Positive photosensitive polyimide photoresist, polyimide film and application of positive photosensitive polyimide photoresist and polyimide film

Abstract

The invention relates to the field of polyimide materials, in particular to a positive photosensitive polyimide photoresist, a polyimide film and application of the positive photosensitive polyimide photoresist and the polyimide film. The positive photosensitive polyimide photoresist with excellent performance can be prepared by taking novel water-soluble polyamic acid ester with good dielectric property, low water absorption, heat resistance and the like as film-forming resin and combining the film-forming resin with the quinonediazide compound photosensitive component, the silane coupling agent and the organic solvent; the main film-forming component polyamic acid ester is a corresponding water-soluble polyimide precursor synthesized by using a series of simple and easily available polymeric monomers, and the realization of the water solubility is not limited to specific groups such as hydroxyl, carboxyl and the like in molecules. The photoresist has the advantages of high light sensitivity, high resolution, good thermal stability and chemical resistance, good heat and humidity resistance, good adhesion to various substrates and the like, an alkaline aqueous solution can be used as a developing solution, the loss of a film in a non-exposure area in the developing process is low due to low water absorption of the alkaline aqueous solution, and the developing time is short.

Description

Technical Field

[0001] The invention relates to the field of photosensitive polyimide photoresist materials, in particular to a positive photosensitive polyimide photoresist and a polyimide film and applications thereof. Background Art

[0002] Polyimide resins are a class of polymers containing imide rings in their backbones, exhibiting excellent high-temperature resistance, mechanical properties, insulation, and electrical properties. With the rapid development of the aerospace and electronics industries, this high-performance polymer material has seen rapid growth and is currently widely used in aerospace, microelectronics, nanotechnology, liquid crystals, separation membranes, lasers, and other fields. Applications include plastics, composites, films, adhesives, fibers, foams, liquid crystal alignment agents, separation membranes, and photoresists. Polyimide resins are considered "problem-solving experts," and it is widely acknowledged that "without polyimides, the microelectronics industry would not exist."

[0003] In the fields of integrated circuits and new displays, polyimide, as a functional photoresist material, can achieve insulation of chip input and output circuits, or serve as a segmentation material for display pixels.

[0004] For use as photoresists for insulating layers in integrated circuits, the photolithography process for polyimides requires a solution-based process. Using organic solvents or water-soluble polyimides or their precursors is essential, with water-soluble polyimides or their precursors being the preferred option from both an economic and environmental perspective. However, the polyimide resins used in currently studied photosensitive polyimide photoresists are essentially insoluble in water and can only be dissolved in organic solvents such as dimethylacetamide and dimethylformamide to form organic solvent-based polyimide resin solutions. Furthermore, organic solvent-based polyimide resin solutions, even at a solids content of 15%, can be highly viscous, requiring dilution with large amounts of organic solvents. Organic solvents are flammable, explosive, toxic, environmentally polluting, and harmful to human health, creating significant inconveniences in the storage, transportation, and use of organic solvent-based polyimide resin solutions. With increasing awareness of environmental health, rising organic solvent prices, and stricter environmental regulations on organic solvent use and waste discharge, the use of water-soluble resin solutions in place of organic solvent-based solutions has become a key trend in the chemical industry. However, the polyimide or its precursor used in the current photosensitive polyimide has the characteristic of being water-soluble. The structure of this water-soluble polyimide is mostly a polyimide that must contain hydroxyl and carboxyl structures in the molecule. These hydroxyl and carboxyl structures that achieve water solubility will always remain in the structure of the polyimide insulating layer, resulting in unfavorable performance factors such as high water absorption, high dielectric constant, and high dielectric loss. Therefore, these water-soluble polyimides are subject to certain restrictions in their molecular skeleton.

[0005] Positive-tone PSPI systems involve photoinduced polymer solubility increases in aqueous developer solutions. Positive-tone photosensitive polyimide photoresists are constructed based on the combination of a polymer soluble in aqueous developer solutions and a dissolution inhibitor. Prior art techniques include these soluble polyimides or their precursors, including polyamic acid, hydroxyl-containing polyamic acid esters, hydroxyl-containing polyimides, and carboxyl-containing polyimides. Dissolution inhibitors can be directly mixed or covalently bonded with these soluble polymers to control solubility. Currently, water-soluble positive-tone photoresists are limited to polyimide resin substrates containing hydroxyl or carboxyl groups within the molecule, limiting their applicability. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is a positive photosensitive polyimide photoresist and a polyimide film and their applications. The positive photosensitive polyimide photoresist provided by the present invention can use an alkaline aqueous solution as a developer to prepare a positive photoresist developing film, which has high photosensitivity, high resolution, good thermal stability and chemical resistance, good moisture and heat resistance, and good adhesion to various substrates.

[0007] The present invention provides a positive photosensitive polyimide photoresist, which comprises, in parts by mass:

[0008] 100 parts of polyamic acid ester;

[0009] 5-30 parts of quinone diazide compounds;

[0010] 0.5~10 parts of silane coupling agent;

[0011] 150-400 parts of organic solvent;

[0012] The positive photoresist provided by the present invention includes polyamic acid ester, which has a structure shown in Formula I:

[0013] Formula I;

[0014] Wherein, said n is 5~500;

[0015] The X is selected from substituted or unsubstituted C 12 ~C 30 Aryl or substituted or unsubstituted C 12 ~C 30 aryl;

[0016] The Ar1 is selected from substituted or unsubstituted C4~C 15 Cycloalkyl, substituted or unsubstituted C6~C 30 aryl;

[0017] The R is selected from substituted or unsubstituted C1~C 12 Alkyl or substituted or unsubstituted C6~C 12aromatic groups;

[0018] The Z is selected from substituted or unsubstituted alkyl groups with less than 12 carbon atoms or substituted or unsubstituted C6~C 12 aromatic groups;

[0019] The A is selected from a monobasic inorganic proton acid anion or an organic proton acid anion with a pKa of less than 5.

