Influence of Polymer Structure on E-Beam Lithography: Minimizing Line Edge Roughness with Bottlebrush Polymers

This research comprehensively compares commercial linear polymers and synthesized bottlebrush polymers to discern the structural impact of poly methyl methacrylate resists on electron beam (e-beam) lithography. It is consistently acknowledged in the literature that the entangled structure inherent to high molecular weight linear polymers plays a pivotal role in improving both line edge roughness (LER) and the associated contrast value. In contrast, bottlebrush polymers, devoid of such entanglements, invariably show diminished LER while presenting increased contrast after development. This behavior is hypothesized to arise from the bottlebrush polymer's low energy demand for chain scission reactions, attributed to its highly stretched backbone, which necessitates lesser energy for detachment. To deepen our insights, a coarse-grained simulation model was employed to elucidate the molecular dynamics of the polymers during the developmental phase. Cumulatively, these observations emphasize the significance of considering molecular structures in lithographic techniques to optimize resolution and pattern accuracy.