Polymer Sequence Alters Sensitivity and Resolution in Chemically Amplified Polypeptoid Photoresists.

Continuous progress in semiconductor technology relies on the ability to pattern transistors at sub-10 nm dimensions, necessitating the development of high-resolution photoresists for extreme ultraviolet (EUV) lithography. Chemically amplified resists, traditionally composed of multicomponent polymer systems, face increasing challenges at such patterning wavelengths due to nanoscale heterogeneity and stochastic defects. To address these limitations, this study explores polypeptoids, monodisperse, sequence-defined polymers─as a new class of photoresists with precise molecular control. Systematic variation of the polypeptoid chain length reveals a critical threshold necessary for successful pattern formation. Additionally, variations in monomer sequence strongly impact both photoresist sensitivity and feature fidelity, challenging conventional models that assume that sequence effects should average out across polymer chains. Finally, processing conditions such as postexposure bake temperature can be optimized to mitigate sequence-dependent variability. These results highlight polymer sequence as a powerful yet underexplored tool for tuning resist performance, offering a promising pathway toward improved nanoscale lithography.