Dongqing Zhang, Xiangzhao Wang, Weijie Shi. A novel method to determine the FOCAL energy range[J]. Chinese Optics Letters, 2005, 3(10): 10589
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Determination of the energy range is an important precondition of focus calibration using alignment procedure (FOCAL) test. A new method to determine the energy range of FOCAL off-lined is presented in this paper. Independent of the lithographic tool, the method is time-saving and effective. The influences of some process factors, e.g. resist thickness, post exposure bake (PEB) temperature, PEB time and development time, on the energy range of FOCAL are analyzed.