A method for preparing and using a benzoxazine film-forming resin precursor material

Abstract

This invention provides a method for preparing benzoxazine film-forming resin precursor materials and their applications, belonging to the fields of organic synthesis and semiconductor photoresist technology. The method uses substituted o-aminophenol as a starting material and proceeds through four steps: nucleophilic substitution cyclization, regioselective bromination, amide-selective reduction, and reductive amination, to prepare N-substituted brominated dihydrobenzoxazine compounds. This invention achieves specificity of the sequential reaction sites through differences in reactivity and control of process parameters, resulting in products with high purity and ultra-low or even no metal ion residue. The N-substituted brominated dihydrobenzoxazine compounds prepared by this invention have low curing temperatures, high crosslinking activity, and possess both bromine atom active sites and a rigid benzoxazine framework, making them suitable as precursor materials for film-forming resins in photoresists.

Description

Technical Field

[0001] This invention relates to the field of photoresist material preparation, specifically to a method for preparing and applying a benzoxazine film-forming resin precursor material. Background Technology

[0002] As semiconductor chip manufacturing processes accelerate towards 7nm, 5nm, and below nodes, the pattern size of photolithography is approaching its physical limit, leading to multi-dimensional and extreme performance requirements for photoresist materials. In addition to the traditional requirements of high resolution and low linewidth roughness, advanced photoresists must also simultaneously meet the following requirements: post-baking stability above 150°C (to avoid pattern collapse and deformation), dielectric constant below 3.0 (to reduce signal delay), excellent resistance to dry etching (to ensure accurate pattern transfer), and ppb-level metal ion residue (to prevent device leakage failure).

[0003] As the core component of photoresist compositions, the molecular structure of the film-forming resin directly determines the final performance of the photoresist. Currently, phenolic resins and poly(p-hydroxystyrene) resins, widely used in industry, while possessing good solubility and developability, have inherent structural defects: phenolic resins have a low aromatic ring density and poor etching resistance; poly(p-hydroxystyrene) resins have a glass transition temperature of only around 130°C, and at high temperatures, the pattern shrinkage rate exceeds 10%, failing to meet the requirements of advanced processes.

[0004] Benzoxazine resins, as a new generation of thermosetting resins, exhibit great application potential due to their unique molecular structure. The six-membered oxazine ring in the benzoxazine resin molecule can form a three-dimensional cross-linked network after curing, exhibiting advantages such as zero shrinkage, low water absorption, and high heat resistance. Simultaneously, the benzene ring backbone endows it with excellent dry etching resistance, with an etching rate more than 30% lower than phenolic resins. However, traditional 1,3-benzoxazine resins suffer from excessively high curing temperatures and low cross-linking activity, limiting their application in photoresists. In particular, the low cross-linking activity leads to a slow curing rate under photo-triggered conditions, resulting in insufficient photoresist sensitivity.

[0005] To address the aforementioned issues, it is necessary to modify the benzoxazine resin to lower its curing temperature while increasing its crosslinking activity, thereby meeting the performance requirements of existing photoresist materials. Summary of the Invention

[0006] Furthermore, introducing bromine atom active sites into the benzoxazine molecule can regulate the curing behavior of the resin; it can also further improve the resin's etching resistance and thermal stability.

[0007] However, the bromination reaction has poor selectivity. Since the impurities and bromination products have similar physical properties, they cannot be separated by conventional purification methods, resulting in low product purity, which in turn seriously affects the resolution and linewidth roughness of the photoresist.

[0008] This invention innovatively discovers that significant differences in reactivity exist between different functional groups. By controlling the reaction temperature, feed ratio, and solvent system, each reaction step can be made to occur only at the target site, significantly suppressing side reactions. Based on this core discovery, this invention designs a new synthetic route using substituted o-aminophenol as the starting material. Through a four-step reaction involving nucleophilic substitution cyclization, regioselective bromination, amide-selective reduction, and reductive amination, bromobenzoxazine film-forming resin precursor materials can be prepared in high yield and with high selectivity.

[0009] In view of this, the present invention provides a method for preparing a benzoxazine film-forming resin precursor material and its application, so as to meet the performance requirements of existing photoresist materials.

[0010] To achieve the above objectives, the present invention provides a method for preparing a benzoxazine film-forming resin precursor material, comprising the following steps:

[0011] S1. Starting with compound 1, under alkaline conditions in the presence of alkali metal carbonates, compound 2 undergoes nucleophilic substitution and cyclization reactions with haloacetyl halides. After the reaction is completed, compound 2 is obtained by quenching, extraction, and purification.

[0012] The compound 1 is o-aminophenol or o-aminophenol with a group 1 on the benzene ring, wherein the group 1 is one of C1-C6 alkyl, C1-C6 alkoxy, fluorine substituent, chlorine substituent and bromine substituent;

[0013] Compound 2 is a benzoxazine-3(4H)-one compound;

[0014] S2. Compound 2 obtained in step S1 is reacted with N-bromosuccinimide in a polar aprotic solvent to undergo a regioselective electrophilic bromination reaction of the aromatic ring; after the reaction is completed, the compound is quenched, extracted and purified to obtain compound 3.