[0020] The polyamic acid ester described in the present invention is a water-soluble polyamic acid ester, which can achieve good water solubility without containing water-soluble groups such as hydroxyl groups and carboxyl groups in the molecule. It has a -ZN(R)2•HA side chain group, where • represents that HA and -ZN(R)2 are connected by an ionic bond. This group is derived from a fatty amine or aromatic amine containing a hydroxyl group. The water solubility of quaternary ammonium salts can be used to achieve water solubility of different substrates, rather than being limited to polyimides containing hydroxyl groups in the molecular structure. That is, the method has a wide range of substrate applications. The polyamic acid ester described in the present invention has neutral water solubility and solubility in alkaline aqueous solutions; the alkaline water solubility refers to an aqueous solution with a pH of 8 to 14. Specifically, the dissolution rate of the polyamic acid ester described in the present invention in neutral water solubility is >1.19 g / min; the dissolution rate of the polyamic acid ester in alkaline aqueous solutions is >2.19 g / min.

[0021] Specifically, the R is selected from substituted or unsubstituted C1~C 12 Alkyl or substituted or unsubstituted C6~C 12 The aryl group, wherein Z is selected from a substituted or unsubstituted alkyl group with less than 12 carbon atoms or a substituted or unsubstituted C6~C 12 The aromatic group, A is selected from a monobasic inorganic proton acid anion or an organic proton acid anion with a pKa of less than 5. Preferably, R is selected from a substituted or unsubstituted alkyl group with less than 8 carbon atoms or a substituted or unsubstituted C1-C8 aromatic group; more preferably, R is selected from a C1-C8 alkyl group; even more preferably, R is selected from a methyl group or an ethyl group. Preferably, Z is selected from a substituted or unsubstituted chain alkyl group with less than 12 carbon atoms or a substituted or unsubstituted C6-C 12 More preferably, the Z is selected from substituted or unsubstituted chain alkyl of less than 6 carbon atoms or substituted or unsubstituted phenyl; more preferably, the Z is selected from methyl or ethyl. Preferably, the A is selected from Cl - Br - , I - 、ClO4 - BrO4 - IO4 - 、NO3 - 、BF4 - PF4 - 、MeSO3 - or CF3SO3- More preferably, A is selected from Cl - Br - , I - 、NO3 - 、MeSO3 - or CF3SO3 - More preferably, A is selected from Cl - Br - or I - .

[0022] The polyamic acid ester of the present invention has an X group, which is derived from a diamine commonly used in the synthesis of polyimides. The diamine of the polyamic acid ester of the present invention can be selected from a conventional diamine for the synthesis of polyimides. The water solubility of the polyamic acid ester of the present invention does not vary due to the different diamine structures. Therefore, any conventional diamine for the synthesis of polyimides can be used as the diamine of the present invention. However, from the perspective of the performance requirements of the insulating layer of an integrated circuit, an aromatic diamine is preferred. Specifically, X is selected from substituted or unsubstituted C 12 ~C 30 Aryl.

[0023] Preferably, X is selected from the groups represented by the structures of formula X-1 to formula X-5;

[0024] .

[0025] More preferably, X is selected from the groups represented by the structures of formula Xa to formula Xh;

[0026] .

[0027] The polyamic acid ester of the present invention also has an Ar1 group, which is derived from an aliphatic dianhydride or an aromatic dianhydride. As the dianhydride of the polyamic acid ester of the present invention, a conventional dianhydride for synthesizing polyimides can be selected. The water solubility of the polyamic acid ester of the present invention does not cause a difference in water solubility due to the different dianhydride structures. Therefore, conventional dianhydrides for synthesizing polyimides can be used as the dianhydride of the present invention. However, from the perspective of performance requirements as an integrated circuit insulating layer, the Ar1 can be preferably selected from an aliphatic dianhydride or an aromatic dianhydride. It is further preferred that the Ar1 is a cyclic aliphatic group, a carbonyl-containing aromatic group, an ether-containing aromatic group, a sulfonyl-containing aromatic group, an ester-containing aromatic group, an alkyl-containing aromatic group, or an aromatic group containing only a benzene ring. Specifically, the Ar1 is selected from substituted or unsubstituted C4~C 15 Cycloalkyl or substituted or unsubstituted C6~C 30 Aryl.

[0028] More preferably, Ar1 is selected from the groups represented by the structures of formula Ar1-1 to formula Ar1-12;

[0029] .

[0030] More preferably, the Ar1 is selected from the groups represented by the structures of formula Ar1-a to formula Ar1-r;

[0031] .

[0032] The present invention can utilize a simple and rapid synthesis method to synthesize a variety of water-soluble polyamic acid esters with novel structures and diverse properties, which can be used to prepare the positive photosensitive polyimide photoresist. Specifically, the polyamic acid esters of the present invention are prepared by the following method: reacting a dianhydride having a structure of Formula 1 with an alcoholamine having a structure of Formula 2, then reacting the resulting reaction product with a diamine having a structure of Formula 3, and then adding a protonic acid HA for acidification to obtain the polyamic acid ester;

[0033] Formula 1; Formula 2; Formula 3.

[0034] The present invention further includes activating the reaction product before reacting it with a diamine having the structure of Formula 3. The activation described in the present invention refers to the method of activating the carboxyl group to achieve the reaction between the carboxyl group and the amine group. The activation method of the present invention specifically refers to adding an amide condensing agent formed by carboxylic acid and amine groups. For example, the amide condensing agent is selected from carbodiimide, carbonyldiimidazole, carbonium salt or organophosphorus condensing agent; preferably, the amide condensing agent is selected from carbodiimide or carbonyldiimidazole condensing agent; more preferably, the amide condensing agent is selected from dicyclohexylcarbodiimide (DCC), diisopropylcarbodiimide (DIC) or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI). Alternatively, the activation method of the present invention uses a conventional acyl halide reagent to convert the carboxyl group into an acyl halide. The acyl halide reagent can be thionyl halide, phosphorus halide, or carbonyl halide. The preferred compound is thionyl chloride (SOCl2), phosphorus oxychloride or oxalyl chloride.

