Effects of Grating Marks Parameters on Lithography Alignment Precision

摘要

Effects of grating marks parameters on alignment precision and scope are investigated in this paper. In the lithography alignment method based on moire fringe, gratings are especially used as alignment marks. However, the rational design of grating marks for this approach to realize high-precision alignment is of great importance. In order to improve the feasibility of the alignment method, effects of several physical parameters of grating marks on alignment precision are analyzed by numerical calculation. The results imply that qualities of grating marks, such as size of period and ratio between two gratings, have an important impact on alignment precision and scope.