Bisphenol fluorene type resin, preparation method thereof, negative photoresist and application
Bisphenol fluorene resin was prepared through interfacial polycondensation, and the monomer selection and molar ratio were optimized, which solved the problem of insufficient performance of existing photoresist, achieved high thermal stability, chemical stability and development of photoresist, and reduced the occurrence of pattern defects.
Patent Information
- Application Number
- CN202411938447.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-03-14
AI Technical Summary
Existing photoresist cannot meet the requirements of higher etch resistance, thermal stability and development.
Bisphenol fluorene resin was prepared by interfacial polycondensation, and the polymerization of different monomers A, B and C was used to optimize the selection and molar ratio of the monomers to prepare UV negative photoresist with excellent performance.
The thermal stability, chemical stability and development properties of photoresist are greatly improved, the occurrence of pattern defects is reduced, and the stability and resolution of photolithographic patterns are improved.
Smart Images
Figure CN119613687A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of photoresists, and in particular to a bisphenol fluorene resin and a preparation method thereof, a negative photoresist and applications thereof. Background Art
[0002] Fluorene derivatives have a rigid plane structure and good thermal and photochemical stability, so they can be used as raw materials for products such as epoxy resins with high heat resistance and good optical properties and new heat-resistant polycarbonates. Bisphenol fluorene is a bisphenol compound with a Cardo ring structure. Its molecular formula is C25H18O2. As a multifunctional chemical substance, it is an important raw material for the preparation of new polymer materials. Using bisphenol fluorene as a monomer or modifier, we can produce excellent products. The excellent properties of fluorene-based polymer materials synthesized using bisphenol fluorene and its derivatives as raw materials are mainly manifested in: extremely high thermal stability, extremely low glass transition temperature, and it also has excellent dielectric properties, good mechanical properties and resistance to chemical substances. In addition, bisphenol fluorene as a synthetic monomer can also be used to prepare a variety of functional polymer materials, such as photosensitive materials, photoconductors, heat transfer materials, and electrical conductor insulators.
[0003] Photoresist, also known as photoresist, is a light-sensitive mixed liquid. Photoresist is the core material of the photolithography process. In the photolithography process, photoresist is applied to the substrate. After light or radiation is irradiated to the substrate through the mask, the solubility of the photoresist in the developer solution changes. After the soluble part is dissolved by the solution, the photoresist layer forms a pattern corresponding to the mask, and then the pattern transfer is completed on the substrate by etching. And depending on the downstream application, the substrate can be a printed circuit board, a round wafer, a panel and an integrated circuit board.
[0004] According to the reaction mechanism of photoresist, it can be divided into two categories: one is negative photoresist, which is insoluble after exposure and the unexposed area is dissolved during development to form a pattern. The other is positive photoresist, which is soluble after exposure and the exposed area is dissolved during development to form a pattern.
[0005] Photoresist needs to have etching resistance, thermal stability, and good developability at the same time, but existing photoresists cannot meet higher requirements. Therefore, obtaining a photoresist with comprehensive excellent performance is an urgent problem to be solved. Summary of the invention
[0006] In order to improve the etching resistance, thermal stability, developability and other properties of photoresist, the present application provides a bisphenol fluorene type resin and a preparation method thereof, a negative photoresist and application.
[0007] First aspect: The present application provides a bisphenol fluorene type resin, which is mainly prepared by interfacial polycondensation of A monomer, B monomer and C monomer, wherein the A monomer contains alkali-soluble groups selected from phenolic hydroxyl, carboxyl, acid anhydride and amide; the B monomer and the C monomer are both selected from one of terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride or trimesoyl chloride.
[0008] Preferably, the A monomer has the following structural formula: Among them, R1 and R2 are one of hydroxyl and carboxyl; R3 and R4 are one of hydrogen, methyl, ethyl, propyl and butyl.
[0009] The B monomer is isophthaloyl chloride; the C monomer is terephthaloyl chloride.
[0010] Preferably, the molar ratio of the A monomer: the B monomer: the C monomer is: 10:4-7:4-7.
