EUV attenuated phase shift mask: development and characterization of mask properties

Toward logic 3nm and beyond, mask 3D effect and stochastic failure are main issues in EUV lithography. Alternative absorber material is required to mitigate those issues. EUV attenuated phase shift type absorber with low n value enables to achieve higher NILS due to phase cancellation effect. And much better imaging performance can be expected. We developed candidate attenuated phase shift type absorbers and evaluated these blank and mask properties. In this paper, we will report on those blank and mask properties for the candidate phase shift type absorbers.