[0035] Specifically, under a protective gas atmosphere, a dianhydride having a structure of formula 1 and an alcoholamine having a structure of formula 2 are reacted at 0°C~60°C for 5 h~7 h, and then the reaction product and an acyl halide reagent, or the reaction product and an amide condensation agent, are reacted at -5°C~5°C for 3 h~7 h, and then a diamine having a structure of formula 3 is added thereto and reacted at -5°C~5°C for 11 h~13 h, and then a protonic acid HA is added for acidification to obtain a polyamic acid ester.

[0036] More specifically, under a protective gas atmosphere, a dianhydride having a structure of formula 1 and an alcoholamine having a structure of formula 2 are reacted at 0°C~60°C for 5 h~7 h, and then the reaction product and SOCl2, or the reaction product and DCC, are reacted at -5°C~5°C for 3 h~7 h, and then a diamine having a structure of formula 3 is added thereto and reacted at -5°C~5°C for 11 h~13 h, and then a protonic acid HA is added for acidification to obtain a polyamic acid ester.

[0037] In certain embodiments of the present invention, under a protective gas atmosphere, a dianhydride having a structure of Formula 1 is dissolved in an organic solvent, an alcohol amine having a structure of Formula 2 is added thereto and the reaction is carried out at a temperature of 0°C to 60°C for 5 h to 7 h, and then SOCl2 is added to the reaction product, or DCC is added to the reaction product and the reaction is carried out at -5°C to 5°C for 3 h to 7 h, and then a diamine having a structure of Formula 3 is added and the reaction is carried out at -5°C to 5°C for 11 h to 13 h, and then protonic acid HA is added for acidification to obtain a red water-soluble polyamic acid ester solution, which can be precipitated with ethanol to obtain a light yellow water-soluble polyamic acid ester solid powder.

[0038] The molar ratio of the dianhydride having the structure of Formula 1, the alcoholamine having the structure of Formula 2, the diamine having the structure of Formula 3, and the protic acid HA of the present invention is (0.8-1.2): (1.6-2.4): 1: (2.0-3.0), for example, 0.8: (1.6-2.4): 1: (2.0-3.0), for example, 0.9: (1.6-2.4): 1, for example, 1.0: (1.6-2.4): 1: (2.0-3.0), for example, 1.1: (1.6-2.4): 1: (2.0-3.0), for example, 1.2: (1.6-2.4): 1: (2.0-3.0). The protective gas of the present invention is selected from one or more of nitrogen, helium, neon, and argon. The organic solvent of the present invention is not particularly limited, as long as it can dissolve the reaction materials, for example, it is selected from one or more of DMF, DMAc, NMP, and butyrolactone. The ratio of the amount of the amide condensation agent or acyl halide agent to the amount of the diamine having the structure of Formula 3 is (1.6-2.4):1.

[0039] The dianhydride having the structure of Formula 1 of the present invention is a dibasic acid anhydride, which is an essential component of the polymerization monomer of polyamic acid ester, and is specifically selected from 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-pyromellitic dianhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,3,2',3'-biphenyltetracarboxylic dianhydride, 3,4,3',4'-benzophenonetetracarboxylic dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, 3,4,3',4'-diphenyl ether tetracarboxylic dianhydride, 2, At least one of 3,3',4'-diphenylethertetracarboxylic dianhydride, 3,4,3',4'-diphenylsulfonetetracarboxylic dianhydride, 2,3,3',4'-diphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)phenyl dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)phenyl dianhydride, 3,4-dicarboxybenzoic acid-(3,4-dicarboxyphenol) ester dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, and 3,3',4,4'-benzophenonetetracarboxylic dianhydride. Preferably, the dianhydride having the structure of Formula 1 is selected from pyromellitic dianhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,3,2',3'-biphenyltetracarboxylic dianhydride, 3,4,3',4'-diphenyl ether tetracarboxylic dianhydride or 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride. More preferably, the dianhydride having the structure of Formula 1 is selected from 3,4,3',4'-diphenyl ether tetracarboxylic dianhydride or 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride.

[0040] The alcoholamine having the structure of Formula 2 described in the present invention is an essential component of the alcoholamine monomer in the esterification process. Preferably, the alcoholamine having the structure of Formula 2 is selected from at least one of dimethylaminoethanol, dimethylaminopropanol, dimethylaminopentanol, diethylaminopentanol, 4-dimethylaminophenol, and 2-diphenylaminoethanol; more preferably, the alcoholamine having the structure of Formula 2 is selected from at least one of dimethylaminoethanol, dimethylaminopropanol, dimethylaminopentanol, and diethylaminopentanol.

[0041] The diamine having the structure of Formula 3 of the present invention, as an essential component of the polymerization monomer of polyamic acid ester, is selected from a diamine containing a diphenyl ether group structure or a diamine containing a diphenyl sulfone group structure, specifically selected from at least one of 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-diaminodiphenyl sulfone, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 1,3-bis(4-aminophenoxy)biphenyl or 4,4'-bis(3-aminophenoxy)biphenyl. Preferably, the diamine having the structure of Formula 3 is selected from 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether or 4,4'-diaminodiphenyl ether. More preferably, the diamine having the structure of Formula 3 is selected from 3,4'-diaminodiphenyl ether or 4,4'-diaminodiphenyl ether.

[0042] The protonic acid HA of the present invention is selected from a monobasic inorganic protonic acid or an organic protonic acid with a pKa of less than 5. Preferably, the protonic acid HA of the present invention is selected from HCl, HBr, HI, HClO4, HBrO4, HIO4, HNO3, HBF4, HPF4, MeSO3H, or CF3SO3H. More preferably, the protonic acid HA is selected from HCl, HBr, HI, HNO3, MeSO3H, or CF3SO3H. Even more preferably, the protonic acid HA is selected from HCl, HBr, or HI.

[0043] The quinone diazide compound included in the positive photoresist of the present invention has the advantages of improving exposure sensitivity and the mechanical properties of the cured film. The quinone diazide compound of the present invention is selected from quinone diazide compounds with a molecular weight of 300 to 1500, preferably quinone diazide compounds with a molecular weight of 300 to 1200. A molecular weight of 300 or higher has the advantage of improving exposure sensitivity; a molecular weight of 1500 or lower has the advantage of improving the mechanical properties of the film after thermal curing.

