviolet lamps (i and g lines); then a post-baking treatment is performed at 100-170℃ to complete the acid-catalyzed reaction; development is performed using cyclopentanone developer; after rinsing with propylene glycol methyl ether acetate, the film is cured in a nitrogen-protected oven (150℃ / 1h, 350℃ / 1h, 150℃ / 1h) to obtain a polyimide resin stereolithography pattern, and the minimum resolution is measured.

[0072] 2) Curing Shrinkage: A negative CA-PSPI photoresist solution was spin-coated onto the surface of a silicon wafer. A pre-baking treatment at 60-150℃ was performed to form a photoresist film. A mask was placed on the surface, and exposure was conducted using UV lamps (i and g lines). A post-baking treatment at 100-170℃ was then performed to complete the acid-catalyzed reaction. Development was performed using cyclopentanone developer, followed by rinsing with propylene glycol methyl ether acetate. The thickness D1 of the developed polyimide photolithographic pattern was measured. The patterned silicon wafer was then heated and cured in a nitrogen-protected oven (150℃ / 1h, 350℃ / 1h, 150℃ / 1h) at a heating rate of 5℃ per minute. After cooling to room temperature, the cured polyimide photolithographic pattern was obtained, and its cured thickness D2 was measured. The curing shrinkage rate was calculated as (1-D1 / D2).

[0073] 3) Heat Resistance: A negative CA-PSPI photoresist solution is spin-coated onto the surface of a silicon wafer; a pre-baking treatment is performed at 60-150℃ to form a photoresist film, followed by exposure with ultraviolet lamps (i and g lines), and then a post-baking treatment is performed at 100-170℃ to complete the acid-catalyzed reaction; the film is cured in a nitrogen-protected oven (150℃ / 1h, 350℃ / 1h, 150℃ / 1h), and the silicon wafer with the film is immersed in 47% HF for 5-10 minutes, then rinsed with water to obtain a polyimide film with a thickness of 5-7 μm; the polyimide film is cut into strips 4 mm wide and 14 mm long, and the glass transition temperature (tanδ peak value) of the film is tested using a dynamic thermomechanical analyzer (DMA). The DMA test frequency is 1 Hz, and the heating rate is 5℃ / min.

[0074] 4) Copper Adhesion: A negative CA-PSPI photoresist solution was spin-coated onto a silicon wafer surface sequentially sputtered with Ti (thickness: 200 nm) and Cu (thickness: 400 nm). A pre-baking treatment at 60-150°C was performed to form a photoresist film, followed by exposure with UV lamps (i and g lines), and then a post-baking treatment at 100-170°C to complete the acid-catalyzed reaction. The film was then cured in a nitrogen-protected oven (150°C / 1h, 350°C / 1h, 150°C / 1h) to obtain a 5-7 μm thick polyimide layer. The adhesion between the film and copper was tested using Quad Group's stud pull die bond strength test.

[0075] 5) Chemical resistance: The heat-cured polyimide photolithographic pattern was immersed in a caustic solution (1 wt.% potassium hydroxide + 39 wt.% 3-methoxy-3-methyl-1-butanol + 60 wt.% dimethyl sulfoxide (DMSO)) at 100°C for 1 hour. After washing with water and air drying, the chemical resistance of the polyimide film was evaluated by measuring the change in film thickness and observing under an optical microscope. If the change in the thickness of the polyimide film after immersion is within ±1% and no cracks or defects are produced, it is rated as 10 points. One point is deducted for every 1% increase in film thickness change.

[0076] The polyimide precursor resins used in the following examples were obtained through the following synthesis examples:

[0077] Synthesis Example 1: In a 500 ml three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 0.10 mol (31.02 g) of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (OPDA), 4.61 g of ethanol (EtOH), 3.96 g of pyridine, and 130 g of N-methylpyrrolidone (NMP) were added. The mixture was stirred at room temperature (25 °C) for 6 h to produce the corresponding diethyl aromatic diacid. The above product was reacted with 23.79 g of SOCl2 at 0-10 °C for 2 h, followed by a reaction at room temperature for 4 h to produce the corresponding ODPE diethyl diacid chloride.

