Zinc-oxygen cluster molecule, photoresist, preparation method and application
By preparing zinc oxide clusters with small particle size and narrow distribution as the main material of photoresist, the problems of large size and wide distribution of metal oxide cluster photoresist in the prior art have been solved, realizing the preparation and application of high-resolution photoresist.
Patent Information
- Application Number
- CN202511617962.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-06
- Publication Date
- 2026-02-10
AI Technical Summary
Among existing high-resolution photoresist materials, metal oxide cluster photoresists have a large average size and wide size distribution, which makes it difficult to improve their etching resistance. In addition, zinc oxide clusters have large particle size, wide particle size distribution, and unsatisfactory purity, which limits further improvement of photoresist performance.
By reacting a monodentate ligand with a zinc source and controlling the temperature and settling time, zinc oxide clusters with small particle size and narrow particle size distribution were prepared. These clusters were then used as the main material of a photoresist and combined with photoreactive groups to form a photoresist composition with radiation-induced solubility transition.
The preparation of high-resolution photoresist has been achieved, which has good thermal stability and solubility, and can form high-precision photolithographic patterns through extreme ultraviolet lithography or electron beam lithography systems.
Smart Images
Figure CN121494874A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of photolithography technology, specifically relating to a zinc oxide cluster-based photoresist, its preparation method, and its application. Background Technology
[0002] The fabrication of high-resolution patterns on integrated circuits requires photoresist substrate materials with high etching resistance and small molecular size. However, purely organic substrate materials (such as polymers and molecular glasses) are considered insufficient to provide adequate etching resistance in high-resolution lithography. Since metal elements can enhance the etching resistance of materials, the development of metal-oxide-semiconductor (MOC) photoresists with high metal content has become one of the research hotspots in the field of high-resolution lithography. However, the application of MOCs still faces the problems of large average size and wide size distribution, which makes it difficult to further improve the performance of photoresists.
[0003] Metal-organic frameworks (MOFs) are constructed by bridging metal-containing structural units (MBUs) (e.g., metal ions or clusters) with organic ligands. The small size (1–2 nm) of these MBUs, coupled with their ability to provide metal elements with high etching resistance, makes them promising candidates for high-resolution photolithography. However, MBU units in MOFs are typically coordinated with multidentate ligands, forming insoluble coordination polymers that are difficult to undergo a radiation-induced solubility transition, limiting their application in photoresists. Zinc possesses a higher extreme ultraviolet (EUV) absorption cross-section than elements such as C, H, and O, and exhibits lower toxicity, making it a potential candidate for constructing high-resolution photoresist host materials. However, the large particle size, wide particle size distribution, and less-than-ideal purity of zinc oxide clusters limit further improvements in photoresist performance. Summary of the Invention
[0004] The first technical problem to be solved by this invention is to provide a zinc oxide cluster. This zinc oxide cluster has sufficient thermal stability to meet the requirements of photolithography processes; in addition, it has good solubility in some common solvents and can be spin-coated onto the surface of a silicon wafer to form a uniform and flat thin film.
[0005] The second technical problem to be solved by this invention is to provide a method for preparing the above-mentioned zinc oxide clusters. This method uses one or more of alkyl zinc chloride, alkyl zinc oxide, hydroxyalkyl zinc chloride, and alkyl zinc acid as zinc sources to directly react with carboxylic acid ligands, preparing a series of alkyl zinc-based derivatives in one step. The synthesis process is simple, and the products can be separated from the system by filtration or rotary evaporation under reduced pressure.
[0006] The third technical problem to be solved by the present invention is to provide the application of photoresist based on the above-mentioned zinc oxide cluster as the main material in electron beam lithography.
[0007] The technical solution adopted in this invention is as follows: I. A zinc-oxygen cluster: The general molecular formula of the zinc-oxygen cluster is Zn. a O b [A] c [B] d Where a takes values from 1 to 4, 1.5a≤b≤6a, c takes values from 1 to 4, d takes values from 1 to 4, A is the first organic ligand, B is the second organic ligand, and both the first organic ligand A and the second organic ligand B are organic groups; Furthermore, in the molecular structure of the zinc-oxygen cluster, 1 to 4 Zn atoms are connected to the first organic ligand A through surrounding O atoms, and the second organic ligand B is located at the Zn... a O b The two ends of the kernel are connected to individual Zn atoms.
