High refractive index calixarene derivative photoresist and preparation method and application thereof

Abstract

The present disclosure provides a high refractive index calixarene derivative photoresist and a preparation method and application thereof. The photoresist comprises a solvent and a main component, which is a calixarene derivative molecule containing a diazonaphthoquinone group and a sulfide structure. The photoresist of the present disclosure has the characteristics of high resolution, high refractive index and high corrosion resistance, and is suitable for use in immersion lithography technology.

Description

Technical Field

[0001] This disclosure relates to the field of photoresist technology, specifically to a high-refractive-index calixarene derivative photoresist, its preparation method, and its application. Background Technology

[0002] In photolithography, resolution improvements are typically achieved by shortening the exposure wavelength and increasing the numerical aperture (NA) of the optical system. However, as the performance requirements of semiconductor devices increase, the critical dimensions of lithographic patterns are shrinking, leading to a sharp increase in the cost and complexity of the light source and optical system. Research has found that replacing air with a high-refractive-index fluid such as water as the medium between the lithography lens and the photoresist is equivalent to increasing the lens's NA and depth-of-focus ratio, thereby improving resolution. For example, the 193nm immersion lithography technology developed based on this principle is currently the mainstay of advanced integrated circuit (IC) chip manufacturing. Furthermore, in non-IC applications and research fields, using immersion lithography with relatively long-wavelength light sources (wavelengths above 193nm) to replace expensive short-wavelength, high-energy exposure equipment to improve lithographic resolution also shows considerable promise.

[0003] In immersion lithography at a given wavelength, the choice of immersion solution is one of the key factors determining resolution. Pure water, with its high refractive index (n=1.33), high transparency, environmental friendliness, low cost, and low corrosivity, is the preferred immersion medium and the first-generation immersion solution. Researchers have subsequently developed second-generation immersion solutions based on aqueous solutions of water-soluble organic molecules and inorganic salts, achieving refractive indices above 1.55; and third-generation immersion solutions based on borates, organosilanes, and alkane compounds, with an even higher n value of 1.8, which promises to significantly improve the limiting resolution.

[0004] However, traditional photoresist resins, especially those used in the near-ultraviolet to deep ultraviolet bands (wavelengths above 193nm), such as i-line, g-line, and KrF photoresist resins, generally have a refractive index of no more than 1.6. Immersing these resins in liquids with higher refractive indices not only fails to effectively improve the overall n-value of the system but may also lead to a decrease in exposure quality and exposure margin. Furthermore, the compatibility between the photoresist material and the complex composition of high-n-value immersion solutions is also a potential problem. For example, traditional chemically amplified photoresists may experience photoacid loss or even partial dissolution of the film upon contact with organic immersion solutions. Finally, even with a significant improvement in exposure resolution, the inherent resolution of traditional ultraviolet photoresists will remain a major factor limiting pattern quality.

[0005] Therefore, to improve photolithography resolution by utilizing light sources with wavelengths above 193nm and high n-value immersion solutions, it is necessary to develop new photoresist materials with high resolution, high refractive index, and high corrosion resistance. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] To address the aforementioned issues, this disclosure provides a high-refractive-index calixarene derivative photoresist, its preparation method, and its application, which solves the problems of low refractive index, insufficient resolution, and poor corrosion resistance that exist in traditional photoresists used in immersion lithography.

[0008] (II) Technical Solution

[0009] This disclosure provides a high-refractive-index calixarene derivative photoresist, comprising: a solvent; and a main component, which is a calixarene derivative molecule containing a diazonoquinone group and a thioether structure.

[0010] Furthermore, the structure of the main component is shown in Equation I below:

[0011]

[0012] Among them, R 1 It is an aliphatic or aromatic group with 1 to 20 carbon atoms; R 2 R is a diazonoquinone group or hydroxyl group. 2 At least part of it is a diazonoquinone group; n = 1 to 4.

[0013] Furthermore, R 1 It contains one or more of the following substituents: hydroxyl group, carboxyl group, epoxy group, ether, thioether, ester group, and amide group; preferably, R 1 It is a straight-chain alkane, containing 1 to 5 carbon atoms.