[0078] In a 1L three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 0.1 mol (20.02) g of 4,4-diaminodiphenyl ether (4,4-ODA) and 158 g of NMP were added and stirred until dissolved to form a homogeneous transparent solution. The reaction solution was cooled to below 10°C using an ice bath. The ODPE-diethyl dichlorodimethyl ester prepared above was then added dropwise to the NMP solution of 4,4-diaminodiphenyl ether (4,4-ODA) over a period of 0.5 h. The reaction was then allowed to proceed at room temperature for 10 h. 1.48 g of phthalic anhydride was then added, and stirring was continued for 1 h. The reaction solution was poured into 5L of deionized water, and the solid precipitated was filtered, dried under vacuum, and primary polyamic acid ester resin (A-1) was obtained. This was then dissolved in tetrahydrofuran to form a solution. Residual metal or non-metal ions were removed by adsorption with anionic and cationic resins to obtain a high-purity polyimide precursor resin solid (also known as polymer A1: ODPC2-ODA). Mw: 22789g / mol

[0079] In Synthesis Example 2, 0.1 mol (29.42 g) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (BPDA) was used instead of 0.1 mol (31.02 g) of 3,3',4,4'-diphenyl ether tetracarboxylic acid dianhydride (OPDA) in Resin Synthesis Example 1 of the present invention. Otherwise, the reaction was carried out according to the method described in Resin Synthesis Example 1 of the present invention to obtain a high-purity polyimide precursor resin solid (also known as polymer A2: BPDC2-ODA). Mw: 25371 g / mol

[0080] In Synthesis Example 3, 0.1 mol (21.80 g) of pyromellitic dianhydride (PMDA) was used instead of 0.1 mol (31.02 g) of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (OPDA) in Resin Synthesis Example 1 of the present invention. Otherwise, the reaction was carried out according to the method described in Resin Synthesis Example 1 of the present invention to obtain a high-purity polyimide precursor resin solid (also known as polymer A3: PMDC2-ODA). Mw: 24923 g / mol

[0081] In Synthesis Example 4, 0.1 mol (32.22 g) of 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) was used instead of 0.1 mol (31.02 g) of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (OPDA) in Resin Synthesis Example 1 of the present invention. Otherwise, the reaction was carried out according to the method described in Resin Synthesis Example 1 of the present invention to obtain a high-purity polyimide precursor resin solid (also known as polymer A4: BTDC2-ODA, Mw: 23048 g / mol).

[0082] In Synthesis Example 5, 0.1 mol (44.42 g) of 3,3',4,4'-benzophenone tetracarboxylic dianhydride (6FDA) was used instead of 0.1 mol (31.02 g) of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (OPDA) in Resin Synthesis Example 1 of the present invention. Otherwise, the reaction was carried out according to the method described in Resin Synthesis Example 1 of the present invention to obtain a high-purity polyimide precursor resin solid (also known as polymer A5: 6FDC2-ODA). Mw: 27384 g / mol

[0083] In Synthesis Example 6, 0.1 mol (10.81 g) of p-phenylenediamine (PDA) was used instead of 0.1 mol (20.02 g) of 4,4-diaminodiphenyl ether (4,4-ODA) in Resin Synthesis Example 1 of the present invention. Otherwise, the reaction was carried out according to the method in Resin Synthesis Example 1 of the present invention to obtain a high-purity polyimide precursor resin solid (also known as polymer A6: ODPC2-PDA).

[0084] In Synthesis Example 7, 0.1 mol (29.23 g) of 1,2-bis(4-aminophenoxy)-benzene (1,3,4-APB) was used instead of 0.1 mol (20.02 g) of 4,4-diaminodiphenyl ether (4,4-ODA) in Resin Synthesis Example 1 of the present invention. Otherwise, the reaction was carried out according to the method described in Resin Synthesis Example 1 of the present invention to obtain a high-purity polyimide precursor resin solid (also known as polymer A7: ODPC2-1,3,4APB). Mw: 25923 g / mol

[0085] In Synthesis Example 8, 0.1 mol (23.02 g) of 2,2'-bis(trifluoromethyl)diaminobiphenyl (TFMB) was used instead of 0.1 mol (20.02 g) of 4,4-diaminodiphenyl ether (4,4-ODA) in Resin Synthesis Example 1 of the present invention. Otherwise, the reaction was carried out according to the method described in Resin Synthesis Example 1 of the present invention to obtain a high-purity polyimide precursor resin solid (also known as polymer A8: ODPC2-TFMB). Mw: 27384 g / mol