[0044] In the present invention, depending on the exposure wavelength, the quinone diazide compound is preferably selected from one or more of a 4-naphthoquinone diazide sulfonyl ester compound, a 5-naphthoquinone diazide sulfonyl ester compound, a 4-naphthoquinone diazide sulfonyl naphthoquinone diazide sulfonyl ester compound, and a 5-naphthoquinone diazide sulfonyl naphthoquinone diazide sulfonyl ester compound. Among them, the 4-naphthoquinone diazide sulfonyl ester compound has absorption in the i-line region of a mercury lamp and is suitable for i-line exposure. The 5-naphthoquinone diazide sulfonyl ester compound has absorption extending into the g-line region of a mercury lamp and is suitable for g-line exposure.

[0045] The quinonediazide compounds described in the present invention can be synthesized using specific phenol compounds by the following methods. For example, there is a method in which 5-naphthoquinonediazidesulfonyl chloride is reacted with a phenol compound in the presence of triethylamine. Phenol compounds can also be synthesized by reacting an α-(hydroxyphenyl)styrene derivative with a polyphenol compound in the presence of an acid catalyst.

[0046] The positive photoresist of the present invention includes a silane coupling agent in an amount of 0.5 to 10 parts, preferably 1 to 10 parts. Because the alkoxysilyl groups of the silane coupling agent form bonds with hydroxyl groups on the substrate surface at temperatures above 150°C, a cured film with excellent adhesion to the substrate can be obtained through post-development heat treatment. Therefore, high adhesion between the cured film and the substrate can be ensured after high-temperature heat treatment above 300°C or heat treatment in air. The silane coupling agent of the present invention is selected from one or more of KH-560, KH-570, KH-580, and KH-590.

[0047] The organic solvent included in the positive photoresist of the present invention is not particularly limited, as long as it can dissolve the polyimide resin. Preferably, the organic solvent is an aprotic polar organic solvent. More preferably, the organic solvent is selected from one or more of dimethylformamide, dimethylacetamide, methylpyrrolidone, and tetrahydrofuran. The mass content of the organic solvent can be 150% to 400% of the mass content of the polyimide resin.

[0048] The positive photoresist of the present invention may further include a flame retardant, such as a phosphorus-containing flame retardant such as polyphosphoric acid, hypophosphite, phosphate ester, or phosphazene flame retardant. Specifically, the flame retardant may be selected from one or more of ammonium polyphosphate, diethylaluminum hypophosphite, triphenyl phosphate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and hexaphenoxycyclotriphosphazene. The amount of the phosphorus-containing flame retardant used is not particularly limited, but is generally about 1 to 30 parts by mass per 100 parts by mass of the polyamic acid ester.

[0049] The positive photoresist of the present invention may further include an inorganic filler. For example, magnesium hydroxide, aluminum hydroxide, silicon dioxide, silicon powder, graphite powder, magnesium carbonate, calcium carbonate, magnesium silicate, calcium silicate, magnesium oxide, calcium oxide, aluminum oxide, aluminum nitride, boron nitride, etc. The amount of the inorganic filler used is not particularly limited, and is generally about 1 to 30 parts by weight relative to 100 parts by weight of polyamic acid ester.

[0050] The positive photoresist provided by the present invention is a slurry made by mixing the aforementioned water-soluble polyamic acid ester as the main component, with a quinonediazide compound, a silane coupling agent and an organic solvent. Flame retardants, inorganic fillers, leveling agents, etc. can also be added or not as needed, and a positive, high-resolution water-soluble photoresist can be finally obtained.

[0051] The present invention provides a polyimide film obtained from the positive photosensitive polyimide photoresist described in any of the above technical solutions. Specifically, the polyimide film of the present invention is obtained by coating, exposing, developing, and thermally curing the positive photosensitive polyimide photoresist described in any of the above technical solutions on a substrate.

[0052] The polyimide film provided by the present invention is formed by thermally curing the polyamic acid ester component of the aforementioned positive photosensitive polyimide photoresist through an imidization process. The imide conversion temperature of the polyamic acid ester component is preferably a low-temperature imidization curing temperature of 200°C to 250°C. This is because the polyamic acid ester component in the photoresist of the present invention has a tertiary amine structure, which can act as a catalyst to achieve low-temperature imidization, which will facilitate the curing of the polyimide in temperature-sensitive environments.

[0053] The present invention utilizes the positive photosensitive polyimide photoresist described in any of the above technical solutions to sequentially coat, expose, develop, and thermally cure, wherein the thermal curing also serves as an imidization step, thereby enabling patterning of a polyimide film. The positive photosensitive polyimide photoresist provided by the present invention is fabricated into a positive photolithography developer film having advantages such as high photosensitivity, high photolithographic resolution, strong thermal stability, excellent mechanical properties, and good adhesion to various substrates.

[0054] The present invention also provides a method for preparing the above-mentioned polyimide film, comprising the following steps: coating the positive photosensitive polyimide photoresist described in any of the above technical solutions on a substrate, and then sequentially performing coating, exposure, development and thermal curing to obtain a polyimide film.

[0055] The present invention first coats the positive photosensitive polyimide photoresist described in any of the above technical solutions onto a substrate. The coating method is conventional photosensitive resin coating methods, such as spin coating, rod coating, blade coating, screen printing, and spraying. Preferably, spin coating or rod coating is used; more preferably, spin coating is used.

[0056] After coating, the present invention pre-bakes the positive photosensitive polyimide photoresist on the coated substrate. The pre-bake is a process of drying the solvent of the positive photosensitive polyimide photoresist coated on the substrate so that a dry resin layer is formed on the surface of the substrate; as drying methods, such as air drying, heating drying based on an oven or a hot plate, vacuum drying and the like. Drying can be carried out under conditions of 50°C to 140°C and 1 minute to 1 hour. Preferably, heating drying is carried out in an oven or a hot plate, and drying is carried out under conditions of 70°C to 140°C and 10 minutes to 1 hour; more preferably, heating drying is carried out in an oven, and drying is carried out under conditions of 120°C to 140°C and 30 minutes to 1 hour.