[0014] Furthermore, the structure of the main component is shown in Equation II below:

[0015]

[0016] Among them, R 2 R is a diazonoquinone group or hydroxyl group. 2 At least partially composed of a diazonoquinone group; R 3 It is a linear alkane chain; R 4 It consists of aliphatic or aromatic groups with 1 to 20 carbon atoms; n = 1 to 4.

[0017] Furthermore, R 3 It contains one or more of the following substituents: hydroxyl, carboxyl, epoxy, ether, thioether, ester, amide, and aryl; R 4It contains one or more of the following substituents: hydroxyl group, carboxyl group, epoxy group, ether, thioether, ester group, and amide group; preferably, R 3 It is a straight-chain alkane, containing 1 to 5 carbon atoms; R 4 It is a straight-chain alkane, containing 1 to 6 carbon atoms.

[0018] Furthermore, the diazonoquinone group is One of them; the grafting rate of the diazonoquinone group in the main component is 45% to 65%; n = 1 or 2.

[0019] Furthermore, the solvent includes one or more of the following: n-butyl acetate, ethyl acetate, γ-butyrolactone, propylene glycol methyl ether acetate, propylene glycol methyl ether, and methyl isobutyl ketone; the mass of the solvent is 85% to 98% of the mass of the calixarene derivative photoresist.

[0020] This disclosure also provides a method for preparing a high-refractive-index calixarene derivative photoresist according to the aforementioned method, comprising: S11, adding concentrated hydrochloric acid to a resorcinol solution under ice bath conditions, then adding a sulfur-containing alkyl aldehyde or aryl aldehyde dropwise, gradually increasing the temperature to allow the sulfur-containing alkyl aldehyde or aryl aldehyde to react with the resorcinol, and washing and drying to obtain a calixarene derivative molecule containing a thioether structure; S12, dissolving the product obtained in S11, adding triethylamine under ice bath conditions, then adding a sulfonyl chloride containing a diazononaphthoquinone group dropwise to react, and purifying to obtain a calixarene derivative molecule containing a diazononaphthoquinone group and a thioether structure; S13, dissolving the product obtained in S12 in a solvent to obtain a high-refractive-index calixarene derivative photoresist.

[0021] This disclosure also provides a method for preparing the aforementioned high-refractive-index calixarene derivative photoresist, comprising: S21, adding concentrated hydrochloric acid to a resorcinol solution under ice bath conditions, then adding alkyl aldehyde or aryl aldehyde dropwise, gradually increasing the temperature to allow the alkyl aldehyde or aryl aldehyde to react with resorcinol, and washing and drying to obtain calixarene derivative molecules; S22, dissolving the product obtained in S21, adding ethanethiol, triethylamine and formaldehyde sequentially, and heating to react to obtain calixarene derivative molecules containing a thioether structure; S23, dissolving the product obtained in S22, adding triethylamine under ice bath conditions, then adding sulfonyl chloride containing a diazononaphthoquinone group dropwise to react, and purifying to obtain calixarene derivative molecules containing a diazononaphthoquinone group and a thioether structure; S24, dissolving the product obtained in S23 in a solvent to obtain a high-refractive-index calixarene derivative photoresist.

[0022] This disclosure also provides an application of the aforementioned high-refractive-index calixarene derivative photoresist in immersion imaging lithography and immersion interference lithography in the near-ultraviolet to deep ultraviolet bands.

[0023] (III) Beneficial Effects

[0024] This disclosure presents a high-refractive-index calixarene derivative photoresist and its preparation method. By introducing a sulfide structure, the refractive index of the photoresist is improved. The introduction of a diazonoquinone group helps to improve contrast. At the same time, the functional groups (sulfide structure and diazonoquinone group) are simultaneously linked to the uniform molecular glass framework of calixarene molecules. The molecules are small in size and do not have problems such as aggregation or entanglement, thus having higher resolution potential. This photoresist adopts a new molecular structure and a non-chemically amplified photosensitive mechanism, does not produce photoacids, does not dissolve in a variety of high-refractive-index immersion solutions, and has good corrosion resistance. When used in combination with high-refractive-index immersion solutions, it can significantly improve the resolution of photolithography. Attached Figure Description

[0025] Figure 1 A flowchart illustrating a method for preparing a first high-refractive-index calixarene derivative photoresist according to an embodiment of the present disclosure is shown.

