Research On The Equipment For Hot Embossing And Related Experiments

At present, due to the restriction of light wavelength and numerical aperture, the key technology for fabricating optoelectronic devices —optical lithography is difficult to obtain sub-100 nm patterns. Nano Imprint Lithography (NIL) is a promising technology which can fabricate micro/nano structures and devices with high resolution, low cost, and is easy to realize mass production. It is based on mechanical deformation of the resist shape by using a mold pressing into the resist film. Therefore, its resolution is independent of many factors that restrict the resolution of conventional lithography, and can break the resolution limit of conventional photolithography. In addition, because of its capability to replicate nanoscale patterns repeatedly in a large area with fair uniformity, NIL possesses the advantages of low cost and high throughput. Main achievement and creative work presented in this thesis are summarized as follows: First, this thesis introduces nanoimprint lithography technology including mold preparation, resist option and imprint process. Next, its working principle is dealt with in detail, involving in modeling the time and speed of hot embossing based on the flow behaviour of polymers. Second, based on the process research, we have developed a nano imprint lithography setup which can easily realize both hot embossing and UV-imprint lithography by changing different modules. And adopting X-Y-θstage with both macro and micro actuators to achieve coarse and fine positioning alignment, this machine can reach 20nm positioning resolution within the work range of 150×150mm. Therefore, it can satisfy the need of muti-layers and muti-steps imprint. Finally, we have conducted imprint experiments using the homemade equipment, and fabricated some micro/nano optical structures, such as 50μm diameter and 60μm pitch micro-lens arrays, 80nm line width and 500nm pitch nano gratings, 200nm diameter and 300nm pitch nano dots arrays, etc. On the basis of the experiments, this thesis generalizes proper imprint process and process parameters. In addition, this thesis analyzes and optimizes printing temperature and pressure which significantly affect the pattern transfer fidelity. This thesis aims at providing a sort of nanofabrication technology, and pushing the industrialization of nano devices such as nano optoelectronic devices, nano magnetic memory devices, micro fluidic devices, and so forth.