Defect avoidance for extreme ultraviolet mask defects using intentional pattern deformation

Extreme ultraviolet lithography has been adopted as the next generation lithography solution to sub 10nm technology node. However, mask blank defect is a major challenge for this technology. In this work, we explore the extended benefits of utilizing pattern deformation for EUV mask defect avoidance. In the first part of the paper, we propose a constraint programming based method that can explore pattern shift, small angle rotation, and deformation for defect avoidance. In the second part of the paper, we utilized this proposed method to explore the benefit of pattern deformation. For an 8nm polysilicon layer of an ARM Cortex M0 layout, pattern deformation combined with pattern shift was able to improve mask yield by more than 90%-point compared to pattern shift alone for a 40-defect mask.