[0026] Figure 2 A flowchart illustrating a second method for preparing a high-refractive-index calixarene derivative photoresist according to an embodiment of this disclosure is shown schematically.

[0027] Figure 3 A schematic diagram illustrating the process of a first method for preparing a main component according to an embodiment of the present disclosure is shown.

[0028] Figure 4 The schematic diagram illustrates a flow chart of a second main component preparation method according to an embodiment of the present disclosure;

[0029] Figure 5 The grating pattern obtained according to Embodiment 1 of this disclosure is illustrated schematically;

[0030] Figure 6 The raster pattern obtained according to Comparative Example 1 of this disclosure is schematically shown;

[0031] Figure 7 The raster pattern obtained according to Comparative Example 2 of this disclosure is schematically shown;

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Resorcinol; 2. 3-Methylthiopropional; 3. First sulfur-containing calixarene; 4. First main component; 5. Triacetaldehyde; 6. Caxarene; 7. Second sulfur-containing calixarene; 8. Second main component. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0035] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0036] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0037] In existing photolithography technologies, utilizing light sources with wavelengths above 193 nm in conjunction with high-refractive-index immersion solutions shows considerable promise for improving lithographic resolution. However, traditional photoresist resins typically have low refractive indices, making it difficult to match with immersion solutions that have higher refractive indices than water. For traditional chemically amplified photoresist systems, contact between the photoresist and organic immersion solutions can lead to the loss of photoacids and even partial dissolution of the film. While using high-refractive-index immersion solutions can significantly improve optical field resolution, the actual quality of the lithographic pattern may be limited by the resolution level of the traditional ultraviolet photoresist itself. To address these issues, this disclosure provides a high-refractive-index calixarene derivative photoresist and its preparation method. This photoresist not only has a refractive index close to that of high-n-value immersion solutions but also possesses a sufficiently high resolution level and is resistant to the corrosive effects of the immersion solution.

[0038] This disclosure provides a high-refractive-index calixarene derivative photoresist, comprising: a solvent; and a main component, which is a calixarene derivative molecule containing a diazonoquinone group (DNo) and a thioether structure.

[0039] In the main molecule of the photoresist, diazonaquinone graft groups and thioether side groups are introduced simultaneously. The thioether side groups are used to improve the refractive index of the photoresist. The refractive index of traditional phenolic resin-type photoresists and poly(p-hydroxystyrene) chemical amplification photoresists is usually below 1.6, while the refractive index of the photoresist disclosed in this invention can reach above 1.7. The diazonaquinone graft groups are used to improve the contrast of the photoresist. At the same time, the functional groups (thioether structure and diazonaquinone group) are simultaneously connected to the highly uniform molecular weight calixarene molecular glass framework. Compared with traditional polymer-type photoresists, the photoresist disclosed in this invention has a small molecular volume and does not have problems such as aggregation and entanglement. It has higher resolution potential, and the resolution (defined as half a period of dense grating pattern) can reach 60 nm. On the other hand, in traditional chemical amplification systems, photoacids are easily leached out in aqueous immersion solutions, and this effect may be more pronounced in oily matching solutions with higher refractive indices (such as alicyclic and halogenated aromatic compounds). As a result, the exposed pattern is prone to defects or even missing parts. The photoresist molecules proposed in this disclosure adopt a new molecular structure and a non-chemical amplification photosensitive mechanism, do not produce photoacids, and do not dissolve in a variety of high refractive index matching solutions. They have good corrosion resistance and can significantly improve the resolution of photolithography when used in combination with high refractive index immersion solutions.

