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CN-121559814-B - Ultraviolet curing nano-imprint photoresist with semi-interpenetrating network structure and preparation method thereof

CN121559814BCN 121559814 BCN121559814 BCN 121559814BCN-121559814-B

Abstract

The invention discloses an ultraviolet curing nano-imprint photoresist with a semi-interpenetrating network structure and a preparation method thereof, belonging to the field of ultraviolet nano-imprint photoresists. The invention obtains the semi-interpenetrating network structure without phase separation at the nanometer level by introducing hydrogen bond interaction among the components of the nano-imprinting photoresist, and successfully applies the semi-interpenetrating network structure to the field of nano-imprinting photoresist. The invention provides a new thought method for designing the nano imprinting photoresist with high mechanical property, and the semi-interpenetrating network structure improves the mechanical property and reduces the shrinkage rate of the photoresist to a certain extent. Compared with the nano-imprint photoresist in the prior art, the nano-imprint photoresist has the advantages of high mechanical property and low volume shrinkage, and can be used for efficiently imprinting the high-resolution nano-structure by a simple spin-coating film forming mode.

Inventors

  • WU SI
  • Che Hongyu

Assignees

  • 中国科学技术大学

Dates

Publication Date
20260512
Application Date
20260122

Claims (8)

  1. 1. The ultraviolet curing nanoimprint photoresist with the semi-interpenetrating network structure is characterized by comprising the following components in parts by weight: 50-95 parts of hydroxy acrylic ester monomer, 1-20 parts of sulfhydryl compound, 1-30 parts of linear polymer and 1-5 parts of photoinitiator; The linear polymer is one or more selected from poly (4-vinyl pyridine), poly (2-vinyl pyridine), polyamide, polyvinyl alcohol, polyacrylamide, polyurethane, polyurea and polyvinylpyrrolidone; The linear high molecular weight range is 1k-10000k; The hydroxy acrylate monomer is selected from the group consisting of 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, 2-hydroxycyclohexyl acrylate, 3-hydroxyadamantan-1-yl acrylate, pentaerythritol triacrylate, 3, 5-dihydroxyphenol methacrylate, 3-chloro-2-hydroxypropyl methacrylate, 2- (2-hydroxyethoxy) ethyl acrylate, 6- (4-hydroxyphenoxy) hexyl acrylate, 2- (2-hydroxyethoxy) ethyl methacrylate, 3, 5-dihydroxyadamantan-1-yl methacrylate, 4- ((4-hydroxyphenyl) sulfonyl) phenyl acrylate, 3- (acryloyloxy) -2-hydroxypropyl methacrylate, 2- (4-benzoyl-3-hydroxyphenoxy) ethyl acrylate, 2- (2- (2-hydroxyethoxy) ethoxy) ethyl methacrylate, 5-trifluoro-4-hydroxy-4- (trifluoromethyl) pent-2-yl methacrylate, 2- (2-hydroxyethoxy) ethoxy) ethyl methacrylate, 4-trifluoro-3-hydroxy-2-methyl-butan-3-yl methacrylate, one or more of glycerol dimethacrylate, poly (ethylene glycol) methacrylate and glycerol 1, 3-diglycerol alkyd diacrylate.
  2. 2. The semi-interpenetrating network structure ultraviolet curable nanoimprint resist of claim 1, wherein: The mercapto compound is selected from dithiothreitol, 2, 3-butanedithiol, 1, 2-ethanedithiol, 1, 8-octanedithiol, 1, 4-butanedithiol, 1, 6-hexanedithiol, 1, 5-dimercaptonaphthyl, 2, 4-dimercaptopyrimidine, 1, 4-benzenedimethanethiol, 1, 3-dimercaptopropane, 2, 5-dimercaptothiadiazole, toluene-3, 4-dithiol, 2, 3-dimercaptosuccinic acid, 3, 5-dimercaptobenzoic acid, 4', 4-dimercaptodiphenyl sulfide, 2, 3-dimercapto-phthalic acid, 2, 3-dimercaptopropan-1-ol, 2, 5-dimercapto-terephthalic acid, 4' -dimercaptopyrazoles, tetramercaptobenzene, pentaerythritol tetramercaptoacetate, 2, 6-naphthalenedithiol, 4' -dimercaptodiphenyl ether, 4' -thiodiphenyl mercaptan, biphenyl-4, 4' -dithiol, 1,3, 5-benzenetrithiol, trimercapto-s-triazine, 2, 7-naphthalenedithiol, 2' -dimercaptobiphenyl, 2, 5-dimercaptobenzene, 2' -dimercaptobyridine, 2, 5-dimercaptopyrazoles, dimercaptoacetylbenzene, 2, 6-dimercaptothhiothiophene, 3, 5-dimercapto-1, 2, 4-triazaheterocycle, dimercaptosilane, 2, 6-dimercaptopyridine.
  3. 3. The semi-interpenetrating network structure ultraviolet curable nanoimprint resist of claim 1, wherein: The photoinitiator is selected from one or more of benzoin dimethyl ether, 2-hydroxy-2-methyl-1-phenyl acetone, benzoin diethyl ether, dibenzoyl, diphenyl ketone, methyl o-benzoyl, 2-hydroxy-4- (2-hydroxyethoxy) -2-methyl propiophenone, 2-isopropyl-thioxanthen-9-one, 4-phenyldiphenyl ketone, methyl A-oxo phenylacetate, 2-hydroxy-2-methyl phenylpropane-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholin-1-acetone and 2, 2-dimethoxy phenyl acetophenone.
  4. 4. A method for preparing a semi-interpenetrating network structure ultraviolet curing nanoimprint photoresist according to any one of claims 1-3, which is characterized by comprising the following steps: Under the condition of no ultraviolet light, adding the linear polymer into the hydroxy acrylic ester monomer, stirring and dispersing until the linear polymer is completely dissolved in the hydroxy acrylic ester monomer, then adding the sulfhydryl compound under stirring, then adding the photoinitiator, stirring and dispersing uniformly, and filtering to obtain the semi-interpenetrating network structure ultraviolet curing nano-imprint photoresist.
  5. 5. The method of manufacturing according to claim 4, wherein: the filtering operation uses a 2000-2500 mesh screen for filtering.
  6. 6. A method for applying a semi-interpenetrating network structure ultraviolet curing nanoimprint resist according to any one of claims 1-3, comprising the steps of: Spin-coating the ultraviolet curing nano-imprinting photoresist with the semi-interpenetrating network structure on a silicon wafer after tackifying treatment to obtain a uniform photoresist film, filling the micro-structure gaps in the imprinting mold with the photoresist by applying a certain pressure, placing the mold and a square quartz plate in a vacuum environment for a period of time after full contact, removing residual air in the imprinting structure, taking out the mold and the square quartz plate, placing the mold and the square quartz plate in the ultraviolet irradiation center of 365 nm, and removing the mold after curing to obtain the photoresist with the needed imprinting structure.
  7. 7. The application method according to claim 6, wherein: The operation rotating speed of the spin coating is 500-5000 r/min, and the spin coating time is 10-600 s.
  8. 8. The application method according to claim 6, wherein: the light intensity of the ultraviolet light is 10-200 mW/cm 2 , and the light irradiation time is 1-300 s.

