Method for preparing nano-porous pattern by using hybrid photoresist

Abstract

The invention provides a method for preparing a nano-porous pattern by using a hybrid photoresist. The method comprises the following steps: preparing a photoresist solution containing the hybrid photoresist; standing and aging the photoresist solution in a controllable environment for a preset period of time to induce formation of metal cluster molecules in the photoresist solution so as to obtain an aged photoresist solution; the aged photoresist solution is filtered, metal cluster molecules with target size distribution are screened out, and a filtered photoresist solution is obtained; forming a photoresist layer on the substrate by using the filtered photoresist solution; the photoresist layer is exposed, so that the substrate around the metal cluster molecules in the photoresist layer is subjected to a photochemical reaction; and developing the exposed photoresist layer, and forming a nano-porous pattern in the photoresist layer.

Description

Technical Field

[0001] This disclosure relates to the fields of photonic crystals, porous electrode sensors, and integrated circuit thin film technology, and more specifically to a method for preparing nanoporous patterns using hybrid photoresist. Background Technology

[0002] Nanoporous patterns exist as micro / nano structures in fields such as photonic crystals, porous electrode sensors, and integrated circuit thin films. Currently, the fabrication of nanoporous patterns is mainly achieved through techniques such as photolithography and etching, phase separation, sol-gel, and block copolymer self-assembly.

[0003] Photolithography combined with etching is a complex process for fabricating nanoporous patterns, highly susceptible to the influence of light source wavelength, making it difficult to economically achieve the fabrication of nanoscale porous patterns. Phase separation methods are easily affected by process conditions such as solvent evaporation rate, heating temperature, and humidity, making it difficult to guarantee the uniformity of the size and shape of the porous patterns. Sol-gel methods require high rigidity and stability of the photolithography material. Block copolymer self-assembly technology requires high thermal stability of the material and stringent annealing processes. Summary of the Invention

[0004] In view of this, the present disclosure provides a method for preparing nanoporous patterns using hybrid photoresist, which can at least partially solve the above-mentioned technical problems.

[0005] This disclosure provides a method for preparing nanoporous patterns using hybrid photoresist, comprising: preparing a photoresist solution containing hybrid photoresist; aging the photoresist solution under controlled conditions for a preset time period to induce the formation of metal cluster molecules in the photoresist solution, thereby obtaining an aged photoresist solution; filtering the aged photoresist solution to screen out metal cluster molecules with a target size distribution, thereby obtaining a filtered photoresist solution; forming a photoresist layer on a substrate using the filtered photoresist solution; exposing the photoresist layer to induce a photochemical reaction in the matrix surrounding the metal cluster molecules in the photoresist layer; and developing the exposed photoresist layer to form nanoporous patterns in the photoresist layer.

[0006] According to embodiments of this disclosure, the hybrid photoresist has the following structural formula: (R1) n M(XR2R3) 4-n Where n is 1 or 2, M is a metal or metalloid precursor, R1 is a C1-C10 alkyl group or an isomer of a C1-C10 alkyl group, R2 and R3 are C1-C6 alkyl groups or isomers of a C1-C6 alkyl group, and X is one of N and O.

[0007] According to embodiments of this disclosure, M is one of tin, tellurium, and silicon; R1 is one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, phenyl, and benzyl; R2 and R3 are one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and phenyl.

[0008] According to embodiments of this disclosure, preparing a photoresist solution containing a hybrid photoresist includes: dissolving at least one hybrid photoresist in an organic solvent to prepare a photoresist solution with a mass fraction of 1wt% to 20wt%; wherein the organic solvent is at least one selected from propylene glycol methyl ether, propylene glycol methyl ether acetate, butyl acetate, ethyl lactate, methyl isobutyl ketone, n-hexanol, isopropanol, and anisole.

[0009] According to embodiments of this disclosure, the photoresist solution is aged under a controlled environment for a preset time period, including: aging the photoresist solution under a controlled environment with a temperature of 15°C to 40°C and a relative humidity of 30% to 80% for 1 hour to 200 hours; wherein the size of the metal cluster molecules is positively correlated with the aging time.

