Fabrication and evaluation of nickel-based high-k mask for high numerical aperture extreme ultraviolet lithography

We fabricated and evaluated a high-k mask using Nickel for high-NA EUVL. Since the absorber thickness of the high-k mask is much thinner compared to the Ta-based mask, the mask 3D effects are reduced resulting in improvement of imaging performance. It can resolve 10 nm half-pitch L/S pattern for all the leading candidate systems of 0.55NA EUVL. Also, it is optimized for dry etching and wet cleaning process due to the insertion of CrN spacer layers. We suggest this Ni-based high-k mask for the high-NA system since this exhibit improved imaging performance and easier manufacturability.