A photosensitive polyimide resin, a polyimide composition, and a method for preparing the same

Abstract

The application discloses a photosensitive polyimide resin, a polyimide composition and a preparation method thereof. The photosensitive polyimide resin has a molecular structure as shown in formula (1). The aminoized hyperbranched polysiloxane unit with hydrophobic characteristics is introduced into the polyimide molecular main chain to form a micro-crosslinking structure between the molecular chains, and the crosslinking reaction of the photosensitive unit effectively improves the resolution of the photoresist and reduces the thermal expansion coefficient of the patterned film. The rich Si-O-Si units in the hyperbranched polysiloxane and the low polarity and hydrophobic characteristics of the CF3 unit can reduce the dielectric constant of the patterned film. The Si-O-Si network unit has better interface compatibility with glass and a silicon wafer, thereby forming stronger interface force and improving the adhesion between the photoresist and the substrate.

Description

Technical Field

[0001] This invention belongs to the field of photoresist materials technology, and specifically relates to a photosensitive polyimide resin, a polyimide composition and its preparation method. Background Technology

[0002] Photosensitive polyimide (PSPI) is a type of polyimide that is highly sensitive to ultraviolet light, X-rays, electron beams, or ion beams and can undergo photochemical reactions. When PSPI is used as a photoresist, a photochemical reaction occurs in the exposed area, resulting in a significant difference in the solubility of PSPI in the developer between the exposed and non-exposed areas. After development, a photolithographic pattern is formed. Compared to traditional photoresists, PSPI photoresist directly forms the dielectric insulating layer required for devices after photolithographic patterning, avoiding the cumbersome process of repeated etching and removal after the pattern is transferred to the substrate material. Therefore, it has advantages such as cost savings, simplified processes, and improved pattern accuracy. It is widely used in the surface planarization and support layers and pixel definition layers (PDLs) of flexible display thin-film transistors (TFTs), as well as redistribution layers and interlayer insulation in semiconductor manufacturing, and is one of the new materials urgently needed by the country.

[0003] Based on different photoreaction mechanisms, PSPI can be divided into negative and positive PSPI. The former undergoes cross-linking and curing after exposure, inhibiting dissolution, while the unexposed portions dissolve; it is often developed using organic solvents. The latter, however, promotes dissolution after exposure, and the unexposed portions remain on the substrate surface after development; it is generally developed using alkaline aqueous solutions. The earliest commercially available PSPI photoresists were primarily negative PSPI, which introduces methacrylate photosensitive groups onto the macromolecular chain through esterification or ionization reactions to form polyamide esters or polyamic acid salts, which then undergo cross-linking reactions after exposure. Compared to positive PSPI, negative PSPI has advantages such as strong adhesion to the substrate and high sensitivity, but it also has obvious disadvantages. For example, ester-type and salt-type negative PSPI require thermal imidization (>350℃) after development to obtain a stable patterned film. The volatilization of a large amount of solvent and by-products in this heat treatment process can easily lead to problems such as low film retention (~50%) and mismatch between the thermal expansion coefficients of the PSPI film and the substrate. At the same time, with the development of technologies such as 5G communication, electronic materials are required to have low dielectric constants and dielectric losses to improve the communication quality of devices. In addition, when PSPI photoresist is used, the adhesion between PSPI resin and glass or silicon wafer is also one of the important technical indicators. However, the interfacial compatibility between polymer materials and inorganic materials such as glass or silicon wafers has always been one of the problems that urgently need to be solved in this field. For example, invention patent (CN 202111518790.9) discloses a method for reducing the dielectric constant and dielectric loss of PSPI resin by introducing low-polarity alicyclic structural units, and invention patent (CN 202211061598.6) discloses a method for improving the adhesion between the resin and silicon wafers or glass surfaces by adding a silane coupling agent to a photosensitive polyimide composition. However, neither of these disclosed technologies provides a PSPI resin that can simultaneously improve dielectric properties and interfacial adhesion. Therefore, there is a need for effective structural design of polyimide resins to develop a PSPI resin that combines high resolution, low dielectric constant, low coefficient of thermal expansion, and high adhesion. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a photosensitive polyimide resin, a polyimide composition and a method for preparing the same, so as to overcome the defects of the prior art in which PSPI resin cannot simultaneously have high resolution, low dielectric constant, low coefficient of expansion and high adhesion.