[0040] Based on the above embodiments, one structure of the main component is shown in Formula I:

[0041]

[0042] Among them, R 1 R is an aliphatic or aromatic group with 1 to 20 carbon atoms. 1 It may contain any one or more of the following as substituents: alcohol hydroxyl group, carboxyl group, epoxy group, ether, thioether, ester group, and amide group; preferably, R 1 It is a straight-chain alkane, containing 1 to 5 carbon atoms.

[0043] R 2 R2 is a diazononaphthoquinone group or a hydroxyl group, and at least part of it is a diazononaphthoquinone group, with a structure such as... One of them, wherein the grafting rate of the diazonoquinone group in the main component is 45% to 65%. n = 1 to 4, preferably n = 1 or 2.

[0044] Based on the above embodiments, another structure of the main component is shown in Formula II below:

[0045]

[0046] Among them, R 2 R is a diazonoquinone group or hydroxyl group. 2 At least part of it is a diazonoquinone group, and its structure is, for example, as follows: One of the components, wherein the grafting rate of the diazonoquinone group in the main component is 45% to 65%. A grafting rate of the diazonoquinone group within this range provides good photolithographic performance; too low a grafting rate leads to poor film retention, while too high a grafting rate leads to poor adhesion. n = 1 to 4, preferably n = 1 or 2.

[0047] R 3 For linear alkane chains, R 3 It may contain any one or more of the following as substituents: alcohol hydroxyl group, carboxyl group, epoxy group, ether, thioether, ester group, amide group, and aryl group. Preferably, R 3 It is a straight-chain alkane, containing 1 to 5 carbon atoms.

[0048] R 4 R is an aliphatic or aromatic group with 1 to 20 carbon atoms. 4 It may contain any one or more of the following as substituents: alcohol hydroxyl group, carboxyl group, epoxy group, ether, thioether, ester group, and amide group. Preferably, R 4 It is a straight-chain alkane, containing 1 to 6 carbon atoms.

[0049] Based on the above embodiments, the solvent includes one or more of the following: n-butyl acetate, ethyl acetate, γ-butyrolactone, propylene glycol methyl ether acetate, propylene glycol methyl ether, and methyl isobutyl ketone; the mass of the solvent is 85% to 98% of the mass of the calixarene derivative photoresist.

[0050] The two types of molecules with the structures of Formula I and Formula II described above can dissolve in specific solvents to form a high-refractive-index near-ultraviolet to deep-ultraviolet photoresist. Organic solvents allow the photoresist to remain in a liquid state, facilitating coating. The aforementioned molecules, when mixed with organic solvents, form a photoresist composition. These organic solvents exhibit good solubility for the main components of the photoresist disclosed herein. Solvent mass ratios within the aforementioned range are advantageous for forming ultrathin films with a thickness of 50 nm or less; excessively low solvent ratios will make it difficult to form ultrathin films via spin coating.

[0051] This disclosure also provides a method for preparing a high-refractive-index calixarene derivative photoresist, please refer to [link to relevant documentation]. Figure 1 The process includes: S11, adding concentrated hydrochloric acid to a resorcinol solution under ice bath conditions, then adding sulfur-containing alkyl aldehydes or aryl aldehydes dropwise, gradually increasing the temperature to allow the sulfur-containing alkyl aldehydes or aryl aldehydes to react with resorcinol, and then washing and drying to obtain calixarene derivative molecules containing a thioether structure; S12, dissolving the product obtained in S11, adding triethylamine under ice bath conditions, then adding sulfonyl chloride containing a diazonoquinone group dropwise to react, and then purifying to obtain calixarene derivative molecules containing a diazonoquinone group and a thioether structure; S13, dissolving the product obtained in S12 in a solvent to obtain a high-refractive-index calixarene derivative photoresist.

[0052] The first preparation method involves reacting sulfur-containing alkyl aldehydes or aryl aldehydes with resorcinol to synthesize a series of sulfur-containing calixarene derivatives. Then, the hydroxyl groups are selectively protected with photosensitive groups to obtain calixarene derivative molecules containing diazononaphthoquinone groups and thioether structures. Finally, the calixarene derivative molecules are dissolved in a solvent to obtain photoresist.

