Synthesis and evaluation of novel organoelement resists for EUV lithography

Abstract

EUV lithography is to date the most promising NGL technology for the sub-50nm technology node. In this work, we have designed and synthesized several types of organoelement resists with minimum oxygen content for high transparency. Either silicon or boron was incorporated in the resist structures to improve both etch resistance and transparency. In the exposure studies, it was possible to image the silicon-containing polymers to 22.5 nm line/space patterns using EUV interferometry. A second type of EUV transparent resist platform was studied involving boron-containing polymers. Carborane carboxylic acid was attached to a copolymer backbone to introduce boron atoms with controlled attachment level. In a preliminary study, these polymers could be imaged by 248nm exposure. Effect of structure on line edge roughness is also be included in the discussion.