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Self-organized pattern formation is a phenomenon that can be used for nanoscale pattering of large surface areas in a cost-effective manner. We exploit the phenomenon and fabricate sub-micron polystyrene wrinkle structures and demonstrate that after being coated with silver, they can be used as surface-enhanced Raman spectroscopy (SERS) substrates. We show that the signal enhancement generated by the wrinkles is 8 times higher in comparison to a flat reference while the measurement repeatability is simultaneously improved (variation reduced from 30 to 13%). The results indicate that selforganization could be further utilized in cost-effective, large-scale production of SERS substrates.

Abstract. In this paper, the results of exploiting self-organized sub-micron polystyrene (PS) wrinkle patterns possessing random orientation, in preparation of a nickel stamp for hot embossing purposes, are presented. Self-organized patