Camphorsulfonate-based flavone photoacid generator and preparation method thereof

Abstract

The application discloses a camphorsulfonate-based flavone photoacid generator and a preparation method thereof. 16 fatty alkyl, C1-C 16 fatty alkoxy, dimethylamino or phenyl. The camphorsulfonate-based flavone photoacid generator prepared by the application realizes long-wave absorption based on a flavone nucleus, has strong absorption to 248nm and 365nm UV LED light sources, and has high photosensitivity. The camphorsulfonate-based flavone photoacid generator contains a camphorsulfonate group which is directly connected with a flavone aromatic ring. The structure has photosensitive cleavage characteristics, and strong acid camphorsulfonic acid is generated by photolysis. Because the van der Waals volume of camphorsulfonic acid is large, the diffusion of camphorsulfonic acid is slow, and therefore the diffusion in a resin matrix is poor, so that better resolution and line edge roughness can be obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of photoresists, and the substrate relates to a camphorsulfonate flavonoid photoacid generator and a preparation method thereof. Background Art

[0002] Photoresist, also known as photoresist, is a type of etch-resistant thin film material whose solubility changes when exposed to light sources such as ultraviolet light, excimer lasers, X-rays, electron beams, and ion beams. It is primarily used in the processing of integrated circuits and discrete semiconductor devices in the electronics industry. It also has a wide range of applications in the manufacturing of flat-panel displays, light-emitting diodes, flip-chip packages, magnetic heads, and precision sensors.

[0003] Chemically amplified photoresist systems were first proposed in the 1980s by Ito et al. at IBM's Almanden Research Center. Chemical amplification involves adding a photoacid generator to a photosensitive composition. Upon exposure to light, a photochemical reaction with a quantum efficiency no greater than 1 occurs, producing a chemical amplifier, such as a proton acid or Lewis acid. After the light ceases, this chemical amplifier acts as a catalyst for the polymer's chemical reactions, causing further chemical reactions through heating or hydrolysis, achieving amplification and significantly increasing the initial photochemical quantum efficiency. Therefore, photoacid generators play a crucial role in chemically amplified photoresist systems.

[0004] Photoacid generators (PAGs) are compounds that decompose to produce specific acids when exposed to radiation, such as light, radiation, or plasma. The resulting acid can decompose or crosslink acid-sensitive resins, thereby increasing the dissolution contrast between the illuminated and non-illuminated areas. Due to their excellent chemical amplification effect, high imaging sensitivity, and recording accuracy, PAG systems are widely used in imaging systems such as cationic photocurable materials, thermal printing plates, and chemically amplified resists. A photoacid generator is a key component of chemically amplified photoresists. Its structure and properties significantly influence the image formed by the photoresist system. It should exhibit good chemical and thermal stability, as well as high acid generation efficiency.

[0005] At present, sulfonium salts and sulfonate photoacid generators have a dominant position among photoacid generators due to their excellent solubility in matrix resins. Sulfonate acid generators appeared relatively late. The sulfonate compounds reported in the literature as acid generators for resist systems mainly include: N-toluenesulfonyloxyphthalimide, N-trifluoromethanesulfonyloxysuccinimide, N-trifluoromethanesulfonylnaphthalimide, dinitrobenzyl p-toluenesulfonate and p-toluenesulfonic acid of α-hydroxymethylbenzoin. However, most of these substances generate trifluoromethanesulfonic acid (79A) with a smaller van der Waals volume in the reaction. 3 ), p-toluenesulfonic acid (137A 3 ) and other substances, which makes them easy to diffuse in the resin matrix and thus increases the line edge roughness. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide a camphorsulfonate flavonoid photoacid generator and a preparation method thereof. The camphorsulfonate flavonoid photoacid generator prepared by the present invention can be photolyzed to generate a flavonoid with a van der Waals volume of 193A. 3 camphorsulfonic acid, thereby making it diffuse slowly in the photoresist and being able to obtain better line edge roughness; in addition, the camphorsulfonic acid ester flavonoid photoacid generator prepared by the present invention has the characteristic of strong thermal stability.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] The first object of the present invention is to provide a camphorsulfonate flavonoid photoacid generator, the chemical formula of which is wherein R is selected from H, halogen, C1-C 16 Fatty alkyl, C1-C 16 Fatty alkoxy, dimethylamino or phenyl.

[0009] The above-mentioned camphorsulfonate flavonoid photoacid generator absorbs light based on the flavonoid mother nucleus, and the flavonoid derivative has a high efficiency in initiating monomer polymerization. By introducing the camphorsulfonate group, the photoinitiator is given acid-generating properties, and photolysis generates a strong acid - camphorsulfonic acid. The generated acid can cause the acid-sensitive resin to decompose or cross-link, thereby increasing the dissolution contrast between the illuminated part and the non-illuminated part or continuing the catalytic reaction. This new photoinitiator contains a camphorsulfonate group, which is directly connected to the flavonoid structure. The structure has photosensitive cleavage characteristics and photolysis generates a strong acid camphorsulfonic acid. The van der Waals volume of the generated camphorsulfonic acid is 193A 3 , which is larger than the common trifluoromethanesulfonic acid (79A 3 ), p-toluenesulfonic acid (137A 3 ) and other substances, so they diffuse more slowly in the resin matrix.

[0010] Preferably, the camphorsulfonate flavonoid photoacid generator is 2-(4-(dimethylamino)phenyl)-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate, 2-(4-methylphenyl)-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate or 2-(4-fluorophenyl)-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate.

[0011] The second object of the present invention is to provide a method for preparing the camphorsulfonate flavonoid photoacid generator as described in the first object, comprising the following steps:

[0012] (1) 2-Hydroxyacetophenone and The flavonol compounds were synthesized by the Algar-Flynn-Oyamada method; Where R is selected from H, halogen, C1-C 16 Fatty alkyl, C1-C 16 Fatty alkoxy, dimethylamino or phenyl; preferably, the 2-hydroxyacetophenone and The feeding molar ratio is (1.0-3.0);

[0013] (2) Reacting the flavonol compound with camphorsulfonyl chloride or camphorsulfonyl fluoride to prepare a camphorsulfonate flavonol photoacid generator. The specific process is as follows:

[0014] A flavonol compound is dissolved in a solvent, and then a weak alkaline substance is added to obtain a reaction solution; camphorsulfonyl chloride or camphorsulfonyl fluoride is added to the reaction solution under ice-salt bath conditions to react, and after the reaction is completed, the impurities and solvent are removed in sequence to obtain a camphorsulfonate flavonoid photoacid generator. Further preferably, the molar ratio of the flavonol compound to camphorsulfonyl chloride or camphorsulfonyl fluoride is 1:(1.5-5.0). The temperature of the ice-salt bath is -10 to 0°C; the weak alkaline substance is triethylamine, pyridine or potassium carbonate; and the solvent is dichloromethane, tetrahydrofuran, acetonitrile, dimethyl sulfoxide, tetrahydrofuran, chloroform or N,N-dimethylformamide.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The camphorsulfonate flavonoid photoacid generator prepared by the present invention achieves long-wave absorption based on the flavonoid mother nucleus, has strong absorption to 248nm and 365nm UV LED light sources, and has high sensitivity. It contains a camphorsulfonate group and is directly connected to the flavonoid aromatic ring. This structure has photosensitive cracking characteristics and produces strong acid camphorsulfonic acid upon photolysis. Because camphorsulfonic acid has a large van der Waals volume, then according to Einstein's diffusion law, the diffusion rate of a substance molecule in a solution or gas can be expressed by the following formula: D=kBT / 6πηr, where D is the diffusion coefficient, k is the Boltzmann constant, B is the temperature, T is the time, η is the viscosity of the solution or gas, and r is the radius of the molecule. Since the molecular radius r is positively correlated with its van der Waals volume, it can be seen from this that the large volume of acid generated has poor diffusivity in the resin matrix. Suppressing the diffusion of the generated acid is the key to achieving better resolution and line edge roughness. Therefore, the camphorsulfonate flavonoid photoacid generator prepared by the present invention has good resolution and line edge roughness. In addition, the product prepared by the method of the present invention has good thermal stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 2-(4-methylphenyl)-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate prepared in Example 1 1 HNMR spectrum;

[0018] Figure 2 2-4-Fluorophenyl-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate prepared in Example 2 1 HNMR spectrum. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to the embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0020] In addition, unless otherwise specified, the preparation processes in the following examples are all conventional means in the prior art in the art, and therefore, they are not described in detail; the parts in the following embodiments are all parts by weight.