[0010] According to embodiments of this disclosure, filtering an aged photoresist solution includes: filtering the aged photoresist solution using a filter membrane with a preset pore size, wherein the preset pore size ranges from 0.1 μm to 5.0 μm.

[0011] According to embodiments of this disclosure, forming a photoresist layer on a substrate using a filtered photoresist solution includes: spin-coating the filtered photoresist solution onto the substrate at a rotation speed of 500 rpm to 4000 rpm to form a photoresist film layer; and baking the photoresist film layer at a temperature of 60°C to 100°C for 1 min to 10 min to remove residual solvent and form a photoresist layer.

[0012] According to embodiments of this disclosure, exposing a photoresist layer includes exposing the photoresist layer with ultraviolet light of wavelength from 193 nm to 450 nm.

[0013] According to embodiments of this disclosure, developing an exposed photoresist layer to form a nanoporous pattern in the photoresist layer includes: negatively developing the exposed photoresist layer with a developer to remove metal cluster molecules in the photoresist layer and form a nanoporous pattern in the photoresist layer.

[0014] According to embodiments of this disclosure, the developer includes at least one selected from propylene glycol methyl ether, propylene glycol methyl ether acetate, butyl acetate, ethyl lactate, methyl isobutyl ketone, n-hexanol, isopropanol, cyclohexanone, n-hexane, butyl acetate, amyl acetate, hexyl acetate, and anisole.

[0015] The method for preparing nanoporous patterns using hybrid photoresist provided in this disclosure has at least the following technical effects.

[0016] This method actively guides the self-assembly and formation of metal cluster molecules in a photoresist solution by allowing it to age under controlled conditions. Subsequently, fine filtration technology is used to screen out cluster molecules with the target pore size. Based on the treated solution, standard processes such as spin coating, pre-baking, exposure, and development are then applied to obtain well-structured, high-density, and uniformly sized nanoporous patterns.

[0017] This method can control the size and uniformity of metal nanoclusters by using two variables: aging time of the hybrid photoresist solution and filter membrane pore size. It does not require complex and expensive equipment, which greatly reduces the manufacturing cost.

[0018] This method is highly compatible with standard photolithography processes and can be easily scaled up on existing semiconductor production lines to achieve large-area, large-scale fabrication. It can improve the fabrication efficiency of nanoporous patterns and solve the problem of low efficiency in traditional methods. Attached Figure Description

[0019] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments of this disclosure with reference to the accompanying drawings.

[0020] Figure 1 A flowchart illustrating a method for fabricating nanoporous patterns using hybrid photoresist according to an embodiment of the present disclosure is shown.

[0021] Figure 2 The illustration shows a schematic diagram of the operation of a method for preparing nanoporous patterns using hybrid photoresist according to an embodiment of the present disclosure.

[0022] Figure 3 The diagram illustrates a SEM image of a nanoporous pattern formed according to Embodiment 1 of the present disclosure.

[0023] Figure 4 An SEM image of a nanoporous pattern formed according to Embodiment 6 of this disclosure is shown schematically.

[0024] Figure 5 An SEM image of a nanoporous pattern formed according to Embodiment 10 of this disclosure is shown schematically. Detailed Implementation

[0025] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0026] To address the shortcomings of existing technologies, embodiments of this disclosure provide a method for fabricating nanoporous patterns using hybrid photoresists. This method leverages the synergistic control of hybrid photoresist solution aging, filtration, exposure, and development to regulate the size and uniformity of the nanopore array, achieving a balance between cost, efficiency, precision, and good process compatibility. A detailed description is provided below with reference to the accompanying drawings and specific embodiments.

[0027] Figure 1 A flowchart illustrating a method for fabricating nanoporous patterns using hybrid photoresist according to an embodiment of the present disclosure is shown. Figure 2 The illustration shows a schematic diagram of the operation of a method for preparing nanoporous patterns using hybrid photoresist according to an embodiment of the present disclosure.

[0028] like Figure 1 and Figure 2 As shown, the method for preparing nanoporous patterns using hybrid photoresist in this embodiment may include operations S110 to S160.

[0029] In operation S110, a photoresist solution containing hybrid photoresist is prepared.