[0011] Bisphenol fluorene resin has the advantages of good thermal stability, strong etching resistance and easy development. Bisphenol fluorene (BHPF) is a bisphenol compound with a Cardo ring structure. The introduction of large side groups in the system can increase the molar volume of the system and achieve the effect of reducing the dielectric constant; at the same time, the introduction of large side groups will destroy the regularity of the molecules, and the molecular chain has a greater degree of freedom, which makes the polymer have excellent processing properties; in addition, the large side groups have strong rigidity, which increases the thermal properties of the polymer. The A monomer contains alkali-soluble groups and has excellent solubility and film-forming properties. Optimize and adjust the type of A monomer, adjust the molecular structure composition and the type of substitution groups, so that the molecular state of the polymer formed by polymerization is more stable and adaptable, not easily affected by the external environment, and improve the sensitivity, resolution and other properties of the photoresist.
[0012] The B monomer and the C monomer are co-polymerized to prepare a bisphenol fluorene type polymer, which shields the electronic effect of the active group, so that the active group of the photoresist is better protected in the molecular space, and the wetting performance of the photoresist is also improved. The inventor found that when the B monomer and the C monomer are selected from different phthaloyl chlorides, namely isophthaloyl chloride and terephthaloyl chloride, and the molar ratio of the A monomer: the B monomer: the C monomer is 10:4-7:4-7, the developing property is better. This may be due to the fact that the above monomer selection further improves the arrangement state of the copolymer molecular structure, and the obtained polymer has good alkali solubility, thermal stability, chemical stability, and excellent self-fluidity and surface tension state, reducing the morphological defects of the photolithographic pattern, and the resin prepared within the above monomer ratio range achieves a balance of alkali solubility, thermal stability, chemical stability, and self-fluidity, thereby obtaining a better developing effect.
[0013] On the other hand, the present application provides a method for preparing a bisphenol fluorene resin, comprising the following steps: S1: Add monomer A and catalyst into water and stir to obtain an aqueous phase; dissolve monomer B and monomer C in an organic solvent to obtain an organic phase; slowly drop the organic phase into the aqueous phase in an ice-water bath at a constant temperature of -5°C to 0°C, react for 0.5-1.5h, and then take it out; continue to react at room temperature for 3-5h, then perform end-capping, react for another 1-3h, and terminate the reaction to obtain a polymer solution; S2: The polymer solution is adjusted to neutral, precipitated with a solvent to obtain a translucent gel, which is then redissolved, precipitated, washed, and vacuum dried.
[0014] Preferably, the organic solvent in S1 is one or more of dichloromethane, chloroform, acetonitrile, cyclohexanone and cyclohexane; and the solvent in S2 is one or more of methanol and ethanol.
[0015] Preferably, the catalyst is one or more of benzyltriethylammonium chloride, tetrabutylammonium bromide and tetrabutylammonium chloride.
[0016] The inventors prepared bisphenol fluorene resin by interfacial polycondensation, and the preparation process is simple, the reaction conditions are mild, the yield of the obtained product is high, the side reaction is less, and the purity is further improved by multiple precipitations.
[0017] On the other hand, the present application also provides a UV negative photoresist, comprising the following raw materials in parts by weight: 60-100 parts of bisphenol fluorene resin, 10-30 parts of active diluent, 2-10 parts of photoinitiator, and 20-40 parts of solvent.
[0018] Preferably, the photoinitiator is one or more of 1-hydroxycyclohexyl benzophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholine-1-propanone, and 2,4,6-(trimethylbenzoyl)di-p-tolylphosphine oxide.
[0019] Preferably, the active diluent is one or more of ethoxylated trimethylolpropane triacrylate EOTMPTA and tripropylene glycol diacrylate TPGDA.
[0020] Preferably, the solvent is one or more of propylene glycol methyl ether, ethyl lactate, ethyl acetate, ethylene glycol monomethyl ether acetate, cyclohexanone, 3-ethoxypropionic acid, and 2-heptanone.
[0021] The bisphenol fluorene type resin prepared in the present application is used in photoresist and has the advantages of good film-forming property, good thermal stability, strong etching resistance and good development.
[0022] The present application also provides an application of UV negative photoresist, comprising the following steps: coating the UV negative photoresist on a copper substrate, pre-baking at 80-90°C for 30-50 minutes; covering a film on the coated surface of the copper substrate, exposing it at 80-152mj / cm; and then developing it in an alkaline solution.