[0008] The first organic ligand A and the second organic ligand B together constitute the coordination moiety of the zinc-oxygen cluster. The first organic ligand A is selected from one or more substituted or unsubstituted aliphatic groups, and the second organic ligand B is selected from one or more substituted or unsubstituted aromatic groups.
[0009] The aliphatic group is a C1C10 chain hydrocarbon group or a C3C10 cyclic hydrocarbon group. Preferably, the chain hydrocarbon group is a straight-chain or branched alkyl, alkenyl or alkynyl group. The aromatic group has one or more aromatic rings, substituted aromatic rings, heteroaromatic rings, or substituted heteroaromatic rings, preferably substituted phenyl.
[0010] The first organic ligand A and the second organic ligand B include: The first organic ligand A is a carboxylic acid ligand with ≤12 carbon atoms, and its structure is as follows: Where C n =C 0~12 Saturated or unsaturated hydrocarbon groups; The second organic ligand B is, or various aromatic acids, with the following structure: R1 to R5 are hydrogen atoms, halogen atoms, hydroxyl groups, methoxy groups, or vinyl groups; the substituents R1 to R5 may be the same or different.
[0011] In the actual reaction, some water molecules will participate in the coordination reaction, but not all of them are water molecules.
[0012] The zinc-oxygen cluster has photoreactive groups, wherein at least one of the first organic ligand A and the second organic ligand B has photoreactive groups, resulting in both having photoreactive groups; the photoreactive groups are selected from one or more of carbon-carbon double bonds, acyloxy groups, acyl groups, aldehyde groups, ester groups, carboxyl groups, and amino groups.
[0013] When a = 3, the two Zn atoms are located in the Zn a O b The two ends of the core are opposite each other and are respectively connected to the N atoms in the two second organic ligands B; When a = 2, the two Zn atoms are connected to the first organic ligand A through the surrounding O atoms, and the N atoms in the two second organic ligands B are located in the Zn a O b The two ends of the core are connected to the two Zn atoms, respectively.
[0014] The general molecular formula of the zinc-oxygen cluster is Zn2O8[A]4[B]2, Zn3O 12 [A]6 [B]2 or Zn3O 10 [A]6[B]2; The zinc-based metal-organic nanoparticles, i.e. zinc-oxygen clusters, have a size of 1 nm to 4 nm.
[0015] II. A method for preparing zinc-oxygen clusters: (1) Under the protection of an inert gas, a zinc salt solution is provided or prepared, the zinc salt solution comprising a first solvent and a zinc source dispersed in the first solvent; a ligand is added to the zinc salt solution and mixed evenly to prepare a zinc-containing reaction system; (2) Heating the zinc-containing reaction system, and during the heating process, the zinc-containing reaction system is reacted at a temperature of 20℃~120℃ for 12h~48h to generate zinc-oxygen clusters; (3) Stop heating, let stand until solid components precipitate, obtain the solid components by filtration and dry the solid components to obtain the zinc oxide cluster.
[0016] In some traditional methods for preparing zinc oxide clusters, zinc salts and ligands are usually added to a solution and mixed evenly. Then, zinc oxide nanoparticles are prepared by hydrolysis with water. However, the zinc oxide prepared by this mixing method usually has a complex crystal form and does not have a fixed crystal structure. The final powder is usually white.
[0017] In the method for preparing zinc-oxygen clusters provided in the above embodiments, a zinc salt solution is prepared in advance, and then the ligand is added to the zinc salt solution and mixed thoroughly. The thermodynamic process of the reaction of the zinc salt solution is controlled by controlling the temperature, so as to form zinc-oxygen clusters with uniform size and the same molecular structure, which can be precipitated in the form of crystals.
[0018] The zinc source is selected from one or more of alkyl zinc chloride, alkyl zinc oxide, hydroxyalkyl zinc chloride, and zinc salts; In one specific example, the zinc salt is selected from salts containing zinc ions, and is one or more of zinc carboxylate, zinc sulfonate, zinc alkoxide, zinc halide, zinc nitrate, and zinc sulfate; in particular, the zinc salt may be zinc alkoxide.
[0019] The zinc salt solution contains 40% to 80% zinc salt by mass. The first solvent is selected from one or more of alcohol solvents, ester solvents, hydrocarbon solvents, and benzene solvents; The ligand is selected from carboxylic acid ligands; optionally, the ligand is selected from one or more of methacrylic acid, acrylic acid, p-vinylbenzoic acid, p-trifluoromethylbenzoic acid, m-methylbenzoic acid, 2-(trifluoromethyl)acrylic acid, benzoic acid and 3,3-dimethacrylic acid.