[0030] In operation S120, the photoresist solution is left to stand and age for a preset time under a controlled environment to induce the formation of metal cluster molecules in the photoresist solution, thereby obtaining the aged photoresist solution.

[0031] In operation S130, the aged photoresist solution is filtered to screen out metal cluster molecules with the target size distribution, and the filtered photoresist solution is obtained.

[0032] In operation S140, a photoresist layer is formed on the substrate using the filtered photoresist solution.

[0033] During operation S150, the photoresist layer is exposed, causing a photochemical reaction to occur in the matrix surrounding the metal cluster molecules in the photoresist layer.

[0034] In operation S160, the exposed photoresist layer is developed to form a nanoporous pattern in the photoresist layer.

[0035] According to embodiments of this disclosure, hybrid photoresist can be a composite material formed by combining inorganic nanoparticles (such as metal oxides and metal nanoclusters) with organic polymers, thus possessing the properties of both. Hybrid photoresist can utilize the light absorption and etching resistance properties of inorganic components to enhance the resolution, sensitivity, and contrast of the photoresist, while retaining the film-forming properties and design flexibility of organic components.

[0036] According to embodiments of this disclosure, metal precursors can undergo directional assembly with ligands under a controlled environment. The controlled environment provides sufficient energy for the metal ions and ligands to overcome steric hindrance and form metal clusters with specific structures. In the photoresist, the acetal-protected polymer undergoes hydrolysis during aging. Under acid catalysis, the acetal bonds break rapidly, restoring the phenolic hydroxyl groups and releasing metal ions. These metal ions bind to ligands in solution, further promoting the formation of metal clusters.

[0037] In some embodiments, the structure of the hybrid photoresist can be: (R1) n M(XR2R3) 4-n .

[0038] Where n takes the value of 1 or 2, M is a metal or metalloid precursor, R1 is a C1~C10 alkyl group or an isomer of a C1~C10 alkyl group, R2 and R3 are C1~C6 alkyl groups or isomers of a C1~C6 alkyl group, and X is one of N and O.

[0039] Furthermore, the metal or metalloid precursor is preferably one of tin (Sn), tellurium (Te), and silicon (Si), and R1 is preferably one of methyl (Me), ethyl (Et), n-propyl (n-Pr), isopropyl (i-Pr), n-butyl (n-Bu), isobutyl (i-Bu), tert-butyl (t-Bu), n-pentyl (n-Bu), n-hexyl (n-Hex), n-octyl (n-Oct), phenyl (Ph), benzyl (Bn), etc. R2 = R3 (representing the same group), preferably one of methyl (Me), ethyl (Et), n-propyl (n-Pr), isopropyl (i-Pr), n-butyl (n-Bu), isobutyl (i-Bu), tert-butyl (t-Bu), phenyl (Ph), etc.

[0040] In some embodiments, preparing a photoresist solution containing a hybrid photoresist includes: dissolving at least one hybrid photoresist in an organic solvent to prepare a photoresist solution with a mass fraction of 1 wt% to 20 wt%. The organic solvent may be at least one selected from propylene glycol methyl ether (PGME), propylene glycol methyl ether acetate (PGMEA), butyl acetate (BuAc), ethyl lactate, methyl isobutyl ketone (MIBK), n-hexanol, isopropanol (IPA), and anisole. IPA is preferred as the organic solvent.

[0041] For example, the synthesis of tBuSn(N(Me)2)3 is as follows:

[0042]

[0043] Dissolve 0.5g-5g of A in 5mL-50mL of dichloromethane. Place the reaction system in an ice bath. Then, slowly add 0.1g-2.0g of tBuMgBr to the reaction system. Stir for 10-30 minutes in an ice bath, then slowly heat to room temperature and continue stirring for half an hour. Finally, heat to 70°C. o C~100 o Reflux C for 3-10 hours. After the reaction is complete, remove the solvent by vacuum distillation to obtain the target product.

[0044] (R1)nM(XR2R3)4-n(n=1, 2)(R1=Me, Et, i-Pr, t-Bu, Ph, etc., M=Sn, Ge, etc., X=O, N, etc., R2 and R3 are the same The synthesis methods for Me, Et, i-Pr, t-Bu, Ph, etc. complexes are the same as those described above.

