Research And Development Of Large-area Composite Nanoimprinting Lithography Tool

The patterning of LEDs, wafer level optical device, high efficiency solar cellpanels, high performance glass, HD flat panel display, etc., has a massive marketdemand for large-area micro/nanostructures. However, the existing micro/nanomanufacturing technologies is can’t better meet the needs of industrial-scaleproduction. Nanoimprint lithography (NIL) has been considered as one of the mostpotential large-area patterning processes. The current process however still face manychallenging issues such as large imprinting force, demolding difficulty, short life ofmold, the poorness of conformal contact between the mold with the non-flat substrate,etc. Therefore, it is necessary to develop new nanoimprint processes for patterningvarious uneven substrates over large area.A composite nanoimprinting process has been proposed by our research groupwhich has high potential to realizing large-area patterning for non-flat substrates bycombining the film-type composite mold, sequent micro-contact imprinting and peeldemolding. This thesis performs the research and development of a large-areacomposite nanoimprinting lithography tool based on the proposed nanoimprintingprocess.This thesis introduces the basic principle of the composite nanoimprintingprocess, completes the overall design of the composite nanoimprinting lithographytool. The proposed mechanical structure consists of imprinting module, wafer stage,mold delivery module, pneumatic system and framework. Furthermore, thepreliminary design for the control system of the nanoimprinting lithography tool areperformed.The demolding is the crucial step for the large-area composite nanoimprintingprocess. This has an important influence on the throughput, accuracy and quality. Thepeel demolding are profound investigated. A general model estimating demoldingforce was established based on the combination of the strain energy method and theconservation of energy in demolding stage. The required separating force for vertical demolding of grating patterns was achieved using the proposed model. Furthermore,the influence of the properties of mold materials and the aspect ratio of featurepatterns for peel demolding was revealed by numerical simulation using ABAQUSsoftware. These findings are valuable in providing a theoretical basis for large areaNIL, optimizing demolding process and further enhancing the performance of fullwafer NIL tool.The film-type composite mold is one of the most important process elements forthe composite nanoimprinting process, A new film-type composite mold is introducedwhich includes the patterning layer and support layer. This pattern layer adopts PVAwater-soluble materials. For the requirements of the patterning of high efficiency solarcell panels and anti-reflective glass, the pattern of the composite mold is optimized bythe finite time domain difference method (FDTD). A two-dimensional gratingmicro-nano pyramid structure with excellent antireflective characteristic is achieved.Finally, the manufacturing method of the composite mold is described.The mold delivery system of the imprinting tool plays an important role for theimprinting pattern quality. The mold delivery system is designed in detailed. Further,the scheme of the tension control is determined. An experimental setup of theimprinting tool was constructed.