[0086] In Synthesis Example 9, 0.05 mol (14.71 g) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (BPDA) was used instead of 0.05 mol (15.51 g) of 3,3',4,4'-diphenyl ether tetracarboxylic acid dianhydride (OPDA) in Resin Synthesis Example 1 of the present invention, and 0.1 mol (10.81 g) of p-phenylenediamine (PDA) was used instead of 0.1 mol (20.02 g) of 4,4-diaminodiphenyl ether (4,4-ODA). Otherwise, the reaction was carried out according to the method in Resin Synthesis Example 1 of the present invention to obtain a high-purity polyimide precursor resin solid (also known as polymer A9: ODPC2-BPDC2-PDA). Mw: 23847 g / mol

[0087] In Synthesis Example 10, 0.05 mol (5.41 g) of p-phenylenediamine (PDA) was used instead of 0.05 mol (10.01 g) of 4,4-diaminodiphenyl ether (4,4-ODA) in Resin Synthesis Example 1 of the present invention. Otherwise, the reaction was carried out according to the method described in Resin Synthesis Example 1 of the present invention to obtain a high-purity polyimide precursor resin solid (also known as polymer A10: ODPC2-ODA-PDA). Mw: 25849 g / mol

[0088] Synthesis Example 11: In a 500 ml three-necked round-bottom flask equipped with a mechanical stirrer, thermometer, and nitrogen protection device, 0.10 mol (31.02 g) of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride (OPDA), 15.82 g of pyridine, and 129 g of N-methylpyrrolidone (NMP) were added. After 4 hours, 80 g of xylene was added, and the mixture was heated to 180 °C and stirred for 3 hours. After cooling, the reaction solution was poured into 5 L of deionized water, and the solid precipitated. The solid was filtered, dried under vacuum, and polyimide resin was obtained. This solution was then dissolved in tetrahydrofuran to form a solution. Residual metal or non-metal ions were removed by adsorption with anionic and cationic resins to obtain high-purity polyimide resin solid (also known as polymer B1: ODPA-ODA). Mw: 27837 g / mol

[0089] Synthesis Example 12: 26.03 g of 2-hydroxyethyl methacrylate (HEMA) was used instead of the 4.61 g of ethanol (EtOH) in Resin Synthesis Example 1 of the present invention. Otherwise, the reaction was carried out according to the method described in Resin Synthesis Example 1 of the present invention to obtain a high-purity polyimide precursor resin solid (also known as polymer C1: ODPA-HEMA-ODA). Mw: 25485 g / mol

[0090] Synthesis Example 13: 26.03 g of 2-hydroxyethyl methacrylate (HEMA) was used instead of the 4.61 g of ethanol (EtOH) in Resin Synthesis Example 2 of the present invention. Otherwise, the reaction was carried out according to the method in Resin Synthesis Example 1 of the present invention to obtain a high-purity polyimide precursor resin solid (also known as polymer C2: BPDA-HEMA-ODA). Mw: 24492 g / mol

[0091] Example 1: In a cleanroom equipped with a yellow light, 50g of polyimide precursor solid resin A1 was weighed and dissolved in 100g of NMP solvent (E) to form a homogeneous solution; then, 5g of [2-(propylsulfonyloxyimino)-2,3-dihydrothiophene-3-ylidene]-2-(2-methylphenyl)acetonitrile (PAG 103) and 10g of TML-BPA were added sequentially, and the mixture was stirred at room temperature for 1h to form a negative CA-PSPI photoresist solution with a solid content of 33±1% and a viscosity of 3500mPa.s at room temperature.

[0092] The aforementioned negative CA-PSPI photoresist solution was spin-coated onto the surface of a silicon wafer to form a liquid film with a thickness of 8 μm. After baking at 60-150°C for 3 min, a solid film was formed. A mask was placed on the solid film, and exposure was performed using ultraviolet lamps (i and g lines). Then, the film was baked at 100-170°C for 1-3 min. Developing was performed using cyclopentanone developer, followed by rinsing with propylene glycol methyl ether acetate to form a stereolithographic pattern. The pattern was then cured in a nitrogen-protected oven (150°C / 1 h + 350°C / 1 h) to obtain a stereolithographic pattern formed by a polyimide-cured film on the surface of the silicon wafer.

[0093] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 18µm, a curing pattern shrinkage rate of 13%, a curing PI film Tg of 320℃, a copper surface peel strength >60MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0094] Example 2: 1 g of 9,10-diphenylanthracene was added in addition to the method described in Example 1 of this invention.

[0095] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 13µm, a curing pattern shrinkage rate of 10%, a curing PI film Tg of 320℃, a copper surface peel strength >60MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0096] Example 3: 1.5g of γ-glycidoxypropyltrimethoxysilane was added in addition to the method described in Example 1 of this invention. Otherwise, the same method was used.

