Large-area ITO And TFT Lithography Using Excimer Laser Projection And Scanning System

As an important process in production of flat panel display, the importance of lithography is obvious. Large area and high resolution is the development trend of flat panel display. The main topic of this article is the study on large area ITO and TFT lithography using excimer laser projection and scanning system.On the premise of efficiency, we proposed a scanning method to improve the uniformity, which can compensate the exposure value error from the X and Y dimensions due to scan error and step precision error. The results showed that the uniformity was improved by1.5percent.After investigation we found that the20μm feature size of ITO subpixel electrode can meet the requirements of the flat panel display in the future. ITO glass are used for test the exposure machine. Best experimental parameters were obtained throught other related photolithography steps and the10μm、15μm and20μm linewidth pictures from the optical microscope were analysed combined with ZEMAX and MATLAB software.An American photolithography objective patent (US Patent#5805344) was selected as an initiating structure to optimal design for the lithography of tablet personal computer. The optimization results were analysed from different angle by optical simulation software ZEMAX, such as OPD、 MTF、 PSF and so on. The results showed that OPD was smaller than？/4, maximum field curvature was smaller than5μm and maximum distortion was smaller than0.0004%. The resolution reached to2.5μm.Finally, we introduced the the maskless photolithography and analyzed the principle of lithography based on DMD and its advantages especially. The method has the advantages in the production of flat panel display industry in the future.