[0020] The ligands coat the zinc atoms after the reaction. Simultaneously, the ligands have a stabilizing effect on the formation of zinc oxide grains. In the zinc-containing reaction system, the molar ratio of zinc atoms in the zinc source to the ligands is 1:(0.1–10).
[0021] In one specific example, the process includes a step of dispersing the zinc salt in a first solvent to prepare a zinc salt solution before adding the ligand to the zinc salt solution. After the zinc salt is uniformly dispersed in the first solvent, the ligand is then added to the zinc salt solution to prepare a zinc-containing reaction system.
[0022] In one specific example, after adding the ligand to the zinc salt solution, stirring is used to ensure uniform mixing between the ligand and the zinc salt solution. The stirring method can be rod stirring, mechanical stirring, or magnetic stirring. Optionally, magnetic stirring is used. The stirring time is sufficient to ensure uniform mixing between the zinc salt solution and the ligand; the stirring time should not be too long. In one specific example, the stirring time is 1 min to 10 min; optionally, the stirring time is 5 min.
[0023] Furthermore, by controlling the specific temperature conditions of the reaction process, the thermodynamic process of the reaction can be further optimized to obtain zinc oxide with more uniform nanoparticle size and single-crystal form. During the heating of the zinc-containing reaction system, the system is reacted at a temperature of 20℃ to 120℃ for 12h to 48h to generate zinc-oxygen clusters. Correspondingly, a zinc-oxygen cluster is prepared by the method for preparing zinc-oxygen clusters according to any of the above embodiments, wherein the zinc-oxygen cluster is a crystal with a particle size between 1 nm and 4 nm.
[0024] After heating of the zinc-containing reaction system is stopped, it needs to be allowed to stand for 24 to 72 hours to allow the reaction system to gradually reach its lowest energy state. At this time, zinc element precipitates in the form of zinc oxide crystals, which have the advantages of uniform particle size distribution and small particle size. Optionally, during the standing process, the temperature of the zinc-containing reaction system is controlled between 15°C and 35°C. Further, the zinc-containing reaction system can be kept at room temperature.
[0025] After allowing the mixture to stand until a solid component precipitates, the process further includes filtering to obtain the solid component and drying it. Optionally, the solid component can be dried under vacuum. The vacuum drying temperature can be ambient temperature, for example, 15°C to 35°C.
[0026] The experiment of this invention found that by reasonably controlling the order of addition of each raw material and the temperature conditions of the reaction process, the reaction system containing zinc salt can spontaneously form crystalline zinc-oxygen clusters during the standing process. This may be due to the fact that the zinc-oxygen clusters formed under the optimized conditions of this method have uniform size and the same molecular structure, so that zinc-oxygen cluster materials can be obtained in bulk form.
[0027] Specifically, the zinc oxide cluster includes zinc oxide particles and ligands coating the zinc oxide particles, wherein the zinc oxide particles are crystalline and the particle size is between 1 nm and 3 nm.
[0028] III. Application of the zinc oxide cluster in photoresist.
[0029] IV. A photoresist composition, comprising: a second solvent and a photosensitizer and a photolithographic material dispersed in the second solvent, wherein the photolithographic material comprises the zinc oxide cluster. The photolithographic material accounts for 1% to 15% by weight in the photoresist composition, the photosensitizer accounts for 0.005% to 1.5% by weight in the photoresist composition, the organic base accounts for 0% to 0.1% by weight in the photoresist composition, and the remainder is the second solvent.
[0030] Furthermore, the aforementioned photoresist composition is used in the preparation of photolithographic patterns.
[0031] Specifically, extreme ultraviolet lithography or electron beam lithography is used for exposure when preparing photolithographic patterns.
[0032] In one specific example, the photoresist material comprises 1% to 15% by weight in the photoresist composition. Optionally, the photoresist material comprises 5% to 15% by weight. More preferably, the photoresist material comprises 8% to 12% by weight.
[0033] In one specific example, the weight percentage of the photosensitizer in the photoresist composition is 0.005% to 1.5%. Optionally, the weight percentage of the photosensitizer is 0.1% to 1.5%. More preferably, the weight percentage of the photosensitizer is 0.5% to 1.5%. For example, when the amount of the photosensitizer is less than 0.5%, the photosensitivity is too low; while when the amount of the photosensitizer is greater than 1.5%, the photosensitivity is too high, which is not conducive to obtaining high-resolution patterns.