[0045] For example, the synthesis of tBuSi(OtBu)3 is as follows:

[0046]

[0047] Dissolve 1-10g of A in 5-50mL of tert-butanol. Place the reaction system in an ice bath under argon protection. Slowly add 0.1-2.5g of tBuMgBr to the reaction system. Stir for 5-30 minutes in an ice bath, then slowly heat to room temperature and continue stirring for half an hour. Finally, heat to 80°C. o C~120 o The reaction is carried out at C for 12-24 hours. After the reaction is completed, the solvent is removed by vacuum distillation. The reaction mixture is added to a large amount of water to precipitate the solid. The solid is filtered out and washed with water at least 3 times. The solid is then dried under vacuum for 24-48 hours to obtain the target product.

[0048] (R1)nM(XR2R3)4-n(n=1, 2)(R1=Me, Et, i-Pr, t-Bu, Ph, etc., M =Si, X =O, N, etc., R2 and R3 are the same. The synthesis methods for Me, Et, i-Pr, t-Bu, Ph, etc. complexes are the same as those described above.

[0049] In some embodiments, aging the photoresist solution under controlled conditions for a preset period of time may include: aging the photoresist solution under controlled conditions at a temperature of 15°C to 40°C and a relative humidity of 30% to 80% for 1 hour to 200 hours. Preferably, the temperature is 25°C.

[0050] According to embodiments of this disclosure, the aging temperature must be strictly controlled within a specific range to prevent side reactions. High temperatures may accelerate the aggregation of metal clusters, while low temperatures may lead to excessively slow reaction rates. By precisely controlling the temperature, slow and orderly growth of metal clusters can be achieved. The duration of aging directly affects the size and distribution of metal clusters. Within a preset time period, the metal precursor and ligand have sufficient time for directional assembly and chemical reactions to form metal clusters with uniform size and narrow distribution. That is, the size of the metal cluster molecules is positively correlated with the aging time. Short aging times (t=1h~50h) can form smaller and more uniform cluster particles. Longer aging times (t=150h~200h) can form larger and more uniform cluster particles.

[0051] In some embodiments, filtering the aged photoresist solution may include filtering the aged photoresist solution using a filter membrane with a preset pore size, wherein the preset pore size ranges from 0.1 μm to 5.0 μm.

[0052] According to embodiments of this disclosure, the aging time t and the filter membrane pore size D jointly determine the particle size and uniformity of the nanocluster molecules. Short aging times (t=1h~50h) result in smaller and more uniform cluster particles; when combined with a filter membrane with smaller pore sizes, nanoporous patterns with pore sizes of 80nm~160nm and uniform shapes can be obtained. Longer aging times (t=150h~200h) result in larger and more uniform cluster particles; when combined with a filter membrane with larger pore sizes, nanoporous patterns with pore sizes of 700nm~800nm ​​and more uniform shapes can be obtained.

[0053] In some embodiments, forming a photoresist layer on a substrate using a filtered photoresist solution may include: spin-coating the filtered solution onto the substrate at a rotation speed of 500 rpm to 4000 rpm to form a photoresist film layer; and baking the photoresist film layer at a temperature of 60°C to 100°C for 1 min to 10 min to remove residual solvent, thereby forming the photoresist layer.

[0054] The substrate can be an insulating substrate or a semiconductor substrate, preferably a silicon wafer, sapphire, quartz or silicon carbide.

[0055] In some embodiments, exposing the photoresist layer may include exposing the photoresist layer with ultraviolet light with a wavelength of 193nm to 450nm.

[0056] During the aging process, the photosensitivity of the clusters formed is greatly reduced or even partially lost. Exposure can allow photochemical reactions to continue between the metal cluster molecules. In some embodiments, developing the exposed photoresist layer to form a nanoporous pattern in the photoresist layer may include: negatively developing the photoresist layer after exposure using a developer to remove the metal cluster molecules in the photoresist layer and form a nanoporous pattern in the photoresist layer.

[0057] Because the metal cluster molecules have significant polarity differences as negative photoresists during the development process, nanoporous patterns are formed in the negative photoresist film layer.