Description

Ultraviolet curing nano-imprint photoresist with semi-interpenetrating network structure and preparation method thereof Technical Field The invention belongs to the field of ultraviolet curing nano-imprint photoresist, and particularly relates to ultraviolet curing nano-imprint photoresist with a semi-interpenetrating network structure and a preparation method thereof. Background Nano-imprinting is an emerging high-resolution micro-nano manufacturing method and has important application prospects in the fields of integrated circuits, optical devices, biochips, flexible electronics and the like. Compared with the traditional photoetching, the nano-imprinting has the potential of exceeding the pattern resolution of the light diffraction limit in the traditional technology, can reach the sub-10 nm scale, provides a high-efficiency and low-cost technical scheme for manufacturing the nano-scale characteristic structure, and is suitable for large-area substrates, in particular for batch manufacturing of functional nano-structures. Nanoimprint lithography is a micro-nano fabrication method that transfers micro-nano structures on a template to a photoresist layer by means of mechanical imprinting in combination with an ultraviolet or thermal curing process. The nanoimprint can be classified into ultraviolet imprint and thermal imprint according to the curing manner of the nanoimprint resist. Hot embossing refers to using a thermoplastic material as the photoresist, starting the movement of the segments when the photoresist is heated above the glass transition temperature, applying pressure to transfer the pattern of the template into the photoresist, and cooling to fix the pattern. The rate of rise and fall can lead to significant efficiency degradation in the continuous manufacturing process, and the difference in thermal expansion coefficients of the mold and imprint resist can also lead to additional instability factors, while high temperatures can reduce the durability of the mold. In contrast, uv imprinting balances these problems well and is therefore more favored in the industry for uv nanoimprinting technology. Nanoimprint resist is a critical material in nanoimprint technology. For the design of high resolution nanoimprint resist, shrinkage is an important parameter that affects the fidelity of the imprinted pattern as well as the release of the mold. The shrinkage of the photoresist can lead to distortion of the pattern after imprinting, and meanwhile, the internal stress generated by shrinkage can increase the demolding force and increase the fracture risk of the photoresist. The shrinkage of nanoimprint resist is due to the fact that the distance between resist molecules is reduced from the van der waals distance before curing to the covalent bond distance after curing. From the standpoint of shrinkage alone, the smaller the shrinkage, the more advantageous the pattern fidelity and demolding process. There are many researchers focusing on shrinkage control. There are many methods currently available for reducing the shrinkage of nanoimprint photoresists, such as adding inorganic particulate fillers to the system, introducing reversible bonds such as disulfide bonds, introducing volume expanding monomers, reducing the concentration of photocuring groups, using flexible polymeric monomers, using step-wise polymerization, using pulsed UV curing, reducing the intensity of UV light, etc. Although there are many methods for reducing the shrinkage, it is difficult to control the photoresist not to generate shrinkage. In fact, high mechanical properties are an effective way to solve the problems of fidelity and mold release due to photoresist shrinkage. The higher modulus can resist the shrinkage stress in the material, so that the shrinkage phenomenon after imprinting is inhibited, and the pattern fidelity is improved. And the higher elongation at break and breaking strength give the material better fracture resistance in the demolding process. Therefore, under the action of better mechanical property, the photoresist can realize the imprinting process of the high-resolution structure only by controlling the shrinkage rate within a certain range. Traditional mechanical property improving means such as improving the crosslinking degree or using rigid monomers tend to reduce the elongation at break of the photoresist, while adding flexible monomers can improve the elongation at break but reduce the modulus and strength. It is difficult to solve the contradiction between strength, modulus and elongation at break. At the same time, increasing the degree of crosslinking or using rigid monomers also brings about a greater shrinkage, which to some extent may increase the risk of breaking the imprint pattern and the imprint mold. The semi-interpenetrating network structure is an effective method for solving the contradiction between strength, modulus and elongation at break in the high molecular field. The semi-interp