[0053] This disclosure also provides a method for preparing a high-refractive-index calixarene derivative photoresist, please refer to [link to relevant documentation]. Figure 2 The process includes: S21, adding concentrated hydrochloric acid to a resorcinol solution under ice bath conditions, then adding alkyl aldehydes or aryl aldehydes dropwise, gradually increasing the temperature to allow the alkyl aldehydes or aryl aldehydes to react with resorcinol, and then washing and drying to obtain calixarene derivative molecules; S22, dissolving the product obtained in S21, adding ethanethiol, triethylamine and formaldehyde sequentially, and heating to react to obtain calixarene derivative molecules containing a thioether structure; S23, dissolving the product obtained in S22, adding triethylamine under ice bath conditions, then adding sulfonyl chloride containing a diazonoquinone group dropwise to react, and purifying to obtain calixarene derivative molecules containing a diazonoquinone group and a thioether structure; S24, dissolving the product obtained in S23 in a solvent to obtain a high-refractive-index calixarene derivative photoresist.

[0054] The second preparation method is to first react alkyl aldehydes or aryl aldehydes with resorcinol to obtain calixarenes, then introduce sulfur-containing alkyl, aryl, or other groups onto the benzene ring of the calixarenes, and finally introduce photosensitive groups to obtain calixarene derivative molecules containing diazonoquinone groups and thioether structures. Finally, the calixarene derivative molecules are dissolved in a solvent to obtain photoresist.

[0055] This disclosure also provides an application of the aforementioned high-refractive-index calixarene derivative photoresist in immersion imaging lithography and immersion interference lithography in the near-ultraviolet to deep ultraviolet bands.

[0056] The photoresist disclosed herein, composed of calixarane derivative molecules containing diazonoquinone groups and thioether structures, is suitable for immersion lithography. Combined with a light source with wavelengths above 193 nm and a high-n-value immersion solution, high-resolution lithography can be achieved. The immersion solutions suitable for the photoresist disclosed herein include, but are not limited to, perfluorinated carbon, chlorofluorocarbons, siloxanes, aliphatic / alicyclic hydrocarbons, hydrogenated terphenyl, bromonaphthalene, and iodonaphthalene.

[0057] The present disclosure will be further described below through specific embodiments. The following embodiments specifically illustrate the above-mentioned high-refractive-index calixarene derivative photoresist and its preparation method. However, the following embodiments are merely illustrative of the present disclosure, and the scope of the disclosure is not limited thereto.

[0058] The structural formula of the first main component in this embodiment is shown in Formula I:

[0059]

[0060] Among them, R 1 Methyl; R 2 It is a DNQ group, R 2 The grafting rate was 50%; n = 2. The preparation process of this main component is as follows: Figure 3 As shown.

[0061] Specifically, resorcinol 1 (5.506 g) was dissolved in 20 mL of a 1:1 mixture of ethanol and water, and then cooled in an ice bath. Concentrated hydrochloric acid (5 mL) was then slowly added to the system, followed by 3-methylthiopropionaldehyde 2 (5.208 g) added dropwise using a constant-pressure dropping funnel. The system was heated to room temperature and then refluxed at 75 °C for 1 hour. After the reaction was complete, the system was cooled to room temperature, and a small amount of methanol was added, followed by a large amount of pure water. The solid was then filtered out, washed with a large amount of water, dried under vacuum for 12 hours, and purified by column chromatography to obtain the first sulfur-containing calixarene 3.

[0062] The purified first sulfur-containing calixarene 3 (1.9 g) was dissolved in 30 mL of a mixed solvent of N,N-dimethylformamide and acetone (DMF / Actone = 2 / 1). The reaction system was then placed in an ice bath. Triethylamine Et3N (1.721 mL) was slowly added to the reaction system. Then, over half an hour, 1,2-naphthoquinone-2-azido-4-sulfonyl chloride (3.168 g) was dissolved in 15 mL of the above mixed solvent, specifically added dropwise using a constant-pressure dropping funnel. The ice bath was then removed, and the temperature was raised to 25°C for 24 hours. After the reaction was complete, the reaction mixture was added to a large amount of water to precipitate the solid. The solid was filtered off, washed with water at least three times, dried under vacuum for 24 hours, and finally purified by column chromatography to obtain the final product, the first main component 4.