[0097] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 18µm, a curing pattern shrinkage rate of 13%, a curing PI film Tg of 320℃, a copper surface peel strength >70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0098] Example 4: 0.5g of N-nitrosodiphenylamine was added in addition to the method described in Example 1. Otherwise, the same method as described in Example 1 of this invention was used.

[0099] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 18µm, a curing pattern shrinkage rate of 13%, a curing PI film Tg of 320℃, a copper surface peel strength >60MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0100] Example 5: 1.5g of γ-glycidoxypropyltrimethoxysilane was added in addition to the method described in Example 2 of this invention. Otherwise, the same method was used.

[0101] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 13µm, a curing pattern shrinkage rate of 10%, a curing PI film Tg of 320℃, a copper surface peel strength >70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0102] Example 6: The amount of [2-(propylsulfonyloxyimino)-2,3-dihydrothiophene-3-ylidene]-2-(2-methylphenyl)acetonitrile (PAG 103) in Example 5 was reduced from 5g to 2.5g, and the amount of TML-BPA was reduced to 5g. Otherwise, the same method as described in Example 5 of this invention was used.

[0103] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 10µm, a curing pattern shrinkage rate of 15%, a curing PI film Tg of 320℃, a copper surface peel strength >60MPa, and a film thickness reduction of 2% in the chemical corrosion resistance test.

[0104] Example 7: The amount of [2-(propylsulfonyloxyimino)-2,3-dihydrothiophene-3-ylidene]-2-(2-methylphenyl)acetonitrile (PAG 103) in Example 5 was increased from 5g to 10g, and the amount of TML-BPA was increased to 20g. Otherwise, the same method as described in Example 5 of the present invention was used.

[0105] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 25µm, a curing pattern shrinkage rate of 7%, a curing PI film Tg of 320℃, a copper surface peel strength >70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0106] Example 8: 0.5g of N-nitrosodiphenylamine was added in addition to the method described in Example 5 of this invention.

[0107] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 13µm, a curing pattern shrinkage rate of 10%, a curing PI film Tg of 320℃, a copper surface peel strength >70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0108] Example 9: 5g of 2-[2-(4-methylbenzenesulfonyloxyimino)]-2,3-dihydrothiophene-3-ylidene]-2-(2-methylphenyl)acetonitrile (PAG121) was used instead of 5g of [2-(propylsulfonyloxyimino)-2,3-dihydrothiophene-3-ylidene]-2-(2-methylphenyl)acetonitrile (PAG 103) in Example 8, except that the procedure was the same as described in Example 8 of the present invention.

[0109] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 10µm, a curing pattern shrinkage rate of 16%, a curing PI film Tg of 320℃, a copper surface peel strength ≥60MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0110] Example 10: 2g of 2,6-dimethylpiperidine (DMP) was added in addition to the method described in Example 8 of this invention.

[0111] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 8µm, a curing pattern shrinkage rate of 17%, a curing PI film Tg of 320℃, a copper surface peel strength ≥60MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0112] Example 11: In Example 8, an additional 2g of diphenyliodonitrate was added, otherwise the same method as described in Example 8 of this invention was used.

[0113] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 8µm, a curing pattern shrinkage rate of 12%, a curing PI film Tg of 320℃, a copper surface peel strength ≥70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0114] Example 12: 50g of A2 resin from Synthesis Example 2 was used instead of A1 resin from Example 11, except that the same method as described in Example 11 of the present invention was used.

[0115] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 10µm, a curing pattern shrinkage rate of 10%, a curing PI film Tg of 340℃, a copper surface peel strength ≥70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0116] Example 13: 50g of A3 resin from Synthesis Example 3 was used instead of A1 resin from Example 11, except that the same method as described in Example 11 of the present invention was used.

[0117] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 13µm, a curing pattern shrinkage rate of 8%, a curing PI film Tg of 350℃, a copper surface peel strength ≥60MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0118] Example 14: 50g of A4 resin from Synthesis Example 4 was used instead of A1 resin from Example 11, except that the same method as described in Example 11 of the present invention was used.

[0119] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 8µm, a curing pattern shrinkage rate of 13%, a curing PI film Tg of 330℃, a copper surface peel strength ≥70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0120] Example 15: 50g of A5 resin from Synthesis Example 5 was used instead of A1 resin from Example 11, except that the same method as described in Example 11 of the present invention was used.