[0015] Compound 3 is a bromobenzoxazine-3(4H)-one compound with one or two bromine substituents on the benzene ring;

[0016] S3. Compound 3 obtained in step S2 is reacted with a borane-based reducing agent under an inert gas atmosphere to selectively reduce the amide carbonyl group to a methylene group. After the reaction is completed, the compound 4 is obtained by quenching, extraction, and purification.

[0017] Compound 4 is a bromodihydrobenzoxazine compound;

[0018] S4. Compound 4 obtained in step S3 is reacted with an aldehyde compound in the presence of a borohydride reducing agent to undergo a reduction amination reaction. After the reaction is completed, the compound is quenched, extracted, and purified to obtain compound 5, which is the benzoxazine film-forming resin precursor material.

[0019] Compound 5 is an N-substituted brominated dihydrobenzoxazine compound.

[0020] In one implementation, step S1 satisfies at least one of the following conditions:

[0021] (1) The alkali metal carbonate is one of potassium carbonate, sodium carbonate, and cesium carbonate;

[0022] (2) The haloacetyl halide is one of chloroacetyl chloride, bromoacetyl chloride, and iodoacetyl chloride;

[0023] (3) The reaction solvent is one of acetonitrile, tetrahydrofuran, and dichloromethane;

[0024] (4) The reaction temperature is 40-80℃ and the reaction time is 1-4 hours;

[0025] (5) The molar ratio of compound 1, haloacetyl halide, and alkali metal carbonate is 1:(1.1-1.5):(2.5-3.5).

[0026] In one implementation, step S2 satisfies at least one of the following conditions:

[0027] (1) The polar aprotic solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone;

[0028] (2) The reaction temperature is -5 to 10℃, and the reaction time is 8 to 15 hours;

[0029] (3) The molar ratio of compound 2 to N-bromosuccinimide is 1:(0.8-1.2).

[0030] In one implementation, step S3 satisfies at least one of the following conditions:

[0031] (1) The borane reducing agent is one of borane dimethyl sulfide complex and borane tetrahydrofuran complex;

[0032] (2) The reaction solvent is one of tetrahydrofuran or 1,4-dioxane;

[0033] (3) The reaction temperature is 50-70℃ and the reaction time is 1-3 hours;

[0034] (4) The molar ratio of compound 3 to borane reducing agent is 1:(2.0-3.0).

[0035] In one implementation, in step S4, at least one of the following conditions is met.

[0036] (1) The aldehyde compound is one of C1-C12 alkyl aldehydes, C3-C8 cycloalkyl aldehydes, and benzaldehyde;

[0037] (2) The borohydride reducing agent is one of sodium triacetoxyborohydride, sodium cyanoborohydride, and sodium borohydride;

[0038] (3) The reaction solvent is one of methanol, ethanol, or isopropanol;

[0039] (4) The reaction temperature is 0-30℃ and the reaction time is 0.5-2 hours;

[0040] (5) The molar ratio of compound 4, aldehyde compound, and borohydride is 1:(2.0-3.0):(2.0-3.0).

[0041] In one embodiment, compound 5 is an N-alkyl / cycloalkyl / aryl substituted brominated dihydrobenzoxazine compound.

[0042] The present invention also provides an application of a benzoxazine film-forming resin precursor material, wherein the benzoxazine film-forming resin precursor material is used in a photoresist composition.

[0043] In one embodiment, the benzoxazine film-forming resin precursor material accounts for 10% to 30% of the total solid content of the photoresist composition.

[0044] The beneficial effects of this invention are as follows:

[0045] (1) The present invention selects a shorter reaction route, shortens the reaction route to four steps, eliminates the acetylation protection step, and greatly improves the overall yield, which is conducive to the industrialization process;

[0046] (2) In terms of process control, the present invention controls the reaction through a low-temperature polar solvent system, which makes the reaction highly regioselective, free of difficult-to-separate isomer impurities, and the product has high purity.

[0047] (3) The present invention uses borane-based reducing agents to replace highly toxic lithium aluminum hydride, thus avoiding the safety risk of explosion upon contact with water. No special explosion-proof equipment is required, and no heavy metal reagents are involved in the entire process, making the reaction conditions relatively mild.

[0048] (4) The benzoxazine film-forming resin precursor material prepared by the method of the present invention has high purity and has both high density cross-linking sites and rigid benzoxazine skeleton. When applied to photoresist, it can improve the limiting resolution, reduce the linewidth shrinkage rate at 150°C baking, reduce the dry etching rate and increase the glass transition temperature. Attached Figure Description

[0049] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0050] Figure 1 This is a complete synthetic route diagram of the preparation method in Example 1 of the present invention;

[0051] Figure 2 Compound 4 obtained in Example 1 1 H NMR spectrum. Detailed Implementation

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0053] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0054] As analyzed in the background section of this invention, the existing ordinary benzoxazine resin has problems such as excessively high curing temperature and low crosslinking activity, which limits its application in photoresists. In particular, the low crosslinking activity leads to a slow curing rate under light triggering, resulting in insufficient photoresist sensitivity. In order to solve the above problems, this invention provides a method for preparing benzoxazine film-forming resin precursor materials and their application to meet the performance requirements of existing photoresist materials.