[0058] Furthermore, the developer includes at least one of propylene glycol methyl ether, propylene glycol methyl ether acetate, butyl acetate, ethyl lactate, methyl isobutyl ketone, n-hexanol, isopropanol, cyclohexanone, n-hexane, butyl acetate, amyl acetate, hexyl acetate, and anisole.

[0059] Furthermore, the exposed nanoporous pattern is subjected to reactive ion etching (RIE). Etching gases such as SF6:Ar are used for etching transfer of the nanoporous pattern, with an etching gas ratio of 1:1 to 8:1, an etching time of 20 to 200 seconds, and an etching depth of 50 nm to 300 nm. After the etching process is complete, the substrate is removed and cleaned with at least one organic solvent selected from isopropanol, cyclohexanone, n-hexane, butyl acetate, amyl acetate, hexyl acetate, anisole, and acetone to obtain a clean nanoporous pattern.

[0060] To more clearly illustrate the method for fabricating nanoporous patterns using hybrid photoresist provided in this disclosure, some specific embodiments and comparative examples are provided below, using a self-assembled grating pattern as an example.

[0061] Weigh 100 mg of the synthesized hybrid photoresist and dissolve it in isopropanol (2 mL). After sonication for 20 min, the photoresist solution is aged at 25°C in the dark for 48 h. The aged solution is then filtered through a 0.22 μm filter membrane. Finally, the filtered solution is spin-coated onto a silicon wafer treated with a piranha solution (70% concentrated sulfuric acid + 30% hydrogen peroxide) at 3000 rpm and pre-baked at 100°C for 120 s. The wafer is then exposed to ultraviolet light (wavelength 193 nm ~ 400 nm) at a dose of 100 mJ / cm². -2 ~500mJ / cm -2Use any one of propylene glycol methyl ether (PGME), propylene glycol methyl ether acetate (PGMEA), butyl acetate (BuAc), ethyl lactate, methyl isobutyl ketone (MIBK), n-hexanol, isopropanol (IPA), or anisole. Develop for 30 seconds, rinse with isopropanol, dry with nitrogen, and observe with a scanning electron microscope (SEM).

[0062] Table 1. Effects of different developing solutions on the formation of nanoporous patterns

[0063]

[0064] Figure 3 The diagram illustrates a SEM image of a nanoporous pattern formed according to Embodiment 1 of the present disclosure. Figure 4 An SEM image of a nanoporous pattern formed according to Embodiment 6 of this disclosure is shown schematically.

[0065] Combined with Table 1, Figure 3 and Figure 4 It can be seen that the method for preparing nanoporous patterns using hybrid photoresist provided in the embodiments of this disclosure can obtain nanoporous patterns with good uniformity. Furthermore, a comparison of Examples 1-7 of this disclosure with Comparative Examples 1 and 2 shows that different developing solutions can affect the formation of nanoporous patterns.

[0066] Weigh 100 mg of the above-mentioned synthetic hybrid photoresist and dissolve it in isopropanol (2 mL). After sonication for 20 min, the solution is aged at 25°C in the dark for 24-120 h. The aged solution is then filtered through filter membranes with filter diameters of 0.22 μm, 0.25 μm, and 0.8 μm. Finally, the filtered solution is spin-coated onto a silicon wafer treated with a piranha solution (70% concentrated sulfuric acid + 30% hydrogen peroxide) at 3000 rpm, pre-baked at 100°C for 120 s, and then exposed to ultraviolet light (wavelength 193 nm-400 nm) at an exposure dose of 100 mJ / cm². -2 ~500mJ / cm -2 The sample was developed using PGMEA for 30 seconds, rinsed with isopropanol, dried with nitrogen, and observed using a scanning electron microscope (SEM). It was then exposed to EBL to determine its photosensitive dose.

[0067] Table 2. Effects of different aging times t and membrane pore size D on the formation of nanoporous patterns.

[0068]

[0069] Figure 5 An SEM image of a nanoporous pattern formed according to Embodiment 10 of this disclosure is shown schematically.