[0121] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 12µm, a curing pattern shrinkage rate of 12%, a curing PI film Tg of 350℃, a copper surface peel strength ≥70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0122] Example 16: 50g of A6 resin from Synthesis Example 6 was used instead of A1 resin from Example 11, except that the same method as described in Example 11 of the present invention was used.

[0123] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 13µm, a curing pattern shrinkage rate of 9%, a curing PI film Tg of 370℃, a copper surface peel strength ≥60MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0124] Example 17: 50g of A7 resin from Synthesis Example 7 was used instead of A1 resin from Example 11, except that the same method as described in Example 11 of the present invention was used.

[0125] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 10µm, a curing pattern shrinkage rate of 15%, a curing PI film Tg of 320℃, a copper surface peel strength ≥70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0126] Example 18: 50g of A8 resin from Synthesis Example 8 was used instead of A1 resin from Example 11, except that the same method as described in Example 11 of the present invention was used.

[0127] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 8µm, a curing pattern shrinkage rate of 13%, a curing PI film Tg of 350℃, a copper surface peel strength ≥60MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0128] Example 19: 50g of A9 resin from Synthesis Example 9 was used instead of A1 resin from Example 11, except that the same method as described in Example 11 of the present invention was used.

[0129] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 8µm, a curing pattern shrinkage rate of 12%, a curing PI film Tg of 340℃, a copper surface peel strength ≥70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0130] Example 20: 50g of A10 resin from Synthesis Example 10 was used instead of 50g of A1 resin from Example 11. Otherwise, the same method as described in Example 11 of the present invention was used.

[0131] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 10µm, a curing pattern shrinkage rate of 12%, a curing PI film Tg of 330℃, a copper surface peel strength ≥70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0132] Comparative Example

[0133] Comparative Example 1: 50g of B1 resin from Synthesis Example 11 was used instead of A1 resin from Example 11, except that the same method as described in Example 11 of the present invention was used.

[0134] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 10µm, a curing pattern shrinkage rate of 13%, a curing PI film Tg of 320℃, a copper surface peel strength ≤50MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0135] Comparative Example 2: 9g DML-PC was used instead of 9g TML-BPA in Comparative Example 1, except that the same method was used as described in Comparative Example 1 of this invention.

[0136] The negative CA-PSPI photoresist has a photolithographic pattern resolution of 8µm, a curing pattern shrinkage rate of 13%, a curing PI film Tg of 320℃, a copper surface peel strength ≤50MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0137] Comparative Example 3: In a cleanroom equipped with a yellow light, 50g of the polyimide precursor resin C1 prepared in Resin Synthesis Example 12 of the present invention was dissolved in 100g of NMP to form a homogeneous solution; then, 10g of ethylene glycol diethyl ether methacrylate (4EM), 1.0g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 1.5g of γ-glycidyl etheroxypropyltrimethoxysilane, and 0.5g of N-nitrosodiphenylamine were added sequentially, and the mixture was stirred at room temperature for 1h to form a negative PSPI photoresist solution containing methacrylate side chains.

[0138] The negative PSPI photoresist has a photolithographic pattern resolution of 10µm, a curing pattern shrinkage rate of 35%, a curing PI film Tg of 270℃, a copper surface peel strength ≥70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0139] Comparative Example 4: 50g of C2 resin from Synthesis Example 13 was used instead of B1 resin from Comparative Example 1. Otherwise, the same method as described in Comparative Example 1 of the present invention was used.

[0140] The negative PSPI photoresist has a photolithographic pattern resolution of 10µm, a curing pattern shrinkage rate of 37%, a curing PI film Tg of 290℃, a copper surface peel strength ≥70MPa, and no film thickness change and no cracks on the pattern surface during chemical corrosion resistance testing.

[0141] The performance comparison data of the photoresists prepared in the above embodiments and comparative examples are shown in Table 1.

[0142] Table 1. Performance of photoresists in examples and comparative examples

[0143]

[0144]

[0145] As can be seen, the negative CA-PSPI photoresist disclosed in this invention has better overall performance, including high resolution, low curing shrinkage, high heat resistance, high adhesion, and chemical corrosion resistance. Compared with PSPI prepared from fully imidized polyimide, the PSPI disclosed in this invention has higher adhesion; compared with PSPI prepared from polyamic acid esters containing methacrylate side chains, the PSPI disclosed in this invention has higher Tg and lower curing shrinkage. The negative CA-PSPI photoresist prepared by the method disclosed in this patent has excellent performance in all aspects, meeting the application requirements of circuits (ULSI) for redistribution layers (RDL), α-particle barriers, stress relief and buffer coatings, and interlayer dielectrics in multilayer metal interconnect circuits. It can also be used for substrate materials between chip stacking layers or for the fabrication of thick films such as walls in MEMS.