[0034] Further, in one specific example, the photosensitizer may be selected from photoacid-producing agents. Photoacid-producing agents may include one or more of onium salts, nitrobenzyl compounds, diazo compounds, N-hydroxyimide sulfonates, and halotriazines. Specifically, they include, but are not limited to, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium perfluorobutyl sulfonate, bis(4-tert-butylphenyl)iodonium p-toluenesulfonate, p-nitrobenzyl alcohol, diazomethanealkyl compounds, diazonaphthoquinone sulfonate, N-hydroxynaphthoimide trifluoromethanesulfonate, and 2(4-methoxymethylvinyl)4,6bis(trichloromethyl)1,3,5-triazine. N-hydroxynaphthoimide trifluoromethanesulfonate is preferred.
[0035] In one specific example, the second solvent in the photoresist composition is one or more selected from ethyl lactate, butyl acetate, propylene glycol methyl ether acetate, methanol, ethanol, and propanol. Optionally, the solvent in the photoresist composition is propylene glycol methyl ether acetate (PGMEA).
[0036] In other specific examples, the photoresist composition also includes stabilizers, leveling agents, dispersants, or thickeners.
[0037] The stabilizer may include, but is not limited to, isoamyl alcohol, n-hexanol, glycerol, and n-hexane. The stabilizer ensures the chemical stability of the photoresist composition, maintains chemical balance, reduces the surface tension of the photoresist composition, and prevents photo-, thermal, or oxidative decomposition.
[0038] The leveling agent may include, but is not limited to, acrylic compounds, organosilicon compounds, and fluorocarbon compounds. The function of the leveling agent is to adjust the viscosity and flowability of the photoresist system, increasing the uniformity of film formation.
[0039] The dispersant can be a lignin sulfonate, such as sodium lignin sulfonate, calcium lignin sulfonate, and ammonium lignin sulfonate.
[0040] The thickener may include, but is not limited to, hydroxymethyl cellulose, sodium alginate, hydroxymethyl, hydroxyethyl cellulose ether, chitosan, polyacrylamide, etc.
[0041] The photoresist composition is used in photoresists, for example, in the preparation of photolithographic patterns. Specifically, when preparing photolithographic patterns, extreme ultraviolet lithography or electron beam lithography systems are used for exposure.
[0042] The above-described photoresist composition is applicable to various photolithography technologies, such as 254nm ultraviolet lithography, 365nm ultraviolet lithography, deep ultraviolet lithography, extreme ultraviolet lithography, or electron beam lithography. Preferably, because the metal-oxygen clusters in the above-described photoresist composition have a uniform crystal configuration and an extremely narrow grain size distribution, the above-described photoresist composition can exhibit extremely high resolution, and is particularly suitable for extreme ultraviolet lithography or electron beam lithography.
[0043] Furthermore, the present invention also provides a method for forming a photolithographic pattern, please refer to... Figure 1 It includes the following steps S100 to S400.
[0044] Step S100: Apply the photoresist composition according to the above embodiments onto the substrate.
[0045] Conventional equipment such as a spin coater can be used to apply the photoresist composition onto the substrate. Before application, the photoresist composition is preferably filtered using a filter with a pore size of 0.22 μm. The substrate can be a silicon wafer or a quartz wafer, or it can include silicon wafers or quartz wafers on which sensors, circuits, transistors, etc., are formed.
[0046] Step S200: Remove the solvent from the photoresist composition to form a photoresist film.
[0047] Specifically, the solvent in the photoresist composition can be removed by drying at a temperature of 50°C to 130°C for a time of 10s to 300s.
[0048] Step S300: Expose the photoresist film to radiation.
[0049] Specifically, the obtained photoresist film is exposed to radiation using an exposure system. The exposure system can be a 254nm ultraviolet low-pressure mercury lamp exposure system, a 365nm ultraviolet high-pressure mercury lamp exposure system, a deep ultraviolet lithography system, an extreme ultraviolet lithography system, or an electron beam lithography system. Specifically, the photoresist film can be exposed to electron beam radiation.
[0050] Step S400: The exposed photoresist film is developed using a developer to form a photolithographic pattern.
