Microlens Excimer Laser Beam Shaping And Homogenizing Optical System

The spot shape of excimer laser is irregular, and the energy distribution isnon-uniform. According to analysis of characteristics of the excimer laser beamenergy distribution, a microlens laser beam shaping and homogenizing optical systemfor248nm excimer laser was invented. After shaping and homogenizing for248nmexcimer laser, a square spot with a high uniformity of the output beam is obtainedfinally. The size of the spot is about20mm×20mm. The spot energy uniformity error(process window) is less than±2%, and the top-hat factor of it is about0.90. Thelight energy loss rate of the entire system is about45%. Besides this, anothermicrolens laser beam shaping and homogenizing optical system for193nm excimerlaser was invented. After shaping and homogenizing for193nm excimer laser, asquare spot with a high uniformity of the output beam is obtained finally. The size ofthe spot is about15mm×15mm. The spot energy uniformity error (process window)is less than±1.5%, and the top-hat factor of it is about0.95. The light energy loss rateof the entire system is about35%. In addition, a set of scalable micron-levelmicro-lens shaping beam device for193nm excimer laser was designed. The mainresearch contents are as follows:First, the feature of excimer laser beam energy distribution was discussed. Thecolor image of an actual excimer laser energy distribution was captured. Then, weanalyze the image and extract relevant information using Matlab. At last we simulatethe actual excimer laser light source by the optical software ZEMAX. Because thespatial energy distribution of excimer laser is very complex, an optical simulation ofthis source is very difficult. This method provides a perfect solution to the aboveproblem. It also provides a technical foundation for the investigation on the opticalproperty of excimer laser and development of its optical components.Secondly, the research background and the design concept of microlens arraybeam homogenizers were discussed further. Then, by the simulation capabilities of theoptical design software ZEMAX, in the non-sequence mode, we simulate anddesign a shaping and homogenizing condenser for248nm excimer laser. Through theexperimental test, the homogenize capacity of the optical system is evaluated. Finally，a microlens laser beam shaping and homogenizing optical system for193nm excimer laser was designed by using the same design ideas and methods. On thisbasis, we made a in-depth research and analysis in the design and the features of thisoptical system，and a scalable set of micron-level micro-lens shaping beam device wasdesigned further.