[0063] The structural formula of the second main component in this embodiment is shown in II:

[0064]

[0065] Among them, R 2 It is a DNQ group, R 2 The grafting rate was 50%; R 3 =Ethyl; R 4 It is methyl; n=1. The preparation process of this main component is as follows: Figure 4 As shown.

[0066] Specifically, resorcinol 1 (100 mmol) was dissolved in 50 mL of methanol, and then concentrated HCl (17 mL) was added. The system was then cooled to 0 °C. Triacetaldehyde 5 (35 mmol) was slowly added dropwise to the reaction system using a constant pressure dropping funnel. After the addition was complete, the reaction system was raised to room temperature and then refluxed for 3 hours. After the reaction was complete, the system was cooled to room temperature, and then 3 times the amount of water was added to precipitate the solid. The solid was filtered out, dried, and purified by column chromatography to obtain calixarene 6.

[0067] The obtained calixarene 6 (2.176 g) was dissolved in 80 mL of a mixed solvent of ethanol and chloroform (ethanol / chloroform = 1 / 1). Then, 1.48 mL of ethanethiol was added to the reaction system, followed by 2.78 mL of triethylamine, and then 3.892 g of formaldehyde. The reaction was then refluxed at 60 °C for 24 hours. After the reaction was completed, the solvent was evaporated, and the mixture was purified by column chromatography to obtain the second sulfur-containing calixarene 7.

[0068] 1 mmol of the second sulfur-containing calixarene 7 obtained in the previous step was dissolved in 30 mL of a mixed solvent of acetone and N,N-dimethylformamide (Actone / DMF = 1 / 1). The reaction system was then cooled to 0 °C, and 0.584 mL of triethylamine was slowly added to the reaction system. Then, 1.0747 g of 1,2-naphthoquinone-2-azido-4-sulfonyl chloride was dissolved in 15 mL of the above mixed solvent and slowly added dropwise to the reaction system using a constant pressure dropping funnel. The system was then heated to room temperature and reacted for 24 hours. After the reaction was complete, the system was added to a large amount of water, precipitating a solid. The solid was filtered, washed with a large amount of water, and then dried under vacuum for 24 hours. Column chromatography yielded the final product, the second main component 8.

[0069] The first main component 4 and the second main component 8 were dissolved in solvents to obtain two different high-refractive-index calixarene derivative photoresists. Based on these two high-refractive-index calixarene derivative photoresists, specific examples and comparative examples regarding film preparation and performance testing are provided below.

[0070] Example 1:

[0071] 200 mg of the first main component was dissolved in 5 mL of propylene glycol methyl ether acetate, thoroughly shaken to dissolve, and then filtered to obtain a photoresist solution. 0.1 mL of the photoresist solution was dropped onto a 1-inch sapphire substrate (0.5 mm thick, double-sided polished) that had been ultrasonically treated with acetone and alcohol, and spin-coated into a film. The film was then baked on a 100°C hot plate for 5 minutes, removed, and cooled to room temperature. By adjusting the solid content and spin-coating speed, a film with a thickness of approximately 50 nm was finally obtained. The refractive index of the sample was measured using an ellipsometer (Cauchy model, detection wavelength range 300–700 nm). The results showed that the refractive index of the photoresist film was 1.7004 (see Table 1).

