Sub-10 nm patterning using EUV interference lithography

Abstract

Extreme ultraviolet (EUV) lithography is currently considered as the leadingtechnology for high-volume manufacturing below sub-20 nm feature sizes. In parallel,EUV interference lithography based on interference transmission gratings hasemerged as a powerful tool for industrial and academic research. In this paper,we demonstrate nanopatterning with sub-10 nm resolution using this technique.Highly efficient and optimized molybdenum gratings result in resolved line/spacepatterns down to 8 nm half-pitch and show modulation down to 6 nm half-pitch.These results show the performance of optical nanopatterning in the sub-10 nmrange and currently mark the record for photon-based lithography. Moreover,an efficient phase mask completely suppressing the zeroth-order diffraction andproviding 50 nm line/space patterns over large areas is evaluated. Such efficient phasemasks pave the way towards table-top EUV interference lithography systems.