Claims

1. A chemically amplified negative polyimide photoresist, comprising a polyimide precursor solid resin, a photoacid generator, a photocrosslinking agent, a functional additive, and an organic solvent; wherein the functional additive is any one of the following: 1) a photosensitizer; 2) a photosensitizer and a adhesion promoter; 3) a photosensitizer and an inhibitor; 4) a photosensitizer, an adhesion promoter, and an inhibitor; wherein the inhibitor is a thermal polymerization inhibitor and / or an alkaline inhibitor; The polyimide precursor solid resin is made from aromatic diacyl chloride diester, aromatic diamine, and end-capping agent; the aromatic diacyl chloride diester is made from aromatic diacid diester and acyl chloride reagent; the aromatic diacid diester is made from aromatic tetracarboxylic dianhydride and lower fatty alcohol; The lower fatty alcohol is at least one of methanol, ethanol, propanol, isopropanol, n-butanol, and tert-butanol; The aromatic tetracarboxylic dianhydride is at least one selected from the following: pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride, 2,2-bis(3,4-phthalic anhydride)propane and 2,2-bis(3,4-phthalic anhydride)-1,1,1,3,3,3-hexafluoropropane; The aromatic diamine is at least one selected from p-phenylenediamine, 4,4-diaminodiphenyl ether, 3,4-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)-benzene, 2,2-bis(4-aminophenyl)propane, 2,2-bis[4-(4-aminophenoxy)phenyl)]propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl)]hexafluoropropane, 2,2'-bis(trifluoromethyl)diaminobiphenyl, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 1,3-bis(3-aminopropyl)tetraphenyldisiloxane, 1,3-bis(3-aminophenoxy)tetramethyldisiloxane, and 1,3-bis(4-aminophenoxy)tetramethyldisiloxane. The photosensitizer is at least one selected from 9,10-diphenylanthracene, 9-anthracene formaldehyde, anthracene-9,10-dicarboxaldehyde, 9,10-diethoxyanthracene, cassia seed extract, 9,10-bis(phenylethynyl)-2-ethylanthracene, 2-tert-butyl-9,10-bis(naphthyl-2-yl)anthracene, 9,10-dimethylanthracene, 9,10-bis(1-naphthyl)anthracene, 9,10-bis(2-naphthyl)anthracene, 9,10-dibutoxyanthracene, 2-ethylanthraquinone, and 2-isopropylthioxanthone.

2. The chemically amplified negative polyimide photoresist according to claim 1, characterized in that: The weight-average molecular weight of the polyimide precursor solid resin is 5000~100000 g / mol; The molar ratio of the aromatic diacyl chloride diester to the aromatic diamine is 1:0.8~1.2; The capping agent is at least one selected from phthalic anhydride, 3-methylphthalic anhydride, 4-methylphthalic anhydride, acetic anhydride, propionic anhydride, aniline, 3-methylaniline, 4-methylaniline, methylamine, ethylamine, and propylamine; The molar ratio of the aromatic diacid diester to the acyl chloride reagent is 1:1.5~3; The molar ratio of the aromatic tetracarboxylic dianhydride to the lower fatty alcohol is 1:1~4.