[0051] Specifically, when forming a photoresist pattern, a photomask is needed to block light to form the desired photoresist pattern. The developer can be one or more of the following: isopropanol, toluene, o-xylene, m-xylene, p-xylene, cyclohexane, n-heptane, n-pentane, 4-methyl-2-pentanol, propylene glycol methyl ether acetate, ethyl acetate, 1,4-dioxane, and butyl acetate.
[0052] Zinc oxide clusters with radiation-induced solubility transition characteristics, small particle size, and narrow particle size distribution were prepared based on the coordination interaction between monodentate ligands and metal-containing structural units (MBU).
[0053] The beneficial effects of this invention are: Since metal elements can enhance the etching resistance of materials, the development of metal-oxygen cluster (MOC) photoresists with high metal content has become a research hotspot in the field of high-resolution photolithography. However, the application of MOCs still faces the problems of large average size and wide size distribution, which makes it difficult to further improve the performance of photoresists. Metal-organic frameworks (MOFs) are constructed by bridging organic ligands with MBUs (such as metal ions or clusters). The MBUs are small in size (1~2 nm) and can provide metal elements with high etching resistance, thus they have the potential to be used in high-resolution photolithography. However, the MBU units in MOFs are usually coordinated by multidentate ligands and form insoluble coordination polymers, which are difficult to undergo solubility transition through radiation-induced transformation, thus limiting their application in the field of photoresists. Zinc has a higher extreme ultraviolet (EUV) absorption cross section than elements such as C, H, and O, and has low toxicity, thus it has the potential to be used to construct the host material of high-resolution photoresists. However, the large particle size, wide particle size distribution, and imperfect purity of zinc oxide clusters limit the further improvement of photoresist performance.
[0054] This invention prepares zinc oxide clusters with radiation-induced solubility transition characteristics, small particle size, and narrow particle size distribution based on the coordination interaction between monodentate ligands and MBU. The photolithographic performance of photoresists made with zinc oxide clusters prepared by this method as the main material is expected to benefit from the small particle size and narrow particle size distribution. Attached Figure Description
[0055] Figure 1 The molecular structure diagrams of the zinc-oxygen clusters obtained in Examples 1 and 2 are shown. Figure 2 The figure shows the thermal stability test results of the embodiment; Figure 3 The image shows the particle size test results for the example. Figure 4 This is a schematic diagram of the line array of the photolithography results for an example. Detailed Implementation
[0056] To facilitate understanding and implementation of the present invention, the following more specific and detailed embodiments and comparative examples are provided for reference. Through the description and performance results of the following specific embodiments and comparative examples, the various embodiments of the present invention and their advantages will become apparent.
[0057] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.
[0058] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.
[0059] The embodiments of the present invention are as follows: Example 1: Photoresist composition with benzoic acid-coated zinc oxide clusters as the main material (one) The synthesis of the zinc oxide cluster coordinated with methacrylic acid (compound A) is as follows: In a 150 mL flask, 4.0136 g (18.3 mmol) of zinc acetate dihydrate was dissolved in 15 mL of ethyl acetate, stirred and heated to 65 °C, and this solution was denoted as solution A. 4.4199 g (36.2 mmol) of benzoic acid was mixed with 2.8 g of triethylamine and dissolved in 15 mL of ethyl acetate, and this solution was denoted as solution B. Solution B was added dropwise to solution A. After the addition was complete, 15 mL of ethyl acetate was added to dilute the solution. The mixture was reacted at 65 °C for 24 h and then cooled to room temperature. The solution was left to stand at room temperature, and the product precipitated in crystal form within 2-3 weeks. The crystals were collected by filtration and dried in a vacuum oven at 60°C for 12 h to obtain compound A, which was then stored at room temperature in the dark.