[0055] In one embodiment of the present invention, a method for preparing a benzoxazine film-forming resin precursor material includes the following steps:

[0056] S1. Starting with compound 1, under alkaline conditions in the presence of alkali metal carbonates, compound 2 undergoes nucleophilic substitution and cyclization reactions with haloacetyl halides. After the reaction is completed, compound 2 is obtained by quenching, extraction, and purification.

[0057] The compound 1 is o-aminophenol or o-aminophenol with a group 1 on the benzene ring, wherein the group 1 is one of C1-C6 alkyl, C1-C6 alkoxy, fluorine substituent, chlorine substituent and bromine substituent;

[0058] Compound 2 is a benzoxazine-3(4H)-one compound;

[0059] S2. Compound 2 obtained in step S1 is reacted with N-bromosuccinimide in a polar aprotic solvent to undergo a regioselective electrophilic bromination reaction of the aromatic ring; after the reaction is completed, the compound is quenched, extracted and purified to obtain compound 3.

[0060] Compound 3 is a bromobenzoxazine-3(4H)-one compound with one or two bromine substituents on the benzene ring;

[0061] S3. Compound 3 obtained in step S2 is reacted with a borane-based reducing agent under an inert gas atmosphere to selectively reduce the amide carbonyl group to a methylene group. After the reaction is completed, the compound 4 is obtained by quenching, extraction, and purification.

[0062] Compound 4 is a bromodihydrobenzoxazine compound;

[0063] S4. Compound 4 obtained in step S3 is reacted with an aldehyde compound in the presence of a borohydride reducing agent to undergo a reduction amination reaction. After the reaction is completed, the compound is quenched, extracted, and purified to obtain compound 5, which is the benzoxazine film-forming resin precursor material.

[0064] Compound 5 is an N-substituted brominated dihydrobenzoxazine compound.

[0065] Specifically, attached Figure 1 The complete synthetic route for the preparation method in Example 1 is shown below. In this invention, a four-step linear synthetic route is designed based on differences in reactivity. Specifically, in step S1, the synergistic reactivity of the o-aminophenol bifunctional group (-OH / -NH2) is utilized to achieve one-step ring closure. In step S2, the electron-donating conjugation effect of the O / N group on the benzoxazinone ring is further utilized to achieve specific bromination at the 6-position of the benzene ring. In step S3, the selective reduction characteristic of borane on the amide carbonyl group is utilized to avoid debromination of the aromatic ring. In step S4, the high reactivity of secondary amines with aldehydes is utilized to achieve N-position directional alkylation. Each reaction step achieves site specificity through process parameter control, significantly reducing the content of byproducts, which can be completely removed by simple pulping or recrystallization.

[0066] In summary, the preparation method of benzoxazine film-forming resin precursor material provided by the present invention can prepare benzoxazine film-forming resin precursor material with low curing temperature and high crosslinking activity.

[0067] In one embodiment of the present invention, in step S1, at least one of the following conditions is satisfied:

[0068] (1) The alkali metal carbonate is one of potassium carbonate, sodium carbonate, and cesium carbonate;

[0069] (2) The haloacetyl halide is one of chloroacetyl chloride, bromoacetyl chloride, and iodoacetyl chloride;

[0070] (3) The reaction solvent is one of acetonitrile, tetrahydrofuran, and dichloromethane;

[0071] (4) The reaction temperature is 40-80℃ and the reaction time is 1-4 hours;

[0072] (5) The molar ratio of compound 1, haloacetyl halide, and alkali metal carbonate is 1:(1.1-1.5):(2.5-3.5).

[0073] Specifically, in this invention, the role of alkali metal carbonates is to simultaneously remove the phenolic hydroxyl hydrogen (pKa≈10) and amino hydrogen (pKa≈35) from o-aminophenol, forming a bis-anion intermediate. The basicity of potassium carbonate (pKb≈3.7) is sufficient to fully activate both active sites without excessively removing the α-hydrogen from the haloacetyl halide (pKa≈16), leading to its self-polymerization. Conversely, excessive basicity of sodium hydroxide / potassium hydroxide can trigger the hydrolysis of the haloacetyl halide, while insufficient basicity of organic bases such as triethylamine cannot remove the amino hydrogen. Furthermore, this invention controls the reaction temperature at 40-80℃ because this temperature range is the optimal range for nucleophilic substitution cyclization reactions. Below 40℃, the activation energy for the intramolecular SN2 ring-closing reaction is insufficient, resulting in incomplete cyclization and excessive residual starting material. Above 80℃, the activity of the bis-anion intermediate is too high, leading to polyacylation side reactions with excess haloacetyl halide, generating N,O-diacytized products, resulting in a decrease in yield. Furthermore, the molar ratio control principle of this invention is as follows: 1 molecule of o-aminophenol requires 2 molecules of base to neutralize the 2 molecules of HCl generated by the reaction, while also providing the basicity required for cyclization. Therefore, an excess of 0.5-1.5 eq of base ensures that the reaction is sufficient and complete. An excess of haloacetyl halide is to promote the complete reaction of the double anions. Excessive amount will increase the burden of post-processing and trigger polyacylation side reactions.

