Nanoimprint technology has broken through the difficulties of traditional lithography in reducing feature size, and has the characteristics of high resolution, low cost, and high yield. selfSince its proposal in 1995, nanoimprinting has undergone 14 years of development, evolving into various imprinting techniques widely used in semiconductor manufacturing mems、 Fields such as biochips and biomedicine. Regarded as one of the top ten technologies that have changed humanity.
NIL embossing machineThe basic idea is to transfer the graphics onto the corresponding substrate through a template, and the transfer medium is usually a thin polymer film. The structure is hardened by methods such as hot pressing or irradiation to preserve the transferred graphics. The entire process includes two steps: embossing and graphic transfer. According to different imprinting methods,NIL can be mainly divided into three photolithography techniques: hot embedding, UV curing, and micro contact printing (uCP).

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The main function of a nanoimprint machine is to transfer the pattern onto the corresponding substrate. The transfer medium is usually a thin polymer film, which is hardened through methods such as hot pressing or irradiation to preserve the transferred pattern. Embossing technology is mainly divided into the following two types:

Hot pressing:Firstly, apply a thin layer of thermoplastic polymer material (such asPMMA）。 Raise the temperature and reach above the glass transition temperature Tg (glass transition temperature) of this thermoplastic material. Under high elasticity, thermoplastic materials are pressed onto a nanoscale mold and subjected to appropriate pressure. The thermoplastic material fills the cavity in the mold, and after the molding process is completed, the temperature decreases to solidify the thermoplastic material, resulting in a pattern that overlaps with the mold. Subsequently, remove the mold and perform various etching processes to remove residual polymers. Next, we will proceed with the graphic transfer. Graphic transfer can be achieved through etching or stripping methods. Etching technology uses thermoplastic materials as masks to perform anisotropic etching on the underlying substrate, resulting in corresponding patterns. The peeling process first deposits a layer of metal on the surface, and then dissolves the polymer with organic solvents. As a result, the metal on the thermoplastic material will also be peeled off, leaving the metal as a mask on the substrate. Then, etching is performed to obtain the pattern.

UV imprint:In order to improve the disadvantage of thermal deformation in hot stamping, the University of TexasC. G. Wilson and S v. Sreenivasan has developed Step Flash Imprint Lithography, which uses UV transparent quartz glass (hard mold) or PDMS (soft mold), and a low viscosity, light cured monomer solution for photoresist. First, drop a low viscosity monomer solution onto the substrate to be imprinted. Combined with microelectronics technology, the deposition of the thin film can be achieved by using a spin coating method. The template is pressed onto the wafer with very low pressure to disperse the liquid and fill the cavities in the template. UV exposure through the mold promotes polymerization and solidification of the polymer in the imprinting area. Finally, etch the residual layer and perform pattern transfer to obtain a high aspect ratio structure. The final demolding and graphic transfer process is similar to the hot pressing process.

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The inventor of this device was Stephen Y., the inventor of nanoimprint technology at Princeton University in the United States, from 2001 to 2003 Professor Chou's nanostructure laboratory, as a research assistant, conducted a 3-year research work and developed UV curable nanoimprint technology and materials, making important contributions to the development of nanoimprint technology. After joining the Department of Materials Science and Engineering in 2004, he continued to conduct research on nanomicrofabrication technology and nanoimprint technology, developed several new nanoimprint materials, developed new polymer imprint templates, and proposed curved nanoimprint technologyRice embossing technology; utilizeWith the support of the 863 project "Development and Application of Dual purpose Nanoimprint Equipment for UV Curing and Hot Pressing", a dual-purpose nanoimprint equipment with UV curing and hot pressing functions has been successfully developed. It has become a product and has been adopted by many universities and research institutions such as Nanjing University, Beihang University, University of National Defense Technology, Heilongjiang University, and Shenzhen Research Institute of the Chinese Academy of Sciences, forming a core nanoimprint technology with independent intellectual property rights. It has applied for and obtained multiple applications for China specific and US specific applications, and its technical level is synchronized with the most advanced international level in this field.