[0021] Example 1

[0022] The synthesis method of 2-(4-methylphenyl)-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate is shown in the following formula:

[0023]

[0024] The preparation steps are as follows:

[0025] In a 500-mL round-bottom flask, add 12 g of sodium hydroxide and 30 mL of water, mix and dissolve to obtain a sodium hydroxide aqueous solution. After the sodium hydroxide aqueous solution cools to room temperature, add 20 mL of ethanol and mix thoroughly. Dissolve 4.86 g of 2-hydroxyacetophenone and 5.33 g of 4-methylbenzaldehyde in 70 mL of ethanol to obtain a mixed solution. First, add half of the mixed solution dropwise to the round-bottom flask. After 30 minutes, add the remaining half to obtain a reaction solution. The round-bottom flask is placed at 50°C and incubated until the reactants dissolve. After reacting for 12 hours, 12 mL of H₂O₂ is added and the reaction is continued for another 12 hours. After TLC detection of the starting material spot, adjust the solution pH to 7 with dilute hydrochloric acid and filter to obtain the crude product. The crude product is recrystallized from an ethanol / water mixture (ethanol:water volume ratio 1:1) to obtain 2-(4-methylphenyl)-3-hydroxy-4H-benzofuran-4-one.

[0026] 2 g of 2-(4-methylphenyl)-3-hydroxy-4H-benzofuran-4-one and 30 mL of dichloromethane were added to a 100 ml round-bottom flask and dissolved therein, followed by the addition of 1.0 g of triethylamine to obtain a reaction solution. 4.21 g of camphorsulfonyl chloride was slowly added dropwise to the round-bottom flask in an ice-salt bath (-10 to 0° C.) to react with the reaction solution. TLC was performed until the starting material spot disappeared. Water was added to the round-bottom flask to remove water-soluble impurities, and the solvent was then removed by rotary evaporation. 3.13 g of 2-4-methylphenyl-4-oxo-4H-benzofuran-3-ylbenzenesulfonate was obtained by column chromatography with a yield of 80%.

[0027] Figure 1 2-(4-methylphenyl)-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate prepared in Example 1 1 HNMR spectrum, 1H NMR (400MHz, CDCl3) δ8.28 (dd, 1H, J = 8 Hz), 7.97 (d, 2H, J = 8 Hz), 7.74 (m, 1H), 7.58 (d, 1H, J = 8.4 Hz), 7.47 (t, 1H, J = 8 Hz), 7.36 (d, 2H, J = 8.4 Hz), 4.23 (d, 1H, J = 15.2 Hz), 4.13 (d, 1H, J = 15.2 Hz), 2.5 0-2.40(m,5H),2.13(t,1H,J=4Hz),2.11-2.02(m,1H),1.97(d,1H,J=18.4),1.78(ddd,1H,J1=14 Hz, J2=9.6Hz, J3=4.8), 1.45(ddd,1H, J1=12.8Hz, J2=10.4Hz, J3=4Hz), 1.17(s,3H)0.98(s,3H).

[0028] Example 2

[0029] The synthesis method of 2-(4-fluorophenyl)-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate, the synthesis process is shown in the following formula:

[0030]

[0031] The preparation steps are as follows:

[0032] In a 500-mL round-bottom flask, add 12 g of sodium hydroxide and 30 mL of water, mix and dissolve to obtain a sodium hydroxide aqueous solution. After the sodium hydroxide aqueous solution cools to room temperature, add 20 mL of ethanol and mix thoroughly. Dissolve 4.86 g of 2-hydroxyacetophenone and 4.34 g of 4-fluorophenylbenzaldehyde in 70 mL of ethanol to obtain a mixed solution. First, add half of the mixed solution dropwise to the round-bottom flask. After 30 minutes, add the remaining half to obtain a reaction solution. The round-bottom flask is placed at 50°C and incubated until the reactants dissolve. After reacting for 12 hours, 12 mL of H₂O₂ is added and the reaction is continued for another 12 hours. After TLC detection of the starting material spot, adjust the solution to pH 7 with dilute hydrochloric acid and filter to obtain the crude product. The crude product is recrystallized from an ethanol / water mixture (ethanol:water volume ratio 1:1) to obtain 2-4-fluorophenyl-3-hydroxy-4H-benzofuran-4-one.

[0033] 2 g of 2-4-fluorophenyl-3-hydroxy-4H-benzofuran-4-one and 30 mL of dichloromethane were added to a 100 ml round-bottom flask and dissolved therein, followed by the addition of 1.0 g of triethylamine to obtain a reaction solution. 4.13 g of camphorsulfonyl chloride was slowly added dropwise to the round-bottom flask in an ice-salt bath (-10 to 0° C.) to react with the reaction solution. TLC was performed until the raw material spot disappeared. Water was added to the round-bottom flask to remove water-soluble impurities, and the solvent was then removed by rotary evaporation. 3.03 g of 2-4-fluorophenyl-4-oxo-4H-benzofuran-3-yl camphorsulfonate was obtained by column chromatography with a yield of 78%.