[0005] This invention provides a photosensitive polyimide resin, the molecular structure of which is shown below:

[0006]

[0007] Among them, the X structure is derived from aminated hyperbranched polysiloxane or its derivatives, the Y structure is derived from a diamine monomer containing a photosensitive unit, and the Ar structure is derived from a dianhydride monomer; the molar ratio of repeating unit m:n is 0.5:9.5 to 3:7.

[0008] Preferably, the X structure is derived from one of the amino-modified hyperbranched polysiloxane NH2-HBPSi or the trifluoromethyl-containing amino-modified hyperbranched polysiloxane NH2-CF3-HBPSi.

[0009] Preferably, the degree of branching of the aminated hyperbranched polysiloxane is 0.5 to 0.9, and the surface amino content is 0.1 to 0.4 mmol / g.

[0010] Preferably, the Y structure is one of the following structures:

[0011]

[0012] In the formula, the R group is one of the following structures:

[0013]

[0014] Preferably, the diamine monomer in the Y structure is one of 3,5-diaminobenzoic acid (DABA), 4,4'-diaminobiphenyl-2,2-dicarboxylic acid (2,2'-DCB), or 4,4'-diamino-3,3'-dicarboxylic terphenyl (4,4'-DTDA).

[0015] Preferably, the Ar structure is one of the following structures:

[0016]

[0017] Preferably, the dianhydride monomer is one of cyclobutanetetracarboxylic dianhydride (CBDA), 1,2,4,5-cyclohexanetetracarboxylic dianhydride (HPMDA), bisphenol A type diether dianhydride (BPADA), pyromellitic dianhydride (PMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 4,4'-oxophthalic anhydride (ODPA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA), 3,3,4,4-diphenylsulfone tetracarboxylic dianhydride (DSDA), or hexafluorodianhydride (6FDA).

[0018] This invention provides a method for preparing photosensitive polyimide resin, comprising the following steps:

[0019] (1) Under nitrogen protection, the aminated hyperbranched polysiloxane and diamine monomer are dissolved in an aprotic polar solvent and stirred thoroughly to mix evenly; then, dianhydride monomers with a molar amount equal to the sum of the aminated hyperbranched polysiloxane and diamine monomers are added to the reaction system and stirred thoroughly at 0-5℃ for 20-28h to obtain a transparent viscous polyimide precursor solution;

[0020] (2) Under nitrogen protection, add a compound containing a photosensitive unit and a catalyst in the same molar amount as the diamine monomer to the reaction solution of step (1), and react at 60-80℃ for 4-8h to synthesize photosensitive polyimide resin.

[0021] Preferably, the solid content of the reactants in the reaction system in step (1) is 10wt%-20wt%.

[0022] Preferably, the aprotic polar solvent in step (1) is one of N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF) or dimethyl sulfoxide (DMSO).

[0023] Preferably, the compound containing the photosensitive unit in step (2) is one of glycidyl methacrylate, glycidyl acrylate, or cinnamyl alcohol.

[0024] Preferably, the catalyst in step (2) is triethylenediamine, and the amount added is 1wt%-3wt%.

[0025] The present invention provides a photosensitive polyimide resin composition comprising the above-mentioned photosensitive polyimide resin, an initiator, and an active diluent.

[0026] Preferably, the initiator is one of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (Irgacure 819), 2-hydroxy-2-methyl-1-phenyl-1-propanone (Irgacure 1173), and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO); the reactive diluent is one of 1-vinyl-2-pyrrolidone (NVP), butyl acrylate (BA), 1,6-hexanediol diacrylate (HDDA), and tripropylene glycol diacrylate (TPGDA).

[0027] More preferably, the initiator is one of Irgacure 819 and Irgacure 1173.

[0028] More preferably, the reactive diluent is one of NVP and TPGDA.