[0023] Preferably, the alkali solution is selected from one of KOH or Na2CO3 solution.
[0024] In summary, this application has the following beneficial technical effects: 1. This application adopts A, B, C different monomers to polymerize to prepare bisphenol fluorene type resin, which is applied to UV negative photoresist. It can migrate to the resin surface, improve the self-fluidity and surface tension of the photoresist system, greatly reduce the generation of graphic defects such as T-top morphology, and make the photolithography graphics more stable; at the same time, it has excellent thermal stability and chemical stability.
[0025] 2. This application further improves the comprehensive performance of the copolymer by optimizing the selection and molar ratio of monomer A, monomer B and monomer C to obtain better lithography patterns.
[0026] 3. The polyarylate (PAR) structure in the resin structure of the present application also has excellent properties such as low moisture absorption, high flame retardancy and low dielectric constant, thereby improving the comprehensive performance of the photoresist. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 This is a SEM image of the photoresist application in Example 1 of the present application. DETAILED DESCRIPTION
[0028] The present application is further described in detail below through examples.
[0029] All raw materials in the examples are commercially available. Example
[0030] Example 1 The bisphenol fluorene type resin is prepared by polymerizing monomer A, monomer B, and monomer C, wherein monomer A is 9,9-bis(4-hydroxyphenyl)fluorene, monomer B is isophthaloyl chloride, and monomer C is terephthaloyl chloride. The preparation method of the bisphenol fluorene type resin of this embodiment comprises the following steps: S1: Weigh 1.011 g NaOH, 3.576 g BHPF, 0.0462 g BTEAC (benzyltriethylammonium chloride), and 0.0520 g NaHSO 3Add 20 ml of deionized water into a three-necked flask to prepare the aqueous phase, and stir magnetically at room temperature for 30 min; weigh 0.844 g of IPC (isophthaloyl chloride) and 1.267 g of TPC (terephthaloyl chloride) and dissolve them in 40 ml of CH 2 Cl 2 The organic phase was prepared in a small beaker and magnetically stirred at room temperature for 30 minutes; the flask of the aqueous phase was placed in a constant temperature ice water bath (-5℃-0℃), the magnetic stirring was turned on, and the organic phase was slowly added dropwise to the aqueous phase, and the reaction was carried out after 1 hour; the stirring was continued at room temperature for another 4 hours, and 0.0125g PTBP (p-tert-butylphenol) was added for end-capping; the stirring was continued for 2 hours to terminate the reaction to obtain a polymer solution; S2: Add acetic acid dropwise to adjust the obtained polymer solution to neutrality, precipitate with methanol, and filter to obtain a translucent gel. The product is redissolved in chloroform, precipitated with methanol, filtered, repeatedly washed with deionized water, and vacuum dried at 70°C for 2h to obtain a white copolymer powder, namely, bisphenol fluorene resin.
[0031] UV negative photoresist: 68g of bisphenol fluorene resin, 6g of photoinitiator 1-hydroxycyclohexyl benzophenone, 15g of active diluent (EOTMPTA and TPGDA mass ratio 1:1), 20g of solvent ethyl acetate, mixed and magnetically stirred until mixed evenly to obtain UV negative photoresist. Apply UV negative photoresist on a copper plate and pre-bake at 80°C for 40 minutes; cover the baked sample with film; expose at 152mj / cm, and place the exposed sample in 1% Na 2 CO 3 The photoresist pattern was obtained by immersing the samples in the solution for 30 seconds.