[0057] After prebaking, the present invention exposes the prebaked resin layer on the substrate. Specifically, an exposure apparatus such as a contact lithography machine, a projection exposure machine, or a stepper is used, with or without a patterned photomask or grating, and using an ultraviolet light source. Preferably, a contact lithography machine or a projection exposure machine is used as the exposure apparatus, and the dried resin layer is exposed using an ultraviolet light source with a patterned photomask. More preferably, a contact lithography machine is used, and the dried resin layer is exposed using an ultraviolet light source with a patterned photomask.

[0058] After exposure, the present invention develops the resin layer on the exposed substrate, and the unexposed portions of the exposed photosensitive resin layer are removed by development to form a patterned film on the substrate. As a development method for developing the exposed resin layer, a rotary spray method, an immersion method accompanied by ultrasonic treatment, and the like are selected. Preferably, the rotary spray method is selected for development. As the developer used in development, an alkaline aqueous solution can be used as the developer; specifically, the alkaline aqueous solution refers to an alkaline aqueous solution with a pH greater than 8. Preferably, at least one of a saturated sodium carbonate aqueous solution, a saturated sodium bicarbonate aqueous solution, 1% TMAH, 2.38% TMAH, or a 5% sodium hydroxide aqueous solution can be selected. More preferably, 1% TMAH or 2.38% TMAH is used as the developer; even more preferably, 2.38% TMAH is selected as the developer. The present invention is based on the excellent thermal stability of the polyamic acid ester in the positive photosensitive polyimide photoresist component, which results in less loss of the film in the non-exposed area during development and a short development time.

[0059] After development, the patterned film on the developed substrate is thermally cured. The thermal curing process heats the polyamic acid ester described herein to cause imidization, thereby converting it into polyimide, thereby forming a cured pattern. Simultaneously, the heating degrades and volatilizes the photosensitive components in the system. Thermal curing methods include those using a hot plate, an oven, or a programmable temperature-elevating oven. Preferably, a temperature-elevating oven is used. The maximum temperature for the thermal curing process is <250°C, and the thermal curing time is 30 minutes to 5 hours. The thermal curing atmosphere can be air or an inert gas such as nitrogen or argon. Preferably, the thermal curing temperature is between 200°C and 250°C, and the thermal curing time is between 1 hour and 5 hours. More preferably, the thermal curing temperature is between 230°C and 250°C, and the thermal curing time is between 3 hours and 5 hours.

[0060] The present invention also provides the use of the polyimide film described in any of the above technical solutions as an insulating layer, passivation layer, or interlayer dielectric layer in the semiconductor field. The polyimide film formed from the positive photosensitive polyimide photoresist provided by the present invention can be used for semiconductor passivation films, protective films for semiconductor components, interlayer insulating films for multi-layer wiring for high-density packaging, wiring protection insulating films for circuit boards, and electrode protection insulating films on substrates of display devices using organic electroluminescent elements.

[0061] The present invention provides a positive photosensitive polyimide photoresist and a polyimide film and their applications. Compared with the prior art, the present invention uses a new water-soluble polyamic acid ester with good dielectric properties, low hygroscopicity and other properties as the main raw material, combined with a quinonediazide compound, a silane coupling agent and an organic solvent to prepare a positive polyimide photoresist with excellent performance. The main raw material polyamic acid ester can be synthesized from a series of simple and easily available polymerization monomers to form the corresponding water-soluble polyimide, which is not limited to monomers with water-soluble groups such as hydroxyl and carboxyl groups in the molecule. The preparation process is simple, the cost is low, and it meets the current requirements for environmental protection. The positive photoresist described in the present invention has the advantages of high photosensitivity, high resolution, good thermal stability and chemical resistance, good moisture and heat resistance, and good adhesion to various substrates. Its excellent thermal stability reduces the loss of the film in the non-exposed area during the development process and shortens the development time. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a flow chart for preparing the water-soluble polyamic acid ester and polyimide of the present invention;

[0063] Figure 2 is a micrograph of the patterned film obtained in Example 1;

[0064] Figure 3is a micrograph of the patterned film obtained in Example 2;

[0065] Figure 4 is a micrograph of the patterned film obtained in Example 3;

[0066] Figure 5 is a micrograph of the patterned film obtained in Example 4;

[0067] Figure 6 is a micrograph of the patterned film obtained in Example 5;

[0068] Figure 7 is a micrograph of the patterned film obtained in Example 6;

[0069] Figure 8 is a micrograph of the patterned film obtained in Example 7;

[0070] Figure 9 is a micrograph of the patterned film obtained in Example 8;

[0071] Figure 10 is a micrograph of the patterned film obtained in Example 9;

[0072] Figure 11 is a micrograph of the patterned film obtained in Example 10;

[0073] Figure 12 is a micrograph of the patterned film obtained in Comparative Example 1;

[0074] Figure 13 is a micrograph of the patterned film obtained in Comparative Example 2;

[0075] Figure 14 is a micrograph of the patterned film obtained in Comparative Example 3;

[0076] Figure 15 This is a micrograph of the patterned film obtained in Comparative Example 4. DETAILED DESCRIPTION

[0077] The present invention discloses a positive photosensitive polyimide photoresist and a polyimide film and their applications. Those skilled in the art can refer to the contents of this document and appropriately improve the process parameters to achieve the same. It should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0078] The present invention first prepares a water-soluble polyamic acid ester, and then formulates the obtained water-soluble polyamic acid ester into a composition slurry of the positive photoresist of the present invention, which is coated on a substrate, pre-baked and photolithographically processed, and then cured at 250°C to obtain a polyimide film. Figure 1 As shown, Figure 1 This is a flow chart for the preparation of the water-soluble polyamic acid ester and polyimide of the present invention.