[0029] Preferably, the initiator content in the photosensitive polyimide resin composition is 1wt%-5wt%, and the reactive diluent content is 10wt%-20wt%.

[0030] More preferably, the initiator content is 3 wt% and the reactive diluent content is 10 wt%.

[0031] The present invention also provides a method for preparing a photosensitive polyimide resin composition, comprising the following steps: under nitrogen protection, adding an initiator and an active diluent to a photosensitive polyimide resin, and stirring thoroughly to obtain a photosensitive polyimide resin composition.

[0032] The present invention also provides a polyimide patterned film, which is prepared by the following steps: spin-coating a photosensitive polyimide resin composition onto the surface of a silicon wafer, soft baking at low temperature, exposure treatment under an exposure machine, development, and high-temperature baking treatment to obtain the film.

[0033] Preferably, the polyimide patterned film is prepared by the following steps: spin-coating a photosensitive polyimide resin composition onto the surface of a silicon wafer, baking it at 80°C for 10 minutes, and then exposing it in an exposure machine (350 mJ / cm). 2 Finally, after development and high-temperature baking (300℃, 10min), a patterned film is obtained.

[0034] Beneficial effects

[0035] (1) The present invention designs the structure of the polyimide resin backbone and introduces the aminated hyperbranched polysiloxane unit with hydrophobic properties into the polyimide molecular backbone. The micro-crosslinking structure between molecular chains formed by the above structure and the crosslinking reaction of the photosensitive unit can effectively improve the resolution of the photoresist and reduce the thermal expansion coefficient of the patterned film.

[0036] (2) The present invention is based on the low polarity and hydrophobicity of the abundant Si-O-Si units in hyperbranched polysiloxanes, which can reduce the dielectric constant of patterned thin films.

[0037] (3) In addition, the Si-O-Si network units in the polyimide backbone of the present invention have better interfacial compatibility with glass and silicon wafers, thereby forming stronger interfacial forces, improving the adhesion between photoresist and substrate, and thus developing high-adhesion photoresist materials. Attached Figure Description

[0038] Figure 1 The photolithographic pattern of the photosensitive polyimide photoresist prepared in Example 1. Detailed Implementation

[0039] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0040] Performance testing conditions for polyimide photoresist and its patterned thin film in the embodiments and comparative examples of this invention:

[0041] Photoresist exposure and development: The HS-6200 fully automatic exposure machine from Suzhou Hisilicon Microelectronics Technology Co., Ltd. was used, and the developer was N-methyl-pyrrolidone (NMP).

[0042] Thermal expansion coefficient test: The test was conducted using a thermomechanical analyzer (Q400) from TA Instruments, Inc., USA.

[0043] Dielectric performance testing: The tests were conducted using a Novocontrol concept 40 broadband dielectric impedance spectrometer from Novocontrol GmbH, Germany.

[0044] Adhesion test: Photosensitive polyimide photoresist was applied to a smooth silicon wafer, and a patterned film was formed on the wafer surface through processes such as exposure, development, drying, and post-baking. The peel strength was tested using a KJ-1065A peel strength tester from Kejian Instruments.

[0045] Example 1

[0046] Under nitrogen protection, aminated hyperbranched polysiloxane NH2-HBPSi and diamine monomer DABA were dispersed in a three-necked flask containing N,N-dimethylacetamide (DMAc) solvent, with a molar ratio of NH2-HBPSi:DABA of 3:7. After complete dissolution, dianhydride monomer BTDA was added to the reaction system in an equimolar amount equal to the sum of NH2-HBPSi and DABA, controlling the solid content of the reactants to 15 wt%. The reaction temperature was controlled at 5°C, and the mixture was stirred for 24 h to obtain a transparent, viscous polyamic acid precursor solution. Under nitrogen protection, glycidyl methacrylate in an equimolar amount equal to DABA and triethylenediamine (1 wt%) as a catalyst were added to the above reaction solution. The reaction temperature was controlled at 80°C, and the reaction was carried out for 5 h to obtain a photosensitive polyimide resin.