[0032] Example 2 The bisphenol fluorene type resin is prepared by polymerizing monomer A, monomer B, and monomer C, wherein monomer A is 9,9-bis(4-hydroxyphenyl)fluorene, monomer B is isophthaloyl chloride, and monomer C is terephthaloyl chloride. The preparation method of the bisphenol fluorene type resin of this embodiment comprises the following steps: S1: Weigh 1.011 g NaOH, 3.576 g BHPF, 0.0462 g BTEAC (benzyltriethylammonium chloride), and 0.0520 g NaHSO 3 Add 20 ml of deionized water into a three-necked flask to prepare the aqueous phase, and stir magnetically at room temperature for 30 min; weigh 1.38 g of IPC (isophthaloyl chloride) and 0.92 g of TPC (terephthaloyl chloride) and dissolve them in 40 ml of CH 2 Cl 2The organic phase was prepared in a small beaker and magnetically stirred at room temperature for 30 minutes; the flask of the aqueous phase was placed in a constant temperature ice water bath (-5℃-0℃), the magnetic stirring was turned on, and the organic phase was slowly added dropwise to the aqueous phase, and the reaction was carried out after 1 hour; the stirring was continued at room temperature for another 4 hours, and 0.0125g PTBP (p-tert-butylphenol) was added for end-capping; the stirring was continued for 2 hours to terminate the reaction to obtain a polymer solution; S2: Add acetic acid dropwise to adjust the obtained polymer solution to neutrality, precipitate with methanol, and filter to obtain a translucent gel. The product is redissolved in chloroform, precipitated with methanol, filtered, repeatedly washed with deionized water, and vacuum dried at 70°C for 2h to obtain a white copolymer powder, namely, bisphenol fluorene resin.
[0033] UV negative photoresist: 68g of bisphenol fluorene resin, 6g of photoinitiator 1-hydroxycyclohexyl benzophenone, 15g of active diluent (EOTMPTA and TPGDA mass ratio 1:1), 20g of solvent ethyl acetate, mixed and magnetically stirred until mixed evenly to obtain UV negative photoresist. Apply UV negative photoresist on a copper plate and pre-bake at 90°C for 30 minutes; cover the baked sample with film; expose at 127mj / cm, and place the exposed sample in 1% Na 2 CO 3 The photoresist pattern was obtained in the solution for 23 seconds.
[0034] Example 3 The only difference between Example 3 and Example 1 is that the molar ratio of A monomer: B monomer: C monomer is 1:1:1; the other resin preparation steps, gel making steps, and application steps are consistent with Example 1.
[0035] Example 4 The only difference between Example 4 and Example 1 is that the molar ratio of A monomer: B monomer: C monomer is 10:2:2; the other resin preparation steps, gel making steps, and application steps are consistent with Example 1.
[0036] Example 5 The only difference between Example 5 and Example 1 is that the B monomer is replaced by an equimolar amount of C monomer, that is, only C monomer is weighed when preparing the organic phase; the other resin preparation steps, gel making steps, and application steps are consistent with Example 1.
[0037] Example 6 The only difference between Example 6 and Example 1 is that the C monomer is replaced by an equimolar amount of B monomer, that is, only B monomer is weighed when preparing the organic phase; the other resin preparation steps, gel making steps, and application steps are consistent with Example 1.
[0038] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that BHPF is replaced by bisphenol A in an equal molar amount; the other resin preparation steps, glue making steps, and application steps are consistent with Example 1.
[0039] Performance testing: The performance of the embodiment and comparative example 1 was tested, and the test results are shown in Table 1: Adhesion test: The photoresist is coated on the copper plate and the adhesion test is performed by the hundred-grid method; High temperature and high humidity resistance: The photoresist is coated on a copper plate and placed in an environment of 150°C and 80% relative humidity for 30 hours, and then the adhesion is tested by the 100-grid method; Pattern resolution: ECLIPSE LV150A Nikon metallographic microscope is used to observe and test the minimum line width of the photoresist pattern. If the line width is below 100μm, the pattern is clean, and there is no peeling or gap, it is marked as "qualified". If the pattern is over-developed, the pattern falls off and the retained pattern has gaps or the development is not clean, the pattern cannot be made, and it is marked as "unqualified".
[0040] Table 1: It can be seen from Example 1, Example 2 and Comparative Example 1 that the photoresist prepared by bisphenol fluorene type resin in the present application has good adhesion, high temperature and high humidity resistance, and the pattern has no shedding, gaps, and develops cleanly; while Comparative Example 1 does not have bisphenol fluorene and its high temperature and high humidity resistance is poor, and the resolution is also poor when applied to photoresist, the pattern has many shedding and gaps, and the development is not clean.
