Study Of Gratings Fabricated By UV-LIGA Technique

Grating is composed of many grid lines in parallel, usually widely applied as the core device inthe field of communication, optical storage and spectrum analysis, playing the function of dispersion,beam splitter, polarization and phase matching. At present, the main methods of grating fabricationinclude: mechanical characterization of holographic lithography, nanoimprint lithography, electronbeam lithography, X-ray lithography, UV-LIGA technology. But photoresist develops difficulty whenthe grating getting a certain thickness by the UV-LIGA technology. At the same time as SU-8photoresist has obvious swelling in the electro forming, there will be size deviation between the widthof grating structure grid line and the width of mold trench line before electroforming, which has anegative impact on the grating structure building by the UV-LIGA technology.The research object of this paper is the grating, and the paper introduced ultrasonic vibration onthe progress of technology by the UV-LIGA on the base of SU-8photoresist, optimized the process,successfully completed the preparation of the grating of the nickel base. The main work is as follows:(1) The selection and optimization of the parameters of the lithography process. With thecombination of SU-8photoresist lithography process, analyze the affect to the final quality of theplastic mold of the spin coating before baking, exposure, post bake of different parameters, anddetermine the specific process parameters of the preparation of65μm thick lithography plasticmold through a pilot study.(2) The use of ultrasonic-assisted developing technology. It studied the effect to developing quality ofthe plastic mold of ultrasonic-assisted, and tested contrast grating plastic mold developing quality,analysised different ultrasonic power affect to the quality of the plastic model, and the resultsshowed that the most appropriate is35w ultrasonic-assisted developing power.(3) The research of ultrasonic vibration. Through the introduction of ultrasonic vibration to explorethe impact of ultrasonic on the photoresist mold swelling after baking, before developing, anddetermine the suitable ultrasonic time and power through the test.(4) The parameters test of micro electroforming. Through simulation analysis of two impact fluidway on the results of the electroforming compared, it determined the selection of the lateralimpact liquid device to carry out the electroforming test; analysisd the current density, thethickness of the plastic mold,impact liquid velocity, temperature and other electrical casting themain process parameters on the preparation of a nickel-based raster and specific test parametersdetermined by experiments.