[0034] Figure 2 2-4-Fluorophenyl-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate prepared in Example 2 1HNMR spectrum, 1H NMR (400MHz, CDCl3) δ8.29 (d, 1H, J = 8 Hz), 7.96 (d, 2H, J = 8.4 Hz), 7.77 (ddd, 1H, J1 = 8.4 Hz, J2 = 7.2 Hz, J3 = 1.6 Hz), 7.70 (d, 2H, J = 8.8 Hz), 7.58 (d, 1H, J = 8.4 Hz), 7.48 (t, 1H, J = 8 Hz), 4.26 (d, 1H, J = 15.2 Hz), 4.15 (d, 1H, J =14.8Hz),2.49-2.40(m,2H),2.15(t,1H,J=4.4Hz),2.13-2.03(m,1H),1.98(d,1H,J=18.4Hz),1.79(ddd,1 H, J1=14Hz, J2=9.6Hz, J3=4.8Hz), 1.46 (ddd, 1H, J1=12.8Hz, J2=9.6Hz, J3=4Hz), 1.17 (s, 3H), 0.99 (s, 3H).

[0035] Thermal stability test

[0036] The thermal stability of the products prepared in the above examples was characterized using a DTG-60AH thermogravimetric analyzer (Shimadzu). Specifically, the temperature was increased from 30°C to 600°C at a rate of 10°C / min under a nitrogen atmosphere at a flow rate of 50 mL / min.

[0037] Taking the temperature of 95% retention rate as the thermal decomposition temperature, the thermal decomposition temperature of 2-(4-methylphenyl)-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate prepared in Example 1 is 264°C; the thermal decomposition temperature of 2-4-fluorophenyl-4-oxo-4H-benzofuran-3-yl camphorsulfonate prepared in Example 2 is 249°C. The thermal decomposition temperature of the currently commonly used 1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl trifluoromethanesulfonate is 225°C, and the thermal decomposition temperature of 2,6-dinitrobenzyl 4-methylbenzenesulfonate is 216°C. By comparison, it can be seen that the products prepared by the method of the present invention have better thermal stability.

[0038] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

Claims

1. A camphorsulfonate flavonoid photoacid generator, characterized in that: The chemical structural formula of the camphorsulfonate flavonoid photoacid generator is , wherein R is selected from H, halogen, C1-C 16 Fatty alkyl, C1-C 16 Fatty alkoxy, dimethylamino or phenyl.

2. The camphorsulfonate flavonoid photoacid generator according to claim 1, characterized in that: The camphorsulfonate flavonoid photoacid generator is 2-(4-(dimethylamino)phenyl)-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate, 2-(4-methylphenyl)-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate or 2-(4-fluorophenyl)-4-oxo-4H-benzofuran-3-ylbenzene camphorsulfonate.

3. The method for preparing the camphorsulfonate flavonoid photoacid generator according to claim 1, wherein: The following steps are involved: (1) 2-Hydroxyacetophenone and The flavonol compounds were synthesized by the Algar-Flynn-Oyamada method; Where R is selected from H, halogen, C1-C 16 Fatty alkyl, C1-C 16 Fatty alkoxy, dimethylamino or phenyl; (2) The flavonol compound is reacted with camphorsulfonyl chloride or camphorsulfonyl fluoride to prepare a camphorsulfonate-based flavonol photoacid generator.

4. The method for preparing the camphorsulfonate flavonoid photoacid generator according to claim 3, wherein: The specific process of step (2) is as follows: dissolving the flavonol compound in a solvent, and then adding a weak alkaline substance to obtain a reaction solution; adding camphorsulfonyl chloride or camphorsulfonyl fluoride to the reaction solution under ice-salt bath conditions to react, and after the reaction is completed, removing impurities and removing the solvent in sequence to obtain a camphorsulfonate flavonoid photoacid generator.

5. The method for preparing the camphorsulfonate flavonoid photoacid generator according to claim 4, wherein: The molar ratio of the flavonol compound to camphorsulfonyl chloride or camphorsulfonyl fluoride is 1:(1.5-5.0).

6. The method for preparing the camphorsulfonate flavonoid photoacid generator according to claim 4, wherein: The temperature of the ice-salt bath is -10~0°C.

7. The method for preparing the camphorsulfonate flavonoid photoacid generator according to claim 4, wherein: The weakly alkaline substance is triethylamine, pyridine or potassium carbonate.

8. The method for preparing the camphorsulfonate flavonoid photoacid generator according to claim 4, wherein: The solvent is dichloromethane, tetrahydrofuran, acetonitrile, dimethyl sulfoxide, tetrahydrofuran, chloroform or N,N-dimethylformamide.

Images