[0079] The present invention will be further described below with reference to the embodiments:

[0080] Example 1

[0081] 4,4'-Oxydiphthalic anhydride (ODPA) (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminoethanol (322.2 mol, 28.7 g) were added to the reaction vessel in sequence and stirred at 0°C for 6 h. Dichlorothionyl (SOCl2) (322.2 mmol, 38.0 g) was added to the bottle and stirred at 0°C for 3 h. 4,4'-diaminodiphenyl ether (ODA) (161.1 mmol, 32.2 g) was added and stirred at 0°C for 12 h. A saturated HCl solution was then added. (322.2 mmol, 22.9 mL), and the obtained polyamic acid ester solution was precipitated with ethanol to obtain yellow polyamic acid ester powder.

[0082] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-560 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0083] Example 2

[0084] Pyromellitic dianhydride (PMDA) (161.1 mol, 35.1 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminoethanol (322.2 mol, 28.7 g) were added to a reaction vessel in sequence and stirred at 0°C for 6 h. DCC (322.2 mmol, 66.5 g) was added to the bottle and stirred at -5°C for 4 h. 4,4'-diaminodiphenyl ether (ODA) (161.1 mmol, 32.2 g) was stirred at 0°C for 11 h. A saturated HBr solution (322.2 mmol, 38.0 g) was added, and the resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0085] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-570 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0086] Example 3

[0087] 3,3',4,4'-Benzophenonetetracarboxylic dianhydride BTDA (161.1 mol, 51.9 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminoethanol (322.2 mol, 28.7 g) were added to the reaction vessel in sequence and stirred at -5 °C for 6 h. Thionyl chloride SOCl2 (322.2 mmol, 38.0 g) was added to the bottle and stirred at 5 °C for 7 h. 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g), 5 The mixture was stirred at ℃ for 13 h, and HI (322.2 mmol, 41.2 g) was added. The obtained polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0088] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-580 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0089] Example 4

[0090] 4,4'-Oxydiphthalic anhydride (ODPA) (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminoethanol (322.2 mol, 28.7 g) were added to a reaction vessel in sequence and stirred at 5°C for 7 h. DCC (322.2 mmol, 66.5 g) was added to the bottle and stirred at -5°C for 6 h. 4,4'-Diaminodiphenylsulfone (DDS) (161.1 mmol, 40.0 g) was stirred at -5°C for 11 h. HI (322.2 mmol, 41.2 g) was added and the resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0091] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-580 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0092] Example 5

[0093] 4,4'-Oxydiphthalic anhydride (ODPA) (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminoethanol (322.2 mol, 28.7 g) were added to a reaction vessel in sequence and stirred at 3°C for 7 hours. Thionyl chloride (SOCl2) (322.2 mmol, 38.0 g) was added to the bottle and stirred at 3°C for 5 hours. 1,4-Cyclohexanediamine (CHDA) (161.1 mmol, 18.4 g) was stirred at 5°C for 13 hours. HClO4 (322.2 mmol, 32.4 g) was added, and the resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0094] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-570 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0095] Example 6

[0096] 4,4'-Oxydiphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), dimethylaminopropanol (322.2 mol, 33.2 g) were added to the reaction vessel in sequence and stirred at 60 °C for 7 h. DCC was added to the bottle. (322.2 mmol, 66.5 g), stirred at 0 ° C for 3 h, 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g), stirred at -5 ° C for 11 h, HBrO4 (322.2 mmol, 46.7 g) was added, and the obtained polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0097] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-590 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0098] Example 7

[0099] 4,4'-Oxydiphthalic anhydride (ODPA) (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and dimethylaminopentanol (322.2 mol, 41.2 g) were added to a reaction vessel in sequence and stirred at 45°C for 6 h. Thionyl chloride (SOCl2) (322.2 mmol, 38.0 g) was added to the bottle and stirred at 5°C for 7 h. 4,4'-Diaminodiphenyl ether (ODA) (161.1 mmol, 32.2 g) was stirred at -5°C for 13 h. HBF4 (322.2 mmol, 28.3 g) was added, and the resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0100] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-560 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0101] Example 8

[0102] 4,4'-Oxydiphthalic anhydride (ODPA) (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and diethylaminopentanol (322.2 mol, 49.9 g) were added to a reaction vessel in sequence and stirred at 0°C for 6 h. DCC (322.2 mmol, 66.5 g) was added to the bottle and stirred at 0°C for 3 h. 4,4'-Diaminodiphenyl ether (ODA) (161.1 mmol, 32.2 g) was stirred at 0°C for 12 h. MeSO3H (322.2 mmol, 30.9 g) was added, and the resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0103] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them, add DNQ (1 g) and silane coupling agent KH-560 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0104] Example 9

[0105] 4,4'-Oxydiphthalic anhydride (ODPA) (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and 4-dimethylaminophenol (322.2 mol, 44.1 g) were added to a reaction vessel in sequence and stirred at 55°C for 6 h. Thionyl chloride (SOCl2) (322.2 mmol, 38.0 g) was added to the bottle and stirred at 0°C for 7 h. 4,4'-Diaminodiphenyl ether (ODA) (161.1 mmol, 32.2 g) was stirred at 0°C for 12 h. HNO3 (322.2 mmol, 20.3 g) was added, and the resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0106] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-560 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0107] Example 10

[0108] 4,4'-Oxydiphthalic anhydride (ODPA) (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and 2-diphenylaminoethanol (322.2 mol, 68.6 g) were added to a reaction vessel in sequence and stirred at 0°C for 6 h. Dicyclohexylcarbodiimide (DCC) (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether (ODA) (161.1 mmol, 32.2 g) were added to the bottle and stirred at 0°C for 12 h. HPF6 (322.2 mmol, 47.0 g) was added, and the resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0109] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-560 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0110] Comparative Example 1

[0111] 4,4'-Oxydiphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and 4-diphenylaminophenol (322.2 mol, 84.0 g) were added to the reaction vessel in sequence and stirred at 0°C for 6 h. Dicyclohexylcarbodiimide DCC (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) were added to the bottle and stirred at 0°C for 12 h. Saturated HCl solution was then added. (322.2 mmol, 22.9 mL), and the obtained polyamic acid ester solution was precipitated with ethanol to obtain yellow polyamic acid ester powder.

