| Maskless lithography is one of the important directions of lithography technology.Using maskless lithography to make mask pattern is needless to make expensive photomask,but just change the corresponding mask pattern in the computer,which is particularly suitable for the complex mask graphics.The lithography is a hotpot both in industry and academia in recent years.Based on the digital maskless lithography technology,a new method of photolithography is proposed.This paper designs and develops a maskless lithography system based on DMD(Digital Micro-mirror Device).DMD is used as a spatial light modulator to generate digital mask graphics,greatly reduces and simplifies the lithography process.This technology owns obvious advantages such as flexible,fast,low-cost and so on,compared with other lithography technology.The contents of this paper are as follows:Firstly,we determine the overall framework of DMD lithography system,describe the principle of the system.The system is composed of four parts:LED illumination system,mask generation,imaging system,automatic pose regulating system.We analysis and design each part of the system.We use ZEMAX to design and develop an UV-LED illumination system,which illuminative uniformity of LED illumination system is more than 90%;Moreover,we design and develop a coaxial automatic pose regulating system,which greatly improve the accuracy of the substrate posture adjustment.Secondly,based on the basic knowledge of optical mechanical and optical calibration method,we install the components of the lithography system and test the system.Best work parameters are determined by a lot of experiment.Meanwhile,we can achieve the stable structure with feature size of 2?m.Based on this system,large area graphical exposure technology can be achieved by using the high precision six-axis translation stage,with the image stitching error less than 2?m.Finally,we analyze systematic error mainly from the optical path system,the imaging system and the assembly process. |
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