[0072] A matching solution (Cargill Corporation, USA) with a refractive index of 1.474 was uniformly coated onto the above photoresist film. Its main components are aliphatic / alicyclic hydrocarbons and hydrogenated terphenyl. The coated substrate sample was then placed on an immersion prism interference lithography machine for immersion interference exposure at a wavelength of 365 nm. Specifically, the device disclosed in Chinese Patent CN115309009A can be used for this exposure. The resulting interference fringe half-period is 60 nm, and the exposure dose is approximately 40 mJ / cm². 2 After exposure, the photoresist was placed on a hot plate at 100°C and baked for 2 minutes, during which the matching solution on the photoresist surface would completely evaporate. After natural cooling, the sample was immersed in 2.83% tetramethylammonium hydroxide standard developer for 60 seconds, rinsed with ultrapure water, and then dried with nitrogen gas to obtain a high-quality grating pattern with a 60nm half-cycle, as shown below. Figure 5 As shown.

[0073] Example 2:

[0074] 200 mg of the second main component was dissolved in 5 mL of propylene glycol methyl ether acetate, thoroughly shaken to dissolve, and then filtered to obtain a photoresist solution. 0.1 mL of the photoresist solution was dropped onto a 1-inch sapphire substrate (0.5 mm thick, double-sided polished) that had been ultrasonically treated with acetone and alcohol, and spin-coated into a film. The film was then baked on a 100°C hot plate for 5 minutes, removed, and cooled to room temperature. By adjusting the solid content and spin-coating speed, a film with a thickness of approximately 50 nm was finally obtained. The refractive index of the sample was measured using an ellipsometer (Cauchy model, detection wavelength range 300–700 nm). The results showed that the refractive index of the photoresist film was 1.7368 (see Table 1).

[0075] A matching liquid (Cargill Corporation, USA) with a refractive index of 1.474 was uniformly coated on the above photoresist film layer, and immersion interference exposure was performed. The exposure conditions and post-processing conditions were the same as in Example 1, and a similar 60nm half-cycle high-quality grating pattern was finally obtained.

[0076] Comparative Example 1:

[0077] 0.1 mL of commercially available partially protected p-hydroxystyrene (PHS) photoresist was dropped onto a 1-inch sapphire substrate (0.5 mm thick, double-sided polished) that had been ultrasonically treated with acetone and alcohol. The substrate was then spin-coated and baked on a 100°C hot plate for 5 minutes, subsequently removed and cooled to room temperature. A film with a thickness of 50 nm was obtained by adjusting the photoresist concentration and rotation speed. The refractive index of the sample was measured using an ellipsometer (Cauchy model, detection wavelength range 300–700 nm). The results showed that the refractive index of the photoresist film was 1.4739 (see Table 1).

[0078] A matching solution with a refractive index of 1.474 (Cargill Corporation, USA) was uniformly coated onto the above photoresist film, and immersion interference exposure was performed under the same conditions as in Example 1. After exposure, the photoresist was placed on a hot plate at 120°C for 2 minutes, during which the matching solution on the surface of the photoresist completely evaporated. After natural cooling, the sample was immersed in a 2.83% tetramethylammonium hydroxide standard developer for 60 seconds, rinsed with ultrapure water, and then dried with nitrogen gas to obtain the grating pattern as shown. Figure 6 As shown, most of the area is corroded by the matching fluid.

[0079] Comparative Example 2:

[0080] 0.1 mL of commercial phenolic resin photoresist was dropped onto a 1-inch sapphire substrate (0.5 mm thick, double-sided polished) that had been ultrasonically treated with acetone and alcohol. The substrate was then spin-coated into a film and baked on a 100°C hot plate for 5 minutes. Afterward, it was removed and cooled to room temperature. A film with a thickness of 50 nm was obtained by adjusting the photoresist concentration and rotation speed. The refractive index of the sample was measured using an ellipsometer (Cauchy model, detection wavelength range 300–700 nm). The results showed that the refractive index of the photoresist film was 1.5700 (see Table 1).

[0081] A matching solution with a refractive index of 1.474 (Cargill Corporation, USA) was uniformly coated onto the above photoresist film layer, and immersion interference exposure was performed. The exposure and post-processing conditions were the same as in Example 1. A 60nm half-cycle grating pattern was finally obtained, but compared to Example 1, the pattern quality was significantly reduced, and the roughness of the line edges was higher (e.g., ...). Figure 7 (As shown).

