Optimization Of The Maskless Digital Micromirror Lithography System And The Lithography Process

Maskless lithography technology based on Digital Micromirror Device(DMD),has an unique digital image generation function and an unique UV selective exposure characteristics of photoresist.Therefore,it can realize the visual lithography of what you see is what you get,especially it can meet the needs of scientific research-level lithography instruments with flexible and diverse lithography images.In recent years,the integration of small desktop with high resolution and high efficiency is one of the development trends of maskless digital lithography system.In this thesis,aiming at solving the problems of low lithography efficiency,low lithography resolution,single function of lithography software in the existing maskless lithography system,as well as the problems existing in the subsequent lithography process,we put forward the solutions and carried out the work.The main contents include the following aspects:(1)Optimization of optical path.Aiming at solving the problem of low lithography efficiency of DMD maskless lithography system,the influence of optical path structure and optical component selection on lithography efficiency is further studied: serious loss of light energy caused by too much light path folding and low photolithography efficiency caused by low light source intensity and other reasons;the re-selection of some of the optical components and optimization of the optical path to improve lithography efficiency and lithography resolution.(2)Addition of lithography software functions.In view of the single function of the control software of the lithography system built in the early stage,some auxiliary functions are added on the original basis,mainly including the function of lithography pattern rotation and adding text annotation,and other auxiliary functions of controlling software coordinate recording and lithography pattern position preview.(3)Performance tests of photolithography system.To perform photolithography quality verification experiments on the optimized DMD Maskless photolithography system,mainly to test the efficiency of exposure and minimum resolution of the photolithography system,adopting wobble photolithography technology to optimize the edge zigzag of the photolithography pattern and improve the photolithography resolution capability,and three-dimensional photolithography based on pulse width gray scale modulation.Coating AZ MIR 703 positive photoresist on a 300 nm thick silicon dioxide substrate,with a single area of exposure 1305 ?m ×735 ?m,only 0.5seconds exposure time,and the resolution capability of the photolithography system reaches sub-micron level.(4)Research on the process of metal stripping and removing photoresist.In view of the difficulty of metal stripping and removing process,a double-layer adhesive metal stripping and removing process is proposed to improve the success rate of metal stripping and the removing of photoresist and to realize the minimum resolution.It mainly examine the effects of the baking conditions,exposure and development time of the double-layer photoresist on the structure of the double-layer photoresist and its procedure of metal stripping;the comparison between the double-layer photoresist metal stripping process and the single layer photoresist metal stripping process.We optimizes the photolithography system,and establishes a set of fast and efficient,convenient and applicable miniaturized maskless photolithography system.