[0074] In one embodiment of the present invention, in step S2, at least one of the following conditions is satisfied:

[0075] (1) The polar aprotic solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone;

[0076] (2) The reaction temperature is -5 to 10℃, and the reaction time is 8 to 15 hours;

[0077] (3) The molar ratio of compound 2 to N-bromosuccinimide is 1:(0.8-1.2).

[0078] Specifically, the aprotic polar solvents used in this invention are N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone. In step S2, the reaction is an ionic aromatic ring electrophilic substitution reaction. NBS can generate highly reactive Br in polar aprotic solvents. + Equivalents, not free radical bromine species. Solvents such as DMF have large dipole moments, which can effectively stabilize Br. +Intermediates promote the reaction; in nonpolar solvents (such as dichloromethane and petroleum ether), NBS mainly undergoes radical bromination, with poor selectivity and a large number of polybrominated byproducts. Furthermore, this invention employs low-temperature control in the reaction, with -5-10℃ being crucial for regioselectivity. The 6-position electron cloud density on the benzoxazinone ring is the highest, making it the most thermodynamically stable reaction site, but at high temperatures (>10℃), Br... + The equivalent will simultaneously attack the 8th position, which has the second highest electron cloud density, generating a 6,8-dibromo byproduct; at very low temperatures (<-5℃), Br + Insufficient activity of the equivalent compound leads to reaction stagnation and low conversion rate of raw materials. Furthermore, the principle for controlling the NBS dosage in this invention is as follows: 0.9 eq NBS is the optimal monobromination ratio, at which point the raw material is almost completely converted and dibromination byproducts are relatively minimal; exceeding 1.2 eq easily generates tribrominated impurities, which cannot be separated by conventional purification methods.

[0079] In one embodiment of the present invention, in step S3, at least one of the following conditions is satisfied:

[0080] (1) The borane reducing agent is one of borane dimethyl sulfide complex and borane tetrahydrofuran complex;

[0081] (2) The reaction solvent is one of tetrahydrofuran or 1,4-dioxane;

[0082] (3) The reaction temperature is 50-70℃ and the reaction time is 1-3 hours;

[0083] (4) The molar ratio of compound 3 to borane reducing agent is 1:(2.0-3.0).

[0084] Specifically, the core of step S3 is to reduce the amide carbonyl group (-CON-) to a methylene group (-CH2N-) while completely retaining the bromine atom on the aromatic ring. It should be noted that borane is currently the preferred reducing agent for achieving this selectivity. Specifically, as an electron-deficient Lewis acid, it preferentially coordinates with the electron-rich carbonyl oxygen, activating the carbonyl group and transferring a hydride anion; the C-Br bond on the aromatic ring has low polarity and cannot coordinate with borane, therefore it will not be reduced. Using strong reducing agents such as lithium aluminum hydride would simultaneously break the C-Br bond, while sodium borohydride cannot reduce the amide carbonyl group. This invention selects 50-70℃ for amide reduction because below 50℃, the coordination reaction between borane and the carbonyl group is slow, resulting in incomplete reduction and high residual raw materials; above 70℃, the borane-dimethyl sulfide complex decomposes, the reducing agent is deactivated, and a side reaction of amine-borane complex decomposition occurs. Furthermore, the feeding molar ratio control principle of the present invention is as follows: According to the reaction mechanism, 1 molecule of amide requires 2 molecules of borane to be completely reduced to methylene. Therefore, an excess of 0.5-1 eq of reducing agent ensures complete reaction. If the excess is too large, the quenching reaction will produce a large amount of hydrogen gas, which poses a safety hazard and will also increase boron residue.

[0085] In one embodiment of the present invention, in step S4, at least one of the following conditions is satisfied.

[0086] (1) The aldehyde compound is one of C1-C12 alkyl aldehydes, C3-C8 cycloalkyl aldehydes, and benzaldehyde;

[0087] (2) The borohydride reducing agent is one of sodium triacetoxyborohydride, sodium cyanoborohydride, and sodium borohydride;

[0088] (3) The reaction solvent is one of methanol, ethanol, or isopropanol;

[0089] (4) The reaction temperature is 0-30℃ and the reaction time is 0.5-2 hours;

[0090] (5) The molar ratio of compound 4, aldehyde compound, and borohydride is 1:(2.0-3.0):(2.0-3.0).