3. The chemically amplified negative polyimide photoresist according to any one of claims 1-2, characterized in that: The photoacid-generating agents are Irgacure PAG 103, Irgacure PAG 121, Irgacure PAG 169, Irgacure PAG250, Irgacure PAG290, diphenyliodonium hexafluorophosphate, tri-p-tolylsulfonium hexafluorophosphate, bis(3-methylphenyl)hexafluorophosphate, bis(4-tert-butylphenyl)iodonium hexafluorophosphate, 4,4'-xylyliodonium hexafluorophosphate, bis(4-tert-butylphenyl)hexafluorophosphate, (2-naphthyl)(2,4,6-trimethylphenyl)hexafluorophosphate, and (4-biphenyl)(2,4,6-trimethylphenyl)hexafluorophosphate. Iodine hexafluorophosphate, bis(3-methylphenyl) hexafluorophosphate, bis(2-methylphenyl) hexafluorophosphate, 4-octyloxydiphenyliodohexafluoroantimonate, diphenyliodonitrate, diphenyl(trifluoromethyl)sulfonium trifluoromethanesulfonate, tri-p-tolylsulfonium trifluoromethanesulfonate, (4-methoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, 1-naphthyldiphenylsulfonium trifluoromethanesulfonate, tris(4-tert-butylphenyl)sulfonium trifluoromethanesulfonate Salts, (4-phenoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, bis[4-(1,1-dimethylethyl)phenyl]iodonium trifluoromethanesulfonate, (2-tolyl)(2,4,6-trimethylphenyl)iodonium trifluoromethanesulfonate, phenyl(2,4,6-trimethoxyphenyl)iodonium p-toluenesulfonate, bis(4-tert-butylphenyl)iodonium p-toluenesulfonate, diphenyliodonium p-toluenesulfonate, N-hydroxy At least one of the following: naphthalimide trifluoromethanesulfonic acid, 2,4-bis(trichloromethyl)-6-p-methoxystyryl-S-triazine, N-hydroxy-5-norbornene-2,3-diamide nonafluorobutanesulfonic acid, perfluorobutylsulfonic acid triphenylsulfonium salt, bis(4-tert-butylphenyl)iodonium perfluoro-1-butanesulfonic acid, diphenyliodoacryl chloride, and a weak acid salt composed of iodonium salts, sulfonium salts, phosphonium salts, ammonium salts, or diazonium salts; and / or, The photocrosslinking agents are Bis-Z, BisP-EZ, TekP-4HBPA, TrisP-HAP, TrisP-PA, TrisP-SA, TrisOCR-PA, BisOCHP-Z, BisP-MZ, BisP-PZ, BisP-IPZ, BisOCP-IPZ, BisP-CP, BisRS-2P, BisRS-3P, BisP-OCHP, Methylene Tri-FR-CR, BisRS-26X, DML-MBPC, DML-MBOC, DML-OCHP, DML-PCHP, DML-PC, DML-PTBP, DML-34X, DML-EP, DML-POP, and Dihydroxymethyl-BisOC -P, DML-PFP, DML-PSBP, DML-MTrisPC, TriML-P, TriML-35XL, TML-BP, TML-HQ, TML-pp-BPF, TML-BPA, TMOM-BP, HML-TPPHBA, HML-TPHAP, BIR-OC, BIP-PC, BIR -PC, BIR-PTBP, BIR-PCHP, BIP-BIOC-F, 4PC, BIR-BIPC-F, TEP-BIP-A, 46DMOC, 46DMOEP, TM-BIP-A, MW-390, MW-100LM, MX-750LM,, MX-270, MX-279, MX-280, 2 At least one of the following: 6-dimethoxymethyl-4-tert-butylphenol, 2,6-dimethoxymethyl-p-cresol, 2,6-diacetoxymethyl-p-cresol, naphthol, tetrahydroxyphenol, methyl gallate, bisphenol A, bisphenol E, methylene bisphenol, Bis-AP, phenolic varnish resin, glycerol propoxylate, polyoxyethyl glycerol ether, pentaerythritol propoxylate, tripentaerythritol and di(trimethylolpropane), 2-acrylate-(2-hydroxy-1,3-propylene)di[oxy(2-hydroxy-3,1-propylene)] ester; and / or, The organic solvent is at least one selected from N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, tetrahydrofuran, dioxane, ethyl lactate, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and tert-butanol.

