Defect inspection and repair performance comparisons between EUV and conventional masks

摘要

Two types of blanks, EUV A and EUV B, are the leading EUV blanks contenders. They are evaluated and compared with OMOG blank for their suitability as a photomask blanks. For defect inspection evaluation, contrast for pattern image and sensitivity for detection were evaluated using the newly developed inspection tools. With these tools, it is learnt that the sensitivity varies according to a set of conditions. For repair performance evaluations, EUV mask was assessed through E-beam repair tools, those that are most widely used. The results on both types of masks demonstrate good repair shape that is almost same quality as repair on OMOG mask. Moreover, under the two types of repair conditions used in this study, no degradation on pattern was found for the optimized condition as result of repair work.