Phase retrieval algorithms for patterned mask metrology in EUV
Paper 9635-14
Time: 4:40 PM – 5:00 PM
Author(s): Rene A. Claus, Yow-Gwo Wang, Univ. of California, Berkeley (United States); Antoine J. Wojdyla, Markus P. Benk, Kenneth A. Goldberg, Lawrence Berkeley National Lab. (United States); Andrew R. Neureuther, Univ. of California, Berkeley (United States); Patrick P. Naulleau, Lawrence Berkeley National Lab. (United States); Laura Waller, Univ. of California, Berkeley (United States)
We evaluate the performance of several phase retrieval algorithms applied to aerial image measurements of patterned EUV masks. Patterns present a challenge for these algorithms due to the higher contrast images and stronger diffraction. For this study we looked at the ability to correctly recover phase when a multilayer defect was in the presence of line-space patterns. We also applied the algorithm to aerial image measurements of an etched EUV phase shift mask. Measurements were taken on the SHARP EUV microscope at Lawrence Berkeley National Laboratory.