[0091] Specifically, sodium triacetoxyborohydride is used in this invention because this step is a reductive amination reaction, which requires two processes: imine intermediate formation and imine reduction. Sodium triacetoxyborohydride is the mildest selective reducing agent, with its reducing activity limited to imine ions (pKa≈7) and unable to reduce aldehyde carbonyl groups (pKa≈17), thus avoiding excessive reduction of aldehydes. Sodium borohydride, with its high reducing activity, would simultaneously reduce both aldehydes and imines, generating a large amount of alcohol byproducts. Sodium cyanoborohydride has moderate reducing activity but introduces cyanide impurities, which does not meet the electronic-grade requirements of photoresist. This invention selects a reaction temperature of 0-30℃ because this is the temperature range within which the imine intermediate is stable. Below 0℃, the imine formation reaction rate is slow and the reaction is incomplete; above 30℃, the imine intermediate is easily decomposed, and the aldehyde undergoes a self-polymerization side reaction, generating polyaldehyde impurities. Furthermore, the excess aldehyde is used to promote the complete conversion of secondary amines to tertiary amines and avoid monosubstituted byproducts; at the same time, the excess aldehyde will not be reduced and can be completely removed by washing with water and distillation.

[0092] In one embodiment of the present invention, compound 5 is an N-alkyl / cycloalkyl / aryl substituted brominated dihydrobenzoxazine compound.

[0093] Specifically, the N-position substituent on compound 5 is used to adjust the resin's solubility (the longer the alkyl group, the better the solubility) and curing properties (aryl substitution can increase the glass transition temperature); other substituents on the benzene ring can further fine-tune the resin's dielectric properties and etching resistance.

[0094] In one embodiment of the present invention, the benzoxazine film-forming resin precursor material is applied to a photoresist composition.

[0095] In one embodiment of the present invention, the benzoxazine film-forming resin precursor material accounts for 10% to 30% of the total solid content of the photoresist composition.

[0096] Specifically, the preferred mass percentage of the benzoxazine film-forming resin precursor material is 10% to 30% of the total solid content of the photoresist composition. When the addition amount is less than 10%, the crosslinking density is easily insufficient, the photoresist pattern is prone to collapse, and the thermal stability decreases. When the addition amount is more than 30%, the crosslinking is excessive, the photoresist is not fully developed, and the sensitivity decreases. A mass percentage of 10% to 30% of the benzoxazine film-forming resin precursor material can achieve a better balance between the photoresist's sensitivity, resolution, and thermal stability.

[0097] The present invention will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed by the present invention. Furthermore, in the following embodiments, unless otherwise specified, the reagents and equipment used are commercially available. If specific processing conditions and methods are not explicitly described in the later embodiments, conditions and methods known in the art can be used for processing.

[0098] Example 1

[0099] Step S1: Using o-aminophenol (compound 1) as the starting material, 36 L of acetonitrile was added to a 100 L stainless steel reactor. Stirring was started, and 11.8 kg (85.2 mol, 3.1 eq) of potassium carbonate and 3.0 kg (27.5 mol, 1.0 eq) of o-aminophenol were added. The system was initially turbid, with an internal temperature of 31 °C. The internal temperature was controlled at 10-30 °C, and 3.726 kg (33.0 mol, 1.2 eq) of chloroacetyl chloride was added dropwise over 65 minutes. After the addition was complete, the external temperature was set to 60 °C, and the reaction was heated for 2 hours until the system turned into a yellow turbid liquid. A sample was taken, and TLC (DCM:MeOH = 20:1) analysis confirmed that compound 1 had completely reacted; the reaction was then terminated.

[0100] Separation and purification steps: The system was cooled to approximately 30°C, the reaction solution was discharged, and the mixture was concentrated under reduced pressure until almost no solvent remained, yielding a yellow solid. 70 L of deionized water was added and the mixture was stirred for 1 hour to dissolve the potassium carbonate solid. The mixture was then filtered. The filter cake was stirred with 15 L of methyl tert-butyl ether for 30 minutes, filtered, washed with methyl tert-butyl ether, and air-dried to obtain a total of 3.1 kg of compound 2 as a yellow solid, with a molar yield of 75.6% and an HPLC purity of 96.2%.

[0101] Step S2: Compound 2: 2H-benzo[b][1,4]oxazine-3(4H)-one was added to a 100L stainless steel reactor with 21L of DMF and 1.05kg (7.0mol, 1.0eq) of Compound 2. The mixture was stirred and dissolved at an internal temperature of 32℃, yielding a clear red liquid. The system was then cooled to an internal temperature of 0-5℃, and 1.128kg (6.3mol, 0.9eq) of NBS was added in batches of approximately 100g at 10-minute intervals, while maintaining the internal temperature below 5℃ during the addition. After the addition was complete, the reaction was maintained at an internal temperature of 0-3℃ for 10 hours, and the system remained a clear red liquid. Samples were taken and analyzed by TLC (PE:EA=5:1). Compound 2 was found to have reacted completely, and the reaction was terminated.