4. The chemically amplified negative polyimide photoresist according to any one of claims 1-2, characterized in that: The mass ratio of the photosensitizer to the photoacid-producing agent is 0.01~0.5:1; and / or, The adhesion promoter is γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidyl etheroxypropyltrimethoxysilane, γ-glycidyl etheroxypropyltriethoxysilane, 3-methacryloyloxypropyldimethoxymethylsilane, 3-methacryloyloxypropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-isocyanate-trimethoxysilane, 3-isocyanate-triethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, vinyltrimethoxysilane, N-phenyl-3- At least one of aminopropyltrimethoxysilane, 3-(triethoxysilyl)propylsuccinic anhydride, N-(3-diethoxymethylsilylpropyl)succinimide, N-(3-diethoxymethylsilylpropyl)phthalic acid, benzophenone-3,3'-bis(N-[3-triethoxysilyl]propylamide)-4,4'-dicarboxylic acid, and benzene-1,4-bis(N-[3-triethoxysilyl]propylamide)-2,5-dicarboxylic acid; the mass ratio of the adhesive to the polyimide precursor solid resin is 0.5~25:100; and / or, The thermal polymerization inhibitor is at least one selected from hydroquinone, N-nitrosodiphenylamine, p-tert-butylcatechol, phenothiazine, N-phenylnaphthylamine, ethylenediaminetetraacetic acid, 1,2-cyclohexanone diaminetetraacetic acid, glycol ether diaminetetraacetic acid, 2,6-di-tert-butyl-p-cresol, 5-nitroso-8-hydroxyquinoline, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 2-nitroso-5-(N-ethyl-N-sulfopropylamino)phenol, N-nitroso-N-phenylhydroxylamine ammonium salt, and N-nitroso-N(1-naphthyl)hydroxylamine ammonium salt; the mass ratio of the thermal polymerization inhibitor to the polyimide precursor solid resin is 0.005~12:100; and / or, The alkaline inhibitor is a non-photosensitive alkaline inhibitor or a photosensitive alkaline inhibitor; the non-photosensitive alkaline inhibitor is 2,6-dimethylpiperidine, N-hydroxyethylpiperidine, imidazole, pyrazole, or trioctylamine; the photosensitive alkaline inhibitor is at least one of DNCDP, WPBG-300, WPBG-018, WPBG-027, WPBG-140, and WPBG-165; the mass ratio of the alkaline inhibitor to the photoacid-producing agent is 0~0.5:

1.

5. The chemically amplified negative polyimide photoresist according to claim 4, characterized in that: The mass ratio of the alkaline inhibitor to the photoacid-producing agent is 0.01~0.5:

1.

6. A method for preparing the chemically amplified negative polyimide photoresist according to any one of claims 1-5, comprising the following steps: (1) The polyimide precursor solid resin was prepared according to the following steps: 1) Under the action of an organic base, the aromatic tetracarboxylic dianhydride and the lower fatty alcohol undergo an esterification reaction in an organic solvent to obtain an organic solution containing the aromatic dianhydride diester; 2) Add thionyl chloride to the organic solution containing the aromatic diacid diester in step 1), and the aromatic diacid diester undergoes an acyl chloride reaction with the thionyl chloride to obtain an organic solution containing the aromatic diacid diester. 3) Dissolve the aromatic diamine in an organic solvent to obtain an organic solution of the aromatic diamine; add the organic solution containing the aromatic diacyl chloride diester from step 2) to the organic solution of the aromatic diamine for polymerization reaction, and then add the end-capping agent for end-capping to obtain the polyimide precursor solid resin; (2) Under yellow light and nitrogen protection, the polyimide precursor solid resin prepared in step (1) is dissolved in an organic solvent and stirred to form a homogeneous solution; (3) Add the photoacid generator, the photocrosslinker and the functional additive to the homogeneous solution obtained in step (2), stir to form a homogeneous solution, and obtain the chemically amplified negative polyimide photoresist.

7. The preparation method according to claim 6, characterized in that: In step 1), the esterification reaction temperature is 20~150℃; the esterification reaction time is 0.5~96h; the organic base is selected from pyridine or its derivatives or triethylamine; the molar ratio of the organic base to the lower fatty alcohol is 0.01~1:1; the organic solvent is at least one selected from N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, tetrahydrofuran, dioxane, ethyl lactate, ethylene glycol monomethyl ether, and ethylene glycol dimethyl ether. In step 2), the temperature of the acyl chlorination reaction is -30~50℃; the time of the acyl chlorination reaction is 1~48h; In step 3), the polymerization reaction takes 0.5 to 96 hours; the end-capping temperature is 15 to 40°C and the time is 1 to 12 hours.

8. The preparation method according to claim 7, characterized in that: The esterification reaction is carried out at a temperature of 25~100℃.

9. The preparation method according to claim 7, characterized in that: The esterification reaction takes 0.5 to 24 hours.

10. The preparation method according to claim 7, characterized in that: The temperature for the acyl chloride reaction is -20 to 25°C.

11. The preparation method according to claim 7, characterized in that: The acyl chloride reaction takes 2 to 12 hours.

12. The preparation method according to claim 7, characterized in that: The polymerization reaction takes 1 to 24 hours.

13. The application of the chemically amplified negative polyimide photoresist according to any one of claims 1-5 in semiconductor chip manufacturing or advanced electronic packaging.

14. The application according to claim 13, characterized in that: Specifically, the application involves fabricating interlayer dielectric insulating films, stress absorption-buffering protective films, passivation protective films, or alpha-particle shielding films on the surface of a chip to form multilayer interconnect circuits.

Images