[0082] Table 1: Materials and Test Results

[0083]

[0084] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A high refractive index calixarene derivative photoresist, characterized by, The high-refractive calixarene derivative photoresist comprises: a solvent, which is a mixture of one or more of n-butyl acetate, ethyl acetate, gamma-butyrolactone, propylene glycol methyl ether acetate, propylene glycol methyl ether and methyl isobutyl ketone; a host component, which is a calixarene derivative molecule containing a diazonium naphthoquinone group and a sulfide structure; the structure of the host component is shown in the following formula II: wherein R 2 is a diazonium naphthoquinone group or a hydroxyl group, R 2 is at least partially a diazonium naphthoquinone group; R 3 is a linear alkane chain; R 4 is an aliphatic or aromatic group having 1 to 20 carbon atoms; and n = 1 to 4.

2. The high refractive index calixarene derivative photoresist according to claim 1, wherein The R 3 comprise any one or more of an alcohol hydroxyl, a carboxyl, an epoxy, an ether, a thioether, an ester group, an amide group, and an aryl group as a substituent; The R 4 comprise any one or more of an alcohol hydroxyl, a carboxyl, an epoxy, an ether, a thioether, an ester group, and an amide group as a substituent.

3. The high refractive index calixarene derivative photoresist according to claim 1, wherein R is a straight-chain alkane containing 1 to 5 carbon atoms 3 R is a straight-chain alkane containing 1 to 5 carbon atoms 4 R is a straight-chain alkane containing 1 to 6 carbon atoms 4. The high refractive index calixarene derivative photoresist of claim 1, wherein the diazonium naphthoquinone group is the grafting rate of the diazonium naphthoquinone group in the host component is 45% to 65%; n = 1 or 2.

5. The high refractive index calixarene derivative photoresist of claim 1, wherein The mass of the solvent is 85% to 98% of the mass of the calixarene derivative photoresist.

6. A method for preparing a high refractive calixarene derivative photoresist according to any one of claims 1, 4-5, characterized by, The method comprises the following steps: S11, under ice bath, concentrated hydrochloric acid is added to a resorcinol solution, and then a sulfur-containing alkyl aldehyde or aryl aldehyde is added dropwise, the sulfur-containing alkyl aldehyde or aryl aldehyde is allowed to react with the resorcinol by gradually increasing the temperature, and then the product is washed and dried to obtain a calixarene derivative molecule containing a sulfide structure; S12, the product obtained in S11 is dissolved, triethylamine is added under ice bath, and then a sulfuryl chloride containing a diazonium naphthoquinone group is added dropwise to react, and then the product is purified to obtain a calixarene derivative molecule containing a diazonium naphthoquinone group and a sulfide structure; S13, the product obtained in S12 is dissolved in a solvent to obtain a high-refractive calixarene derivative photoresist.

7. A method for preparing a high refractive calixarene derivative photoresist according to any one of claims 1 to 5, characterized by, The method comprises the following steps: S21, under ice bath, concentrated hydrochloric acid is added to a resorcinol solution, and then an alkyl aldehyde or aryl aldehyde is added dropwise, the alkyl aldehyde or aryl aldehyde is allowed to react with the resorcinol by gradually increasing the temperature, and then the product is washed and dried to obtain a calixarene derivative molecule; S22, the product obtained in S21 is dissolved, ethanethiol, triethylamine and formaldehyde are sequentially added, and then the product is obtained after heating reaction, which is a calixarene derivative molecule containing a sulfide structure; S23, the product obtained in S22 is dissolved, triethylamine is added under ice bath, and then a sulfuryl chloride containing a diazonium naphthoquinone group is added dropwise to react, and then the product is purified to obtain a calixarene derivative molecule containing a diazonium naphthoquinone group and a sulfide structure; S24, the product obtained in S23 is dissolved in a solvent to obtain a high-refractive calixarene derivative photoresist.

8. Application of the high-refractive calixarene derivative photoresist according to any one of claims 1 to 5 in near-ultraviolet to deep-ultraviolet waveband immersion imaging lithography and immersion interference lithography.

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