[0102] Separation and purification steps: The reaction solution was slowly added to a 100L reactor pre-filled with 63L of deionized water for quenching, during which the internal temperature rose to 32℃. The quenched system was then cooled to 15℃ and stirred for 4 hours, resulting in the precipitation of a large amount of white solid. This solid was filtered to obtain a reddish-brown solid with a wet weight of 5kg. The aqueous phase was cooled to 5℃ and stirred for another 5 hours, resulting in the precipitation of a solid with a wet weight of 500g. HPLC analysis showed a purity of approximately 60.3%, which was discarded as waste. 5kg of the reddish-brown solid was taken and added to 30L of deionized water. The mixture was heated to 60℃ and stirred for 1 hour, then filtered. The filter cake was dissolved in 15L of DMF heated to 50℃ and filtered while hot. 22.5L of deionized water was slowly added to the filtrate with stirring, resulting in the precipitation of a large amount of solid, which was then exothermicly heated to 45℃. Stir for 30 minutes, filter, wash the filter cake with 10L of DMF-water (volume ratio 2:3), and dry in a vacuum oven at 65℃ for 12 hours to obtain a total of 1.32kg of light red solid compound 3, with a molar yield of 67.0% and an HPLC purity of 95.1%.

[0103] Step S3: Compound 3: 20.6 L of anhydrous THF was added to a 100 L glass reactor, followed by 1.72 kg (7.5 mol, 1.0 eq) of Compound 3. Stirring was started, and argon gas was continuously introduced for protection. The system appeared as a yellow turbidity. The system was cooled to 15 °C, and 1.89 L (18.9 mol, 2.5 eq) of 10 M borane dimethyl sulfide complex was added dropwise over 40 minutes while maintaining an internal temperature of 10-20 °C. After the addition was complete, the external temperature was set to 65 °C, and the reaction was heated for 1.5 hours. Significant gas production was observed, and the yellow turbidity gradually turned into a colorless clear liquid. Samples were taken, and TLC (PE:EA = 3:1) analysis showed that Compound 3 had completely reacted. The reaction was then terminated.

[0104] Separation and purification steps: The system was cooled to 20℃, and 10.3L of methanol was slowly added dropwise to quench the reaction over 2.5 hours, producing a large amount of gas. After quenching, argon gas was passed through and stirred for 2 hours, then concentrated to dryness under reduced pressure. The residue was mixed with 2.6kg of silica gel and packed into a silica gel column (18kg silica gel, 200-300 mesh). First, petroleum ether was used to remove impurities, then petroleum ether:ethyl acetate = 10:1 was used to elute the product. The product fraction was collected, concentrated under reduced pressure, and dried using an oil pump to obtain 1.828kg of a pale yellow liquid. 5L of petroleum ether was added to a 20L five-necked flask, and the mixture was cooled to -35℃ under argon protection. 500g of the above-mentioned column-passed pure product was slowly added dropwise, and the system changed from a colorless clear liquid to a yellow turbid liquid. After the addition was complete, the mixture was kept at -35℃ for 30 minutes, filtered while cold, and washed with 500mL of petroleum ether pre-cooled to -40℃ to obtain a yellow granular solid. Immediately transfer the product to a 5L single-necked flask and pump to constant weight at room temperature using an oil pump, yielding 380g of a pale yellow solid. The remaining 1328g of column chromatography product was crystallized using the same method, yielding 1015g of product. The petroleum ether mother liquor was concentrated and recrystallized by column chromatography, yielding 40g of product. The total yield of compound 4 was 1.435kg, with a molar yield of 86.4% and an HPLC purity of 98.7%.

[0105] Figure 2 For compound 4 1 H NMR spectrum.

[0106] Step S4: Compound 4: 6-Bromo-3,4-dihydro-2H-benzo[b][1,4]oxazine was added to two 20L three-necked flasks, each containing 4L of methanol. Then, 4400g of compound 4 (1.87mol, 1.0eq) was added to each flask. The mixture was kept under argon protection and cooled to 15°C. 337g of n-butyraldehyde (4.67mol, 2.5eq) was added in batches of approximately 50g each, with 5-minute intervals. During this addition, the internal temperature rose to 22°C. Next, 990g of sodium triacetoxyborohydride (4.67mol, 2.5eq) was added in batches of approximately 100g each, with 10-minute intervals. This addition was exothermic and gas-producing; the internal temperature was controlled to not exceed 25°C. After the addition was complete, the reaction was maintained at 10-25°C for 30 minutes until a white turbid liquid was formed. Samples were taken and analyzed by TLC (PE:EA = 3:1). The reaction was terminated after confirming complete reaction of compound 4.

[0107] Separation and purification steps: Combine the reaction solutions from the two reaction flasks, slowly pour into 16 L of deionized water to quench, and extract twice with 12 L of ethyl acetate. Combine the organic phases, wash successively with 10 L of saturated sodium bicarbonate solution and 10 L of saturated brine, and dry overnight with anhydrous sodium sulfate. Filter, concentrate under reduced pressure to dryness, mix the residue with 1.2 kg of silica gel, pack into a silica gel column (8.4 kg of silica gel, 200-300 mesh), elute with pure petroleum ether, collect the product fraction, concentrate under reduced pressure, and obtain a pale yellow liquid compound 5, totaling 807 g, with a molar yield of 79.9%, an overall yield of 35.1% for the four steps, and an HPLC purity of 99.2%.