[0047] Add 3 wt% of initiator Irgacure 819 and 10 wt% of reactive diluent NVP to photosensitive polyimide resin, and stir thoroughly to obtain a photosensitive polyimide resin composition.

[0048] The above-mentioned polyimide photoresist was spin-coated onto a clean silicon wafer surface and baked at 80°C for 10 minutes, followed by exposure treatment (350 mJ / cm²) using an exposure machine. 2 Finally, after development and high-temperature baking (300℃, 10 min), a patterned film is obtained, such as... Figure 1 The photolithographic pattern of the photosensitive polyimide photoresist is shown.

[0049] Example 2

[0050] Under nitrogen protection, aminated hyperbranched polysiloxane NH2-HBPSi and diamine monomer DABA were dispersed in a three-necked flask containing N,N-dimethylacetamide (DMAc) solvent, with a molar ratio of NH2-HBPSi:DABA of 1:9. After complete dissolution, dianhydride monomer BTDA was added to the reaction system in an equimolar amount equal to the sum of NH2-HBPSi and DABA, controlling the solid content of the reactants to 15 wt%. The reaction temperature was controlled at 5°C, and the mixture was stirred for 24 h to obtain a transparent, viscous polyamic acid precursor solution. Under nitrogen protection, glycidyl methacrylate in an equimolar amount equal to DABA and triethylenediamine (1 wt%) as a catalyst were added to the above reaction solution. The reaction temperature was controlled at 80°C, and the reaction was carried out for 5 h to obtain a photosensitive polyimide resin.

[0051] Add 3 wt% of initiator Irgacure 819 and 10 wt% of reactive diluent NVP to photosensitive polyimide resin, and stir thoroughly to obtain a photosensitive polyimide resin composition.

[0052] The above-mentioned polyimide photoresist was spin-coated onto a clean silicon wafer surface and baked at 80°C for 10 minutes, followed by exposure treatment (350 mJ / cm²) using an exposure machine. 2 Finally, after development and high-temperature baking (300℃, 10min), a patterned film is obtained.

[0053] Example 3

[0054] Under nitrogen protection, aminated hyperbranched polysiloxane NH2-HBPSi and diamine monomer 2,2'-DCB were dispersed in a three-necked flask containing N,N-dimethylacetamide (DMAc) solvent, with a molar ratio of NH2-HBPSi:2,2'-DCB of 3:7. After complete dissolution, dianhydride monomer BPDA was added to the reaction system in an equimolar amount of the sum of NH2-HBPSi and 2,2'-DCB, controlling the solid content of the reactants to 15 wt%. The reaction temperature was controlled at 5°C, and the mixture was stirred for 24 h to obtain a transparent, viscous polyamic acid precursor solution. Under nitrogen protection, glycidyl methacrylate in an equimolar amount of 2,2'-DCB and triethylenediamine (1 wt%) as a catalyst were added to the above reaction solution. The reaction temperature was controlled at 80°C, and the reaction was carried out for 5 h to obtain photosensitive polyimide resin.

[0055] Add 3 wt% of initiator Irgacure 819 and 10 wt% of reactive diluent NVP to photosensitive polyimide resin, and stir thoroughly to obtain a photosensitive polyimide resin composition.

[0056] The above-mentioned polyimide photoresist was spin-coated onto a clean silicon wafer surface and baked at 80°C for 10 minutes, followed by exposure treatment (350 mJ / cm²) using an exposure machine. 2 Finally, after development and high-temperature baking (300℃, 10min), a patterned film is obtained.

[0057] Example 4

[0058] Under nitrogen protection, trifluoromethyl-containing aminated hyperbranched polysiloxane NH2-CF3-HBPSi and diamine monomer DABA were dispersed in a three-necked flask containing N,N-dimethylacetamide (DMAc) solvent, with a molar ratio of NH2-CF3-HBPSi:DABA of 3:7. After complete dissolution, dianhydride monomer BTDA was added to the reaction system in an equimolar amount of the sum of NH2-CF3-HBPSi and DABA, controlling the solid content of the reactants to 15 wt%. The reaction temperature was controlled at 5°C, and the mixture was stirred for 24 h to obtain a transparent, viscous polyamic acid precursor solution. Under nitrogen protection, glycidyl methacrylate in an equimolar amount of DABA and triethylenediamine (1 wt%) as a catalyst were added to the above reaction solution, and the reaction temperature was controlled at 80°C. The reaction was carried out for 5 h to obtain a photosensitive polyimide resin.

