Extreme-ultraviolet (EUV) lithography underpins continued device miniaturization, yet conventional photoresists suffer from stochastic issues and the resolution-sensitivity-roughness trade-off at sub-10 nm dimensions. Herein, we present a modular synthetic platform based on sequence-defined peptoids to overcome these limitations. In this work, two distinct oligopeptoid architectures were explored. The first employs a chemical amplification mechanism, using Boc-protected side chains to trigger solubility switching upon acid-catalyzed deprotection. Their lithographic performance, using either ionic or non-ionic photoacid generators (PAGs), was evaluated under deep-ultraviolet (DUV) exposure. The second is a creative innovation in which non-ionic PAGs were covalently tethered onto peptoid backbones via copper-catalyzed azide-alkyne cycloaddition, making the PAG itself the solubility-switch moiety and ensuring uniform acid distribution. We further extent the platform to peptoid-b-PMMA block copolymers for directed self-assembly (DSA) lithography via ATRP “grafting-from” and RAFT-amidation routes, addressing polymerization control and purification challenges. Together, these studies provide a foundation for a highly tunable, molecularly uniform photoresist framework and demonstrate initial compatibility with both EUV patterning and DSA process, although further optimization remains necessary.