[0108] Compound 5: 6-bromo-3-butyl-3,4-dihydro-2H-benzo[b][1,4]oxazine structural characterization data: ¹H NMR (400MHz, CDCl3) δ: 6.82 (d, J=8.4Hz, 1H), 6.75 (d, J=2.4Hz, 1H), 6.62 (dd, J=8.4, 2.4Hz, 1H), 4.21 (s, 2H), 3.38 (t, J=7.2Hz, 2H), 2.85 (t, J=7.2Hz, 2H), 1.58–1.48 (m, 2H), 1.38–1.28 (m, 2H), 0.92 (t, J=7.2Hz, 3H). 13 C NMR (100MHz, CDCl3) δ: 145.2, 143.5, 125.8, 118.2, 116.5, 112.3, 64.8, 53.2, 49.5, 29.6, 20.5, 14.0. MS (ESI) m / z: 270.0 [M+H] + , 272.0 [M+2+H] + (Isotope peaks). Among them, the residual metal ions are: Na<10ppb, K<10ppb, Fe<5ppb (ICP-MS detection); 5% thermogravimetric temperature Td: 278℃.

[0109] Example 2

[0110] The difference between Example 2 and Example 1 is as follows:

[0111] Step S1: Compound 1: Chloroacetyl chloride: Potassium carbonate = 1:1.1:2.5, reaction temperature 40℃, reaction time 4 hours;

[0112] Step S2: Compound 2: NBS = 1:0.8, reaction temperature -5℃, reaction time 15 hours; Step S3: Compound 3: Borane dimethyl sulfide = 1:2.0, reaction temperature 50℃, reaction time 3 hours; Step S4: Compound 4: n-Butyraldehyde: Sodium triacetoxyborohydride = 1:2.0:2.0, reaction temperature 0℃, reaction time 2 hours; The remaining operations, separation and purification steps are exactly the same as in Example 1.

[0113] The total molar yield of the four-step process was 30.2%, the HPLC purity of the target product was 98.8%, and the Td of the target product was 275℃.

[0114] Example 3

[0115] The only difference between Example 3 and Example 1 is that n-butyraldehyde in step S4 is replaced with benzaldehyde. The remaining operations, separation and purification steps are exactly the same as in Example 1. The target product obtained is 6-bromo-3-benzyl-3,4-dihydro-2H-benzo[b][1,4]oxazine.

[0116] The total molar yield of the four-step process was 36.5%, the HPLC purity of the target product was 99.0%, and the Td of the target product was 291℃.

[0117] In Examples 1 to 3, (1) the molar yield of the product = (actual molar amount of product / theoretical molar amount of product) × 100%, and the total yield is the product of the molar yields of the four-step reaction; (2) the HPLC purity of the product was determined by an Agilent 1260 high performance liquid chromatograph, wherein the C18 column (150mm × 4.6mm, 5μm), the mobile phase acetonitrile / water = 80:20 (V / V), the flow rate was 1.0mL / min, the detection wavelength was 254nm, and the column temperature was 30℃; (3) the thermal stability Td was determined by a TA Q500 thermogravimetric analyzer, the test conditions were a high-purity nitrogen atmosphere, the heating rate was 10℃ / min, the test range was room temperature to 600℃, and the temperature (Td) corresponding to a 5% loss in sample mass was recorded.

[0118] Test case

[0119] Photoresist formulation (parts by weight): 80 parts of poly(p-hydroxystyrene) film-forming resin, 20 parts of benzoxazine film-forming resin precursor material to be tested, 5 parts of diphenyliodonium hexafluorophosphate photoacid generator, 400 parts of propylene glycol methyl ether acetate solvent, and 0.2 parts of triethanolamine polymerization inhibitor. The precursor material undergoes cross-linking during the baking process after exposure, forming a blended cross-linked resin with poly(p-hydroxystyrene).

[0120] The above components were mixed evenly and filtered through a 0.22 μm microporous membrane to obtain a photoresist solution. The photoresist solution was spin-coated onto a silicon wafer and pre-baked at 110°C for 90 s to obtain a 150 nm thick photoresist film. The film was then exposed using a 248 nm deep ultraviolet irradiation machine and post-baked at 110°C for 90 s. 2.38 wt% tetramethylammonium hydroxide (TMAH) developer was added and developed for 30 s. The film was rinsed with deionized water and dried with nitrogen. The performance of the resulting photoresists was tested, and the results are shown in Table 1.

[0121]

[0122] Table 1

[0123] As can be seen from Table 1 above, the photoresist compositions prepared in Examples 1 to 3, containing the benzoxazine film-forming resin precursor material of the present invention, exhibit superior photoresist sensitivity, limiting resolution, linewidth shrinkage at 150°C baking, dry etching rate, and glass transition temperature. Regarding photoresist sensitivity, the photocrosslinking activity of the product of the present invention is significantly improved, which can greatly reduce the exposure energy consumption of the photolithography process and improve production efficiency. In terms of limiting resolution, the limiting resolution of Examples 1-3 all reach 80nm, which can meet the high-precision patterning requirements of advanced semiconductor processes. Furthermore, the pattern thermal stability... Qualitatively, the relatively low linewidth shrinkage rate of the 150℃ baking in Examples 1-3 indicates that the product of this invention can significantly improve the high-temperature dimensional stability of photoresist patterns and avoid pattern collapse and deformation during post-baking. In terms of etching resistance, the dry etching rate of Examples 1-3 is less than 13.0 nm / min. The lower the dry etching rate, the stronger the etching resistance of the material. The product of this invention can significantly improve the dry etching selectivity of photoresist and ensure effective pattern transfer. In terms of thermal stability, the glass transition temperature of the product of this invention is higher than 175℃, which can meet the high-temperature requirements of advanced photoresist post-baking and etching processes.