[0060] The successful synthesis of this compound was characterized by infrared Fourier transform spectroscopy, nuclear magnetic resonance, and mass spectrometry. Its structure was characterized by single-crystal XRD (see appendix). Figure 1 The crystal structure of compound A indicates that this cluster contains two zinc atoms, bridged by four benzoic acid ligands, each additionally linked to an acetic acid ligand. Two triethylamine cations are also present as countercations. Thermal stability tests are attached. Figure 2 As shown in the figure, the initial weight loss of 5 wt% occurs at approximately 133℃, indicating good thermal stability and suitability for various photolithography processes. The particle size test results are as follows... Figure 3As shown, the average particle size of compound A is approximately 1.7 nm, indicating that compound A has a small average particle size and a narrow particle size distribution. (two) Photoresist composition: (1) Main material: zinc oxide cluster coordinated with benzoic acid (compound A) 20.0 mg (2) Photoacid-producing agent: N-hydroxynaphthalimide trifluoromethanesulfonate 3 mg (3) Organic base: Trioctylamine 0.1 mg (2) Solvent: 1 mL of propylene glycol methyl ether acetate Zinc oxide cluster photoresist with a concentration of 30 mg / mL was prepared using propylene glycol methyl ether acetate as a solvent: 30.0 mg of compound A and 0.1 mg of trioctylamine were weighed and dissolved in 1 mL of propylene glycol methyl ether acetate. The mixture was sonicated for 10 min, and then 3 mg of N-hydroxynaphthalimide trifluoromethanesulfonate was added. The mixture was sonicated for another 10 min. Other impurities were removed by filtering the mixture through filter membranes with pore sizes of 0.45 μm and 0.22 μm, respectively, to obtain the photoresist. The obtained photoresist was stored away from light.
[0062] Adding 2-3 drops of photoresist onto a silicon wafer and spin-coating it into a film, followed by exposure of the photoresist film using an electron beam direct writing device, ultimately yields a line array with a linewidth as narrow as 115 nm, which can meet the material requirements of advanced photolithography in my country (see...). Figure 4 df).
[0063] Example 2: Photoresist composition based on zinc oxide clusters coordinated with m-methylbenzoic acid as the main material (one) The synthesis of the zinc oxide cluster coordinated with methacrylic acid (compound B) is as follows: In a 150 mL flask, 4.0400 g (18.4 mmol) of zinc acetate dihydrate was dissolved in 15 mL of ethyl acetate, stirred and heated to 65 °C, and this solution was denoted as solution A. 4.9177 g (36.1 mmol) of m-methylbenzoic acid was mixed with 2.8 g of triethylamine and dissolved in 15 mL of ethyl acetate, and this solution was denoted as solution B. Solution B was added dropwise to solution A. After the addition was complete, 15 mL of ethyl acetate was added to dilute the solution. The mixture was reacted at 65 °C for 24 h, then cooled to room temperature. The liquid was left to stand at room temperature, and the product precipitated in crystal form within 2-3 weeks. The crystals were collected by filtration and dried in a vacuum oven at 60 °C for 12 h to obtain compound B, which was then stored at room temperature in the dark.
[0064] The photoresist of this invention is spin-coated onto a silicon wafer using a spin coater to form a photoresist coating. A dense line array pattern with a line width as narrow as 115 nm can be obtained by electron beam lithography.
[0065] The successful synthesis of this compound was characterized by infrared Fourier transform spectroscopy, nuclear magnetic resonance, and mass spectrometry. Its structure was characterized by single-crystal XRD (see appendix). Figure 1 The crystal structure of compound B indicates that this cluster contains two zinc atoms, bridged by four benzoic acid ligands, each additionally linked to an acetic acid ligand. Two triethylamine cations are also present as countercations. Thermal stability tests are attached. Figure 2 As shown in the figure, the initial weight loss of 5 wt% occurs at approximately 198℃, indicating good thermal stability and suitability for various photolithography processes. The particle size test results are as follows... Figure 3 As shown, the average particle size of compound B is approximately 2.1 nm, indicating that compound B has a small average particle size and a narrow particle size distribution. (two) Photoresist composition: (1) 20.0 mg of zinc oxide cluster coordinated with m-methylbenzoic acid (compound B), the main material. (2) Photoacid-producing agent: N-hydroxynaphthalimide trifluoromethanesulfonate 3 mg (3) Organic base: Trioctylamine 0.1 mg (2) Solvent: 1 mL of propylene glycol methyl ether acetate Zinc oxide cluster photoresist with a concentration of 30 mg / mL was prepared using propylene glycol methyl ether acetate as a solvent: 30.0 mg of compound B and 0.1 mg of trioctylamine were weighed and dissolved in 1 mL of propylene glycol methyl ether acetate. The mixture was sonicated for 10 min, and then 3 mg of N-hydroxynaphthalimide trifluoromethanesulfonate was added. The mixture was sonicated for another 10 min. Other impurities were removed by filtering the mixture through filter membranes with pore sizes of 0.45 μm and 0.22 μm, respectively, to obtain the photoresist. The obtained photoresist was stored away from light.
