The Development Of Two Beam Laser Interference Nano Lithography Equipment

Nano lithography equipment is the key equipment in nanotechnology industrialization.It not only meets the requirements of the research of photonic crystals and low dimension quantum materials but also meets the industrialization needs of LED patterned substrate and textile structure on the surface of solar cells from micrometer to nanometer scale.However,due to the restriction of lithography capability and process cost,there is a lack of low cost nano lithography equipment for preparing large area periodic nano pattern structure with high uniformity of size and shape.Laser interference lithography is very suitable for the fabrication of periodic nano pattern structure with the advantage of large area,high resolution,high uniformity and low cost.The main content of this thesis is about developing a laser interference lithography system,and the objective of this research is to fabricate large area and high resolution nano periodic gating or nano periodical dots with low cost.This thesis mainly includes five parts.The first part is the introduction introducing a number of lithography methods,including traditional UV lithography,projection lithography,EUV lithography,electron beam lithography,focused ion lithography,nano imprinting lithography and laser interference lithography.By analyzing and comparing these micro and nano fabrication technologies that are utilized for fabricating nano periodical pattern,the unique advantage of laser interference lithography for fabricating nano pattern is high efficiency,low cost and large area.The second part is the theoretical analyzation for laser interference system.Based on the diffraction theory of light,the mathematical and physical model of two-beam laser interference system is built,and simulation software is used to simulate the intensity distribution in the lithography area.The third part is the experiment of establishing a two-beam laser interference lithography platform.Through the method of combining theoretical model with experiment confirmation,under the circumstance of adding less system complexity,choosing suitable system components are chosen and two-beam laser interference lithography system is built.The fourth part is the experiment of fabricating periodic nano pattern.The experiment contents are to use the established platform to do exposure experiments on the the surface of silicon wafer(2-4 inch)coating positive resist,and to develop it in specific development solution by combining several characterization methods to analyze the quality of lithography pattern.The fifth part is the conclusion and outlook.The following is the conclusion of the research content and experiment results.1.Under the founding of Chinese Academy of Sciences research program equipment development program,a self-built two beam laser interference lithography system is done.Through the overall shock design,lithography system possesses the strong ability of the resistance of outside shock and noise.and a high beam uniformity on a larger area was realized through the parallel homogenization of laser beam.2.The homogeneity of the dots is excellent.The cycle range of pattern is from 500 nm to 1.2?m,and the lithography size is up to 4 inch and is able to enlarge to 8 inch.