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Soft-graphoepitaxy using nanoimprinted polyhedral oligomeric silsesquioxane substrates for the directed self-Assembly of PS-b-PDMS

Research output: Contribution to journalArticleScientificpeer-review


Original languageEnglish
Pages (from-to)3512-3521
Number of pages10
JournalEuropean Polymer Jounal
Issue number11
Publication statusPublished - Nov 2013
Publication typeA1 Journal article-refereed


We report here the fabrication of periodic sub-25 nm diameter size cylinder structures using block copolymer (BCP) directed self-Assembly on nanoimprinted topographically patterned substrates. Tailored polyhedral oligomeric silsesquioxanes (POSSs) films were spin coated onto silicon substrates and were patterned by nanoimprint lithography to produce topographies commensurable with the BCP domain spacing. The chemistry of the POSS was tuned to control the alignment and orientation of the BCP films. The substrates were used to direct the microphase separation (following toluene solvent annealing) of a hexagonal structure forming polystyrene-block-polydimethylsiloxane (PS-b-PDMS) having a domain spacing of 42.6 nm and PDMS cylinder widths of 23.7 nm. On more hydrophilic POSS substrates the cylinders were obtained parallel to the substrate plane and aligned with the topography. In contrast, in more hydrophobic POSS patterns, the cylinders align perpendicular to the substrate plane. The use of these methods for the nanofabrication of vias, nanofluidic devices or interconnect structures of sub-25 nm feature size is discussed.


  • Block copolymer-Polyhedral oligomeric silsesquioxanes, Directed self-Assembly, Graphoepitaxy, Nanoimprint lithography, Surface chemistry