Fabrication And Application Of Micro/nano-structure Based On Nanoimprint Lithography

As one of the key technique to lead the future science and technology revolution, nanotechnology has drawn great attention. In 1990 s, University of Minnesota proposed and developed a new nanotechnology called nanoimprint lithography(NIL) with high resolution, low cost, mass production, which becomes one of the most promising micro/nano-fabrication technologies. In this thesis, we mainly researched nanoimprint lithograpny and its applications in micro/nano structures and devices systematically. The work started from the process characteristics, study status, the key factors influencing the imprint process. By developing a new UV-curable nanoimprint resist based on the thiol-ene click reaction and analyzing its physical and optical properties, the structure design,fabrication and function verification of a new hybrid flexible imprinting mold based on thiol-ene resist were carried out through the related experiments. On the basis of the new resist and mold, a variety of novel imprinting technologies were developed by combining other fabricaton techniques to prepare high-resolution,high-aspect-ratio, special nanostrcutures with simple process and low cost. The novel imprint technologies were applied to fabricate the micro/nano structures and devices to realize the large production of micro/nano optical elements and the simple preparation of the surface enhanced Raman chips. This thesis provides the theoretical and technical guidance for the practical applications of NIL in the large-scale industrial production.The main contents and conclusions of the paper are listed as follows:(1) Based on the thiol-ene click chemistry reaction and the special performance requirements of nanoimprint resist, a UV-curable thiol-ene nanoimprint resist with excellent performances was developed. The parameters were measured, such as composition, mole ratio, viscosity, curing time, Young’s modulus. By analyzing the spinning, imprinting and etching properties, the compositons with the best performances were selected, with low viscosity(1~10cp), rapid rate of polymerization(within 1min), high Young’s modulus(0.1~5GPa), high resolution(sub-80nm). The applications of the thiol-ene resist were expanded in the optical field by researching the material surface modification and optical properties.(2) By combining the thiol-ene resist with excellent performances and hybridflexible mold with unique advantages, a new kind of hybrid flexible mold with thiol-ene structure layer was proposed. By carring out the experiments of structure design, fabrication and function verification, the large-area(3*3cm2) and high-resolution(sub-72nm) hybrid flexible molds were prepared with different elastic substrates. Based on the unique characteristics of hybrid flexible mold, the imprinting experiments on the curve surface were carried out. The high-resouiton grating and dot array were achived on a concave substrate to verify the conformal contact with the complicated surface, high resolution, high accuracy, and high fidelity of the hybrid flexible mold we fabricated.(3) Based on make full use of the excellent performances of thiol-ene resist, a variety of novel imprinting technologies were developed by combining other special fabrication techniques and optimizing the nanoimprint lithography. This paper mainly focused on a UV-curable double nanoimprint lithography based on the thiol-ene click reaction, fabrication of high-aspect-ratio nanostructure at the sacrifice of the nanoimprint mold, fabrication of special three-dimensional nanostructure by combining nanoimprint lithography and conglutination technology, and fabricaton of nano-channle based on the mold imprinting-induced cracking. These novle technologies prepare special nanostructures that only nanoimpirnt lithography is difficult to obtain, and break the limit of materials and techniques to further expand the applicaton space of the nanoimpirnt lithography.(4) Based on the unique advantages of nanoimpirnt lithography, its applications prospect in the fields of optics, electricity, magnetism, fluid mechanics, mechanical,and life science were analyzed systematically. The application researches on the micro/nano optical elements and surface enhanced Ranman chips were carried out using the developed novle imprinting technologies. The low-cost and small mass production of the micro/nano structures and devices was realized in the lab. This laid the foundation for the industrialization of the nanoimprint lithography in the industry.