10 nm lines and spaces written in HSQ, using electron beam lithography

Abstract

Hydrogen silsesquioxane (HSQ) is a high-resolution negative-tone inorganic resist with an established resolution below 10 nm. Using 100 keV electron beam lithography, we report the achievement of isolated 6 nm wide lines in 20 nm thick HSQ layers on silicon substrates. We also achieved 10 nm lines and spaces in a 10 nm HSQ layer. This is the smallest pitch (20 nm) achieved to date using HSQ resist. Experiments in order to investigate the effect of KOH based developer on ultimate resolution have been also performed and resulted in 7 nm wide lines. These results, in combination with the good etching resistance of HSQ, prove the versatility of HSQ for nanolithography.