[0059] Add 3 wt% of initiator Irgacure 819 and 10 wt% of reactive diluent NVP to photosensitive polyimide resin, and stir thoroughly to obtain a photosensitive polyimide resin composition.

[0060] The above-mentioned polyimide photoresist was spin-coated onto a clean silicon wafer surface and baked at 80°C for 10 minutes, followed by exposure treatment (350 mJ / cm²) using an exposure machine. 2 Finally, after development and high-temperature baking (300℃, 10min), a patterned film is obtained.

[0061] Example 5

[0062] Under nitrogen protection, trifluoromethyl-containing aminated hyperbranched polysiloxane NH2-CF3-HBPSi and diamine monomer DABA were dispersed in a three-necked flask containing N,N-dimethylacetamide (DMAc) solvent, with a molar ratio of NH2-CF3-HBPSi:DABA of 3:7. After complete dissolution, dianhydride monomer BTDA was added to the reaction system in an equimolar amount of the sum of NH2-CF3-HBPSi and DABA, controlling the solid content of the reactants to 15 wt%. The reaction temperature was controlled at 5°C, and the mixture was stirred for 24 h to obtain a transparent, viscous polyamic acid precursor solution. Under nitrogen protection, glycidyl methacrylate in an equimolar amount of DABA and triethylenediamine (1 wt%) as a catalyst were added to the above reaction solution, and the reaction temperature was controlled at 80°C. The reaction was carried out for 5 h to obtain a photosensitive polyimide resin.

[0063] Add 3 wt% of initiator Irgacure 1173 and 10 wt% of reactive diluent TPGDA to photosensitive polyimide resin, and stir thoroughly to obtain a photosensitive polyimide resin composition.

[0064] The above-mentioned polyimide photoresist was spin-coated onto a clean silicon wafer surface and baked at 80°C for 10 minutes, followed by exposure treatment (350 mJ / cm²) using an exposure machine. 2 Finally, after development and high-temperature baking (300℃, 10min), a patterned film is obtained.

[0065] Comparative Example 1

[0066] Under nitrogen protection, the diamine monomer DABA was dispersed in a three-necked flask containing N,N-dimethylacetamide (DMAc) solvent. After complete dissolution, an equimolar amount of the dianhydride monomer BTDA was added to the reaction system, controlling the solid content of the reactants to 15 wt%. The reaction temperature was controlled at 5°C, and the mixture was stirred for 24 h to obtain a viscous polyamic acid precursor solution. Under nitrogen protection, an equimolar amount of glycidyl methacrylate and a catalyst triethylenediamine (1 wt%) were added to the above reaction solution. The reaction temperature was controlled at 80°C, and the reaction was carried out for 5 h to obtain a photosensitive polyimide resin.

[0067] Add 3 wt% of initiator Irgacure 819 and 10 wt% of reactive diluent NVP to photosensitive polyimide resin, and stir thoroughly to obtain a photosensitive polyimide resin composition.

[0068] The above-mentioned polyimide photoresist was spin-coated onto a clean silicon wafer surface and baked at 80°C for 10 minutes, followed by exposure treatment (350 mJ / cm²) using an exposure machine. 2 Finally, after development and high-temperature baking (300℃, 10min), a patterned film is obtained.