[0070] Combined with Table 1, Figure 5It can be seen that the method for preparing nanoporous patterns using hybrid photoresist provided in this disclosure can obtain nanoporous patterns with good uniformity. Furthermore, comparing Example 8 with Comparative Example 3, it can be seen that the aging time t and the filter membrane pore size D jointly determine the diameter of the nanopores and the uniformity of the porous pattern. Referring to Comparative Examples 4 and 5, it can be seen that metal elements such as potassium (K) and sodium (Na) have no effect on the formation of nanoporous patterns, while metal elements such as Sn, Si, and Ge have a significant impact on the formation of porous patterns. That is, hybrid photoresists constructed with metal elements other than Sn, Si, and Ge are not suitable for the preparation method of this disclosure.

[0071] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A method for preparing nanoporous patterns using hybrid photoresist, characterized in that, include: Prepare a photoresist solution containing hybrid photoresist; The photoresist solution is left to stand and age in a controlled environment for a preset time period to induce the formation of metal cluster molecules in the photoresist solution, thereby obtaining an aged photoresist solution. The aged photoresist solution is filtered to screen out metal cluster molecules with the target size distribution, resulting in a filtered photoresist solution. A photoresist layer is formed on the substrate using the filtered photoresist solution; The photoresist layer is exposed to cause a photochemical reaction in the matrix surrounding the metal cluster molecules in the photoresist layer. The exposed photoresist layer is developed to form a nanoporous pattern in the photoresist layer.

2. The method according to claim 1, characterized in that, The structure of the hybrid photoresist is as follows: (R1) n M(XR2R3) 4-n ; Wherein, n takes the value of 1 or 2, M is a metal or metalloid precursor, R1 is a C1~C10 alkyl group or an isomer of the C1~C10 alkyl group, R2 and R3 are C1~C6 alkyl groups or isomers of the C1~C6 alkyl groups, and X is one of N and O.

3. The method according to claim 2, characterized in that, M is one of tin, tellurium, and silicon; R1 is one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, phenyl, and benzyl; R2 and R3 are one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and phenyl.

4. The method according to any one of claims 1 to 3, characterized in that, The preparation of the photoresist solution containing hybrid photoresist includes: Dissolve at least one of the hybrid photoresists in an organic solvent to prepare a photoresist solution with a mass fraction of 1wt% to 20wt%; wherein the organic solvent is at least one selected from propylene glycol methyl ether, propylene glycol methyl ether acetate, butyl acetate, ethyl lactate, methyl isobutyl ketone, n-hexanol, isopropanol, and anisole.

5. The method according to claim 1, characterized in that, The step of allowing the photoresist solution to stand and age in a controlled environment for a preset time period includes: The photoresist solution was aged for 1 hour to 200 hours in a controlled environment with a temperature of 15°C to 40°C and a relative humidity of 30% to 80%. The size of the metal cluster molecules formed in the photoresist solution is positively correlated with the aging time.

6. The method according to claim 1 or 5, characterized in that, The filtering of the aged photoresist solution includes: The aged photoresist solution is filtered using a filter membrane with a preset pore size, which ranges from 0.1 μm to 5.0 μm.

7. The method according to claim 1, characterized in that, The process of forming a photoresist layer on a substrate using the filtered photoresist solution includes: The filtered photoresist solution is spin-coated onto the substrate at a rotation speed of 500 rpm to 4000 rpm to form a photoresist film layer; The photoresist film is baked at a temperature of 60°C to 100°C for 1 min to 10 min to remove residual solvent and form the photoresist layer.

8. The method according to claim 1, characterized in that, The exposure of the photoresist layer includes: The photoresist layer is exposed using ultraviolet light with a wavelength of 193nm~450nm.

9. The method according to claim 1, characterized in that, The step of developing the exposed photoresist layer to form a nanoporous pattern in the photoresist layer includes: The exposed photoresist layer is negatively developed using a developer to remove the metal cluster molecules in the photoresist layer, thereby forming a nanoporous pattern in the photoresist layer.

10. The method according to claim 9, characterized in that, The developing solution includes at least one of propylene glycol methyl ether, propylene glycol methyl ether acetate, butyl acetate, ethyl lactate, methyl isobutyl ketone, n-hexanol, isopropanol, cyclohexanone, n-hexane, butyl acetate, amyl acetate, hexyl acetate, and anisole.

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