Incorporating metals and halogens into polypeptoid-based photoresists for extreme ultraviolet lithography.

Polymers have long played a critical role in patterning silicon to create microelectronic devices. However, as state-of-the-art “extreme ultraviolet” (EUV, 13.5 nanometer wavelength) photolithography tools now allow for patterning of sub-10 nm features, polymeric photoresists face significant challenges with stochastics and sensitivity. To address these, we have developed polypeptoid-based photoresists to investigate the effects of polymer sequence and dispersity on patternability. In traditional polymeric systems, dispersities in molecular weight, composition, and sequence are compounded by material inhomogeneities in photoresist formulations and poor EUV photon absorption, contributing to unacceptable patterning defects. Sequence specificity of the peptoid system eliminates these variations, enabling precise study of the effects of polymer sequence and dispersity on patternability. Incorporation of metals and halogens probes the impacts of strongly EUV-absorbing elements on photoresist sensitivity at industrially relevant conditions.