[0112] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-560 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0113] Comparative Example 2

[0114] 4,4'-Oxydiphthalic anhydride ODPA (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and 2-diphenylaminomethanol (322.2 mol, 55.8 g) were added to the reaction vessel in sequence and stirred at 0°C for 6 h. Dicyclohexylcarbodiimide DCC (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether ODA (161.1 mmol, 32.2 g) were added to the bottle and stirred at 0°C for 12 h. Saturated HCl solution was then added. (322.2 mmol, 22.9 mL), and the obtained polyamic acid ester solution was precipitated with ethanol to obtain yellow polyamic acid ester powder.

[0115] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-560 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0116] Comparative Example 3

[0117] 4,4'-Oxydiphthalic anhydride (ODPA) (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and diethanolamine (322.2 mol, 33.8 g) were added to the reaction vessel in sequence and stirred at 0°C for 6 h. Dicyclohexylcarbodiimide (DCC) (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether (ODA) (161.1 mmol, 32.2 g) were added to the bottle and stirred at 0°C for 12 h. Saturated HBr solution (322.2 mmol, 38.0 g) was then added.

[0118] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-560 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0119] Comparative Example 4

[0120] 4,4'-Oxydiphthalic anhydride (ODPA) (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and triethanolamine (322.2 mol, 48.0 g) were added to a reaction vessel in sequence and stirred at 0°C for 6 h. Dicyclohexylcarbodiimide (DCC) (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether (ODA) (161.1 mmol, 32.2 g) were added to the bottle and stirred at 0°C for 12 h. Saturated HBr solution (322.2 mmol, 38.0 g) was added, and the resulting polyamic acid ester solution was precipitated with ethanol to obtain a yellow polyamic acid ester powder.

[0121] Take polyamic acid ester A (10 g) and DMF (40 g), stir and dissolve them. Add DNQ (1 g) and silane coupling agent KH-560 (0.8 g) to obtain a positive photosensitive polyimide photoresist solution.

[0122] Comparative Example 5

[0123] 4,4'-Oxydiphthalic anhydride (ODPA) (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and ethanolamine (322.2 mol, 19.6 g) were added to a reaction vessel in sequence and stirred at 0°C for 6 h. Dicyclohexylcarbodiimide (DCC) (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether (ODA) (161.1 mmol, 32.2 g) were added to the bottle and stirred at 0°C for 12 h. HI (322.2 mmol, 41.2 g) was added, and the resulting polyamic acid ester solution was precipitated with ethanol, but no yellow polyamic acid ester powder was obtained.

[0124] Comparative Example 6

[0125] 4,4'-Oxydiphthalic anhydride (ODPA) (161.1 mol, 50.0 g), DMF (184 g), pyridine (322.2 mmol, 25.5 g), and N-methyl-2-hydroxyethylamine (322.2 mol, 24.2 g) were added to a reaction vessel in sequence and stirred at 0°C for 6 h. Dicyclohexylcarbodiimide (DCC) (322.2 mmol, 66.4 g) and 4,4'-diaminodiphenyl ether (ODA) (161.1 mmol, 32.2 g) were added to the bottle and stirred at 0°C for 12 h. HI (322.2 mmol, 41.2 g) was added, and the resulting polyamic acid ester solution was precipitated with ethanol, but no yellow polyamic acid ester powder was obtained.

[0126] Performance testing:

[0127] The prepared water-soluble polyamic acid ester was subjected to aqueous solution solubility test, alkaline solution solubility test, and weight average molecular weight test, and the polyimide composition slurry was evaluated for photolithography level, as follows:

[0128] (1) Solubility in aqueous solution: Water was continuously added to the polyamic acid esters prepared in Examples and Comparative Examples until they were completely dissolved, and their dissolution rates were tested.

[0129] (2) Alkaline solution solubility: Alkaline solution was continuously added to the polyamic acid esters prepared in the examples and comparative examples until they were completely dissolved, and their dissolution rates were tested.

[0130] (3) Determination of weight-average molecular weight: Gel permeation chromatography (PL-GPC120, Polymer Laboratories, UK) was used for testing.

[0131] (4) Lithography level evaluation process:

[0132] 1. Coating: Spin-coat the polyimide photoresist solution onto the silicon substrate.

[0133] 2. Pre-baking: Heat and dry the silicon wafer on a hot plate at 100°C for 10 minutes.

[0134] 3. Exposure: Use a projection exposure machine, a photomask with a pattern, and a UV light source to expose the dried resin layer. The exposure intensity is 200 mJ / cm 2 .

[0135] 4. Development: Using 2.38% TMAH as the developer, the patterned film was developed by the rotary spray method.

[0136] 5. Curing: Curing the above patterned film at 250 o C to obtain a cured polyimide film.

[0137] The following performance tests were performed on the cured polyimide film:

[0138] (1) Determination of dielectric constant and dielectric loss: The polyimide film was fixed in a separated dielectric resonator (SPDR), and the dielectric constant and dielectric loss tangent at 10 GHz were measured using a vector network analyzer (N5244A, Agilent Technologies).

[0139] (2) Adhesion and peeling strength test: The obtained polyimide film was tested for its peeling strength (N / cm) at 90° stretching using a tensile testing machine.

[0140] (3) Determination of glass transition temperature: static thermomechanical analyzer (TMA Q400), the test atmosphere is nitrogen, the heating rate is 5 ℃ / min, and the temperature range is 20 ℃~800 ℃.

[0141] The patterned film was observed microscopically, and the micrograph of the patterned film obtained above is as follows: Figures 2 to 15 As shown. Among them, Figure 2 is a micrograph of the patterned film obtained in Example 1; Figure 3 is a micrograph of the patterned film obtained in Example 2; Figure 4 is a micrograph of the patterned film obtained in Example 3; Figure 5 is a micrograph of the patterned film obtained in Example 4; Figure 6 is a micrograph of the patterned film obtained in Example 5; Figure 7 is a micrograph of the patterned film obtained in Example 6; Figure 8 is a micrograph of the patterned film obtained in Example 7; Figure 9is a micrograph of the patterned film obtained in Example 8; Figure 10 is a micrograph of the patterned film obtained in Example 9; Figure 11 is a micrograph of the patterned film obtained in Example 10; Figure 12 is a micrograph of the patterned film obtained in Comparative Example 1; Figure 13 is a micrograph of the patterned film obtained in Comparative Example 2; Figure 14 is a micrograph of the patterned film obtained in Comparative Example 3; Figure 15 This is a micrograph of the patterned film obtained in Comparative Example 4.

