The Fabrication And Application Of Micro/Nano Structures Based On Maskless Lithography

Advanced manufacturing technology for very large scale integrated circuit(VLSI)has closely reached the 10-nanometer(nm)resolution.However,due to its complexity,high-cost,and requiring expensive optical mask,traditional deep ultraviolet(DUV)immersion lithography is unsuitable for small-scale chips and devices or study of microscopic size effect,etc.In this thesis,the technologies of hybrid nano-imprinting and maskless lithography are used to fabricate a few kinds of micro-nano structures and devise,due to the simplicity,cost-effective,capacity to reproducing and fabricating sub-wavelength sized micro-nano structures,as follows:(1)We fabricate a large-area silicon(Si)nanopillar array with tens of nanometers in diameter,using a hybrid nano-imprinting technology.The nanopillar array is replicated from the structure of anodic aluminum oxide(AAO)porous array template.Since inhomogeneity in size of the fabricated nanopillar array,we make some modification to the obtained porous array via the plasma lateral erosion processing for achieving uniform Si-based porous array template.In addition,we prepare a subwavelength antireflective structure with low reflectance(Re)to the visible light(Re<5%)by the hybrid nano-imprint method.Compared with other techniques for fabricating anti-reflective surfaces,the hybrid nano-imprinting technology are promising for applying to the micro-nano optics due to advantages of large-area,high repetition rate,low-cost.(2)We explore applications of the DUV(266 nm)double-beam laser interference technology for fabricating the periodic micro-nano structures.It includes that response of the DUV chemical amplification photoresist to the light of the interference laser and influences of different experimental conditions on the morphology of resist layer.We fabricate large-area and uniform-morphology Si gratings with various periods by using traditional interference exposure process and replacing anti-reflective layer for interference exposure with total reflection metal layer.Furthermore,we fabricate hexagonal and tetragonal lattice structures using two dual-beam exposure process.(3)We fabricate diffraction imaging elements based on the computer generated holography(CGH)based on spatial light modulator(SLM),and reveal the relationship between pixel and diffraction imaging quality in holographic elements.Because of high fidelity,simplicity,low-cost,etc.,thermal nano-imprinting technology can achieve fast and accurate copy of the large-area diffractive imaging elements,which is expected to be applied in the field of security.(4)Fabrication of the Fresnel zone plate(FZP)via a combination of electron beam lithography(EBL)and reactive ion etching process(RIE).,and study the influence of focus position of the FZP on light-reflecting properties by experiment.Additionally,the numerical simulation of the FZP exhibits good focus property to the plane wave,and the sensitivity of photodetector could be greatly improved at the focal field of the FZP.