[0069] Comparative Example 2

[0070] Under nitrogen protection, hyperbranched polysiloxane HBPSi (without amino units) and diamine monomer DABA were dispersed in a three-necked flask containing N,N-dimethylacetamide (DMAc) solvent, with a molar ratio of HBPSi:DABA of 3:7. After complete dissolution, dianhydride monomer BTDA was added to the reaction system in an equimolar amount equal to the sum of HBPSi and DABA, controlling the solid content of the reactants to 15 wt%. The reaction temperature was controlled at 5°C, and the mixture was stirred for 24 h to obtain a viscous polyamic acid precursor solution. Under nitrogen protection, glycidyl methacrylate in an equimolar amount equal to DABA and triethylenediamine (1 wt%) as a catalyst were added to the above reaction solution. The reaction temperature was controlled at 80°C, and the reaction was carried out for 5 h to obtain a photosensitive polyimide resin.

[0071] Add 3 wt% of initiator Irgacure 819 and 10 wt% of reactive diluent NVP to photosensitive polyimide resin, and stir thoroughly to obtain a photosensitive polyimide resin composition.

[0072] The above-mentioned polyimide photoresist was spin-coated onto a clean silicon wafer surface and baked at 80°C for 10 minutes, followed by exposure treatment (350 mJ / cm²) using an exposure machine. 2 Finally, after development and high-temperature baking (300℃, 10min), a patterned film is obtained.

[0073] Table 1 shows a performance comparison of the photosensitive polyimide photoresists obtained in the embodiments and comparative examples of the present invention.

[0074] Table 1

[0075]

[0076] As can be seen from Table 1, the photosensitive polyimide photoresist prepared in this invention has excellent properties such as high resolution, low dielectric constant, low coefficient of thermal expansion and high adhesion compared with polyimide photoresist without amino-modified hyperbranched polysiloxane.

Claims

1. A photosensitive polyimide resin, characterized by comprising: The molecular structure is shown as follows: ； The X structure is derived from an aminated hyperbranched polysiloxane NH2-HBPSi or an aminated hyperbranched polysiloxane NH2-CF3-HBPSi containing a trifluoromethyl group, with a branching degree of 0.5-0.9 and a surface amino content of 0.1-0.4 mmol / g; The Y structure is derived from a diamine monomer containing a photosensitive unit, and is one of the following structures: ， In the formula, the R group is one of the following structures: ； The Ar structure is derived from a dianhydride monomer; The m:n molar ratio of the repeating unit is 0.5:9.5-3:

7.

2. The photosensitive polyimide resin according to claim 1, characterized by The Ar structure is one of the following structures: 。 3. A preparation method of the photosensitive polyimide resin according to any one of claims 1-2, comprising the following steps: (1) under nitrogen protection, the aminated hyperbranched polysiloxane and the diamine monomer are dissolved in an aprotic polar solvent, fully stirred and uniformly mixed; then, a dianhydride monomer in an amount equal to the sum of the aminated hyperbranched polysiloxane and the diamine monomer is added to the reaction system, and fully stirred at 0-5 °C for 20-28 h to obtain a transparent viscous polyimide precursor solution; (2) under nitrogen protection, an equal molar amount of a compound containing a photosensitive unit and a catalyst are added to the polyimide precursor solution of step (1), and reacted at 60-80 °C for 4-8 h to obtain the photosensitive polyimide resin.

4. A photosensitive polyimide resin composition, comprising the photosensitive polyimide resin according to claim 1, and an initiator and an active diluent.

5. The photosensitive polyimide resin composition according to claim 4, wherein The initiator is one of phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide; and the active diluent is one of 1-vinyl-2-pyrrolidone, butyl acrylate, 1,6-hexanediol diacrylate, and tripropyleneglycol diacrylate.

6. The photosensitive polyimide resin composition according to claim 4, wherein The content of the initiator is 1wt%-5wt%, and the content of the active diluent is 10wt%-20wt%.

7. A method for producing the photosensitive polyimide resin composition according to any one of claims 4 to 6, characterized by, The method comprises the following steps: under nitrogen protection, the initiator and the active diluent are added to the photosensitive polyimide resin, and fully stirred to obtain the photosensitive polyimide resin composition.

8. A polyimide patterned film, prepared by the following steps: spin coating the photosensitive polyimide resin composition according to claim 4 on the surface of a silicon wafer, low-temperature soft baking, exposing under an exposure machine, developing, and high-temperature baking to obtain a film.

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