[0142] The solubility, weight average molecular weight, photolithography level evaluation of the pre-baked polyamic acid ester obtained above, and the dielectric properties, adhesiveness and thermal properties test results of the cured polyimide film are shown in Tables 1, 2 and 3:

[0143] Table 1

[0144]

[0145] As shown in Table 1, Table 1 shows the dissolution rates of the polyamide esters in Examples 1-10 and Comparative Examples 1-6 in aqueous solutions and alkaline solutions, respectively. The polyamide esters in the Examples had dissolution rates >1.19 g / min in aqueous solutions and >2.19 g / min in alkaline solutions. The polyamide esters in the Comparative Examples, on the other hand, had poor solubility in both aqueous and alkaline solutions.

[0146] Table 2

[0147]

[0148] Table 2 compares the weight-average molecular weight of the polyamic acid esters in Examples 1-10 and Comparative Examples 1-6, and the lithographic resolution of the patterned films prepared therefrom. While Examples 1-10 achieve lithographic resolutions of 1-2 μm, Comparative Examples 1-6 achieve resolutions of only 10 μm or even no pattern at all. Furthermore, the overall molecular weight of the films in the Comparative Examples is significantly lower than that in the Examples.

[0149] Table 3

[0150]

[0151] As shown in Table 3, Table 3 shows the adhesive and thermal properties of the cured polyimide films prepared in Examples 1 to 10 and Comparative Examples 1 to 6, as well as the dielectric properties at a frequency of 10 GHz. Examples 1 to 10 all have good dielectric properties and good adhesive properties; while the dielectric properties, thermal properties, and adhesive properties of the comparative examples are all poor.

[0152] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A positive photosensitive polyimide photoresist, characterized in that: In parts by mass, including: 100 parts of polyamic acid ester; 5-30 parts of quinone diazide compounds; 0.5~10 parts of silane coupling agent; 150-400 parts of organic solvent; The polyamic acid ester has a structure shown in Formula I: Formula I; Wherein, said n is 5~500; The X is selected from substituted or unsubstituted C 12 ~C 30 aryl; The Ar1 is selected from substituted or unsubstituted C4~C 15 Cycloalkyl or substituted or unsubstituted C6~C 30 aryl; The R is selected from substituted or unsubstituted C1~C 12 Alkyl or substituted or unsubstituted C6~C 12 aromatic groups; The Z is selected from substituted or unsubstituted alkyl groups with less than 12 carbon atoms or substituted or unsubstituted C6~C 12 aromatic groups; The A is selected from a monobasic inorganic proton acid anion or an organic proton acid anion with a pKa of less than 5.

2. The positive photosensitive polyimide photoresist according to claim 1, characterized in that In Formula I, R is selected from a substituted or unsubstituted alkyl group with less than 8 carbon atoms or a substituted or unsubstituted C1-C8 aryl group; The Z is selected from substituted or unsubstituted chain alkyl with less than 12 carbon atoms or substituted or unsubstituted C6~C 12 of aromatic groups.

3. The positive photosensitive polyimide photoresist according to claim 1, characterized in that: In formula I, A is selected from Cl - Br - , I - 、ClO4 - BrO4 - IO4 - 、NO3 - 、BF4 - PF4 - 、MeSO3 - or CF3SO3 - .

4. The positive photosensitive polyimide photoresist according to claim 1, characterized in that In Formula I, X is selected from the groups represented by the structures of Formulas X-1 to X-5; ； Ar1 is selected from the groups represented by the structures of formula Ar1-1 to formula Ar1-12; 。 5. The positive photosensitive polyimide photoresist according to claim 1, characterized in that: The polyamic acid ester is prepared by the following method: A dianhydride having a structure of Formula 1 and an alcoholamine having a structure of Formula 2 are reacted, and then the reaction product is reacted with a diamine having a structure of Formula 3, and then a protonic acid HA is added for acidification to obtain a polyamic acid ester; Formula 1; Formula 2; Formula 3.

6. The positive photosensitive polyimide photoresist according to claim 5, characterized in that: The molar ratio of the dianhydride having the structure of formula 1, the alcoholamine having the structure of formula 2, the diamine having the structure of formula 3 and the protonic acid HA is (0.8-1.2): (1.6-2.4): 1: (2.0-3.0).

7. The positive photosensitive polyamic acid ester photoresist according to claim 1, characterized in that: The dissolution rate of the polyamic acid ester in a neutral aqueous solution is greater than 1.19 g / min; and the dissolution rate of the polyamic acid ester in an alkaline aqueous solution is greater than 2.19 g / min.

8. The positive photosensitive polyimide photoresist according to claim 1, characterized in that: The quinone diazide compound is selected from quinone diazide compounds with a molecular weight of 300 to 1500, and the quinone diazide compound is selected from one or more of a 4-naphthoquinone diazide sulfonyl ester compound, a 5-naphthoquinone diazide sulfonyl ester compound, a 4-naphthoquinone diazide sulfonyl naphthoquinone diazide sulfonyl ester compound, and a 5-naphthoquinone diazide sulfonyl naphthoquinone diazide sulfonyl ester compound; The silane coupling agent is selected from one or more of KH-560, KH-570, KH-580, and KH-590.

9. A polyimide film, characterized in that: The positive photosensitive polyimide photoresist according to any one of claims 1 to 8 is coated on a substrate, exposed, developed and thermally cured in sequence; the thermal curing temperature is 200° C. to 250° C.

10. Use of the polyimide film according to claim 9 as an insulating layer, passivation layer or interlayer dielectric layer in the semiconductor field.

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