[0067] Adding 2-3 drops of photoresist onto a silicon wafer and spin-coating it into a film, followed by exposure of the photoresist film using an electron beam direct writing device, ultimately yields a line array with a linewidth as narrow as 127.9 nm, which can meet the material requirements of advanced photolithography in my country (see...). Figure 4 ac).
[0068] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A zinc-oxygen cluster, characterized in that, The general molecular formula of the zinc-oxygen cluster is Zn. a O b [A] c [B] d Where a takes values from 1 to 4, 1.5a≤b≤6a, c takes values from 1 to 4, d takes values from 1 to 4, A is the first organic ligand, B is the second organic ligand, and both the first organic ligand A and the second organic ligand B are organic groups; Furthermore, in the molecular structure of the zinc-oxygen cluster, 1 to 4 Zn atoms are connected to the first organic ligand A through surrounding O atoms, and the second organic ligand B is located at the Zn... a O b The two ends of the kernel are connected to individual Zn atoms.
2. The zinc-oxygen cluster according to claim 1, characterized in that, The first organic ligand A and the second organic ligand B together constitute the coordination moiety of the zinc-oxygen cluster. The first organic ligand A is selected from one or more substituted or unsubstituted aliphatic groups, and the second organic ligand B is selected from one or more substituted or unsubstituted aromatic groups.
3. The zinc-oxygen cluster according to claim 1, characterized in that, The zinc-oxygen cluster has a photoreactive group, wherein at least one of the first organic ligand A and the second organic ligand B has a photoreactive group; the photoreactive group is selected from one or more of carbon-carbon double bonds, acyloxy groups, acyl groups, aldehyde groups, ester groups, carboxyl groups, and amino groups.
4. The zinc-oxygen cluster according to any one of claims 1 to 3, characterized in that, The general molecular formula of the zinc-oxygen cluster is Zn2O8[A]4[B]2, Zn3O 12 [A]6 [B]2 or Zn3O 10 [A]6[B]2; The size of the zinc-oxygen cluster is 1 nm to 4 nm.
5. The method for preparing the zinc oxide cluster according to any one of claims 1 to 4, characterized in that, (1) Under the protection of an inert gas, a zinc salt solution is provided or prepared, the zinc salt solution comprising a first solvent and a zinc source dispersed in the first solvent; a ligand is added to the zinc salt solution and mixed evenly to prepare a zinc-containing reaction system; (2) Heating the zinc-containing reaction system, and during the heating process, the zinc-containing reaction system is reacted at a temperature of 20℃~120℃ for 12h~48h; (3) Stop heating, let stand until solid components precipitate, obtain the solid components by filtration and dry the solid components to obtain the zinc oxide cluster.
6. The preparation method according to claim 5, characterized in that, The zinc source is selected from one or more of alkyl zinc chloride, alkyl zinc oxide, hydroxyalkyl zinc chloride, and zinc salts; The zinc salt is selected from one or more of zinc carboxylate, zinc sulfonate, zinc alkoxide, zinc halide, zinc nitrate, and zinc sulfate; The zinc salt solution contains 40% to 80% zinc salt by mass. The first solvent is selected from one or more of alcohol solvents, ester solvents, hydrocarbon solvents, and benzene solvents; The ligand is selected from carboxylic acid ligands; The molar ratio of zinc atoms in the zinc source to the ligand is 1:(0.1 to 10).
7. The preparation method according to claim 5, characterized in that, During the heating of the zinc-containing reaction system, the zinc-containing reaction system is reacted at a temperature of 20℃~120℃ for 12h~48h to generate zinc oxide clusters; After stopping the heating of the zinc-containing reaction system, let it stand for 24 to 72 hours, and zinc will precipitate in the form of zinc oxide crystals.
8. The application of the zinc oxide cluster according to any one of claims 1 to 5 or the zinc oxide cluster prepared by the preparation method according to any one of claims 5 to 8, characterized in that, Applications in photoresist.
9. A photoresist composition, characterized in that, include: The second solvent and the photosensitizer and photolithography material dispersed in the second solvent, wherein the photolithography material comprises the zinc oxide cluster according to any one of claims 1 to 3 or the zinc oxide cluster prepared by the preparation method according to any one of claims 5 to 8; The photolithographic material accounts for 1% to 15% of the weight percentage in the photoresist composition, the photosensitizer accounts for 0.005% to 1.5% of the weight percentage in the photoresist composition, and the remainder is a second solvent.