[0041] It can be seen from Example 1 and Example 3-4 that when adjusting the ratio of A monomer, B monomer, and C monomer, the high temperature and high humidity resistance of B monomer and C monomer is reduced when there are too many or too few monomers, and the pattern does not fall off, but there are gaps and the development is not clean. This may be due to the fact that the large side groups in the resin polymer chain prepared by too little A monomer are reduced, and the thermal stability is deteriorated. The self-flowability of the resin is poor when there are too few monomers B and C, which also affects the coating of the photoresist, resulting in uneven distribution of adhesive points, poor thermal stability, and poor development effect. The resin prepared in the molar ratio of A monomer: B monomer: C monomer is within the range of 10:4-7:4-7 can have both excellent thermal stability and flowability, so that the obtained photoresist has high temperature and high humidity resistance, and the obtained pattern resolution is better.
[0042] It can be seen from Example 1 and Examples 5-6 that when the B monomer and the C monomer are the same, the photoresist has slightly poor high temperature and high humidity resistance and resolution, the pattern has no peeling, gaps, and unclean development. This may be because the different choices of B and C improve the arrangement state and molecular chain structure of the copolymer molecular structure, resulting in good processability and fluidity.
[0043] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.
Claims
1. A bisphenol fluorene type resin, characterized in that: The resin is mainly prepared by interfacial polycondensation of monomer A, monomer B and monomer C, wherein the monomer A contains alkali-soluble groups selected from phenolic hydroxyl, carboxyl, acid anhydride and amide; the monomer B and monomer C are selected from terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride or trimesoyl chloride.
2. The bisphenol fluorene type resin according to claim 1, characterized in that: The structural formula of the A monomer is as follows: Among them, R1 and R2 are one of hydroxyl and carboxyl; R3 and R4 are one of hydrogen, methyl, ethyl, propyl and butyl; the B monomer is isophthaloyl chloride; and the C monomer is terephthaloyl chloride.
3. The bisphenol fluorene type resin according to claim 2, characterized in that: The molar ratio of the A monomer: the B monomer: the C monomer is 10:4-7:4-7.
4. A method for preparing the bisphenol fluorene type resin according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: Add monomer A and catalyst into water and stir to obtain an aqueous phase; dissolve monomer B and monomer C in an organic solvent to obtain an organic phase; slowly drop the organic phase into the aqueous phase in an ice-water bath at a constant temperature of -5°C to 0°C, react for 0.5-1.5h, and then take it out; continue to react at room temperature for 3-5h, then perform end-capping, react for another 1-3h, and terminate the reaction to obtain a polymer solution; S2: The polymer solution is adjusted to neutral, precipitated with a solvent to obtain a translucent gel, which is then redissolved, precipitated, washed, and vacuum dried.
5. The method for preparing the bisphenol fluorene type resin according to claim 4, characterized in that: The organic solvent in S1 is one or more of dichloromethane, chloroform, acetonitrile, cyclohexanone, and cyclohexane; the solvent in S2 is one or more of methanol and ethanol.
6. The method for preparing the bisphenol fluorene type resin according to claim 4, characterized in that: The catalyst is one or more of benzyltriethylammonium chloride, tetrabutylammonium bromide and tetrabutylammonium chloride.
7. A UV negative photoresist, characterized in that: The invention comprises the following raw materials in parts by weight: 60-100 parts of the bisphenol fluorene resin according to any one of claims 1 to 3, 10-30 parts of an active diluent, 2-10 parts of a photoinitiator, and 20-40 parts of a solvent.
8. The UV negative photoresist according to claim 7, characterized in that: The photoinitiator is one or more of 1-hydroxycyclohexyl benzophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholine-1-propanone, and 2,4,6-(trimethylbenzoyl)di-p-tolylphosphine oxide.
9. The UV negative photoresist according to claim 7, characterized in that: The active diluent is one or more of ethoxylated trimethylolpropane triacrylate EOTMPTA and tripropylene glycol diacrylate TPGDA; the solvent is one or more of propylene glycol methyl ether, ethyl lactate, ethyl acetate, ethylene glycol monomethyl ether acetate, cyclohexanone, 3-ethoxypropionic acid, and 2-heptanone.
10. An application of the UV negative photoresist according to any one of claims 7 to 9, characterized in that: The method comprises the following steps: coating a UV negative photoresist on a copper substrate, pre-baking at 80-90°C for 30-50 minutes; covering a film on the coated surface of the copper substrate, exposing it at 80-152 mj / cm; and developing it in an alkaline solution.