[0124] Test results show that the preparation method of benzoxazine film-forming resin precursor material provided by the present invention can prepare products with low curing temperature, high crosslinking activity, and both high density of crosslinking sites and rigid framework. Its application in photoresist is beneficial to improving the resolution, thermal stability and etching resistance of photoresist, and has broad application prospects in high-end semiconductor manufacturing processes.

[0125] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for preparing a benzoxazine film-forming resin precursor material, characterized in that, Includes the following steps: S1. Starting with compound 1, under alkaline conditions in the presence of alkali metal carbonates, compound 2 undergoes nucleophilic substitution and cyclization reactions with haloacetyl halides. After the reaction is completed, compound 2 is obtained by quenching, extraction, and purification. The compound 1 is o-aminophenol or o-aminophenol with a group 1 on the benzene ring, wherein the group 1 is one of C1-C6 alkyl, C1-C6 alkoxy, fluorine substituent, chlorine substituent and bromine substituent; Compound 2 is a benzoxazine-3(4H)-one compound; S2. Compound 2 obtained in step S1 is reacted with N-bromosuccinimide in a polar aprotic solvent to undergo a regioselective electrophilic bromination reaction of the aromatic ring; after the reaction is completed, the compound is quenched, extracted and purified to obtain compound 3. Compound 3 is a bromobenzoxazine-3(4H)-one compound with one or two bromine substituents on the benzene ring; S3. Compound 3 obtained in step S2 is reacted with a borane-based reducing agent under an inert gas atmosphere to selectively reduce the amide carbonyl group to a methylene group. After the reaction is completed, the compound 4 is obtained by quenching, extraction, and purification. Compound 4 is a bromodihydrobenzoxazine compound; S4. Compound 4 obtained in step S3 is reacted with an aldehyde compound in the presence of a borohydride reducing agent to undergo a reduction amination reaction. After the reaction is completed, the compound is quenched, extracted, and purified to obtain compound 5, which is the benzoxazine film-forming resin precursor material. Compound 5 is an N-substituted brominated dihydrobenzoxazine compound.

2. The method for preparing the benzoxazine film-forming resin precursor material according to claim 1, characterized in that, In step S1, at least one of the following conditions must be met: (1) The alkali metal carbonate is one of potassium carbonate, sodium carbonate, and cesium carbonate; (2) The haloacetyl halide is one of chloroacetyl chloride, bromoacetyl chloride, and iodoacetyl chloride; (3) The reaction solvent is one of acetonitrile, tetrahydrofuran, and dichloromethane; (4) The reaction temperature is 40-80℃ and the reaction time is 1-4 hours; (5) The molar ratio of compound 1, haloacetyl halide, and alkali metal carbonate is 1:(1.1-1.5):(2.5-3.5).

3. The method for preparing the benzoxazine film-forming resin precursor material according to claim 1, characterized in that, In step S2, at least one of the following conditions must be met: (1) The polar aprotic solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; (2) The reaction temperature is -5 to 10℃, and the reaction time is 8 to 15 hours; (3) The molar ratio of compound 2 to N-bromosuccinimide is 1:(0.8-1.2).

4. The method for preparing the benzoxazine film-forming resin precursor material according to claim 1, characterized in that, In step S3, at least one of the following conditions must be met: (1) The borane reducing agent is one of borane dimethyl sulfide complex and borane tetrahydrofuran complex; (2) The reaction solvent is one of tetrahydrofuran or 1,4-dioxane; (3) The reaction temperature is 50-70℃ and the reaction time is 1-3 hours; (4) The molar ratio of compound 3 to borane reducing agent is 1:(2.0-3.0).

5. The method for preparing the benzoxazine film-forming resin precursor material according to claim 1, characterized in that, In step S4, at least one of the following conditions must be met: (1) The aldehyde compounds are C1-C 12 One of alkyl aldehydes, C3-C8 cycloalkyl aldehydes, and benzaldehyde; (2) The borohydride reducing agent is one of sodium triacetoxyborohydride, sodium cyanoborohydride, and sodium borohydride; (3) The reaction solvent is one of methanol, ethanol, or isopropanol; (4) The reaction temperature is 0-30℃ and the reaction time is 0.5-2 hours; (5) The molar ratio of compound 4, aldehyde compound, and borohydride is 1:(2.0-3.0):(2.0-3.0).

6. The application of the benzoxazine film-forming resin precursor material prepared by the method of claim 1, characterized in that, The benzoxazine film-forming resin precursor material is used in the photoresist composition.

7. The application according to claim 6, characterized in that, In the photoresist composition, the benzoxazine film-forming resin precursor material accounts for 10% to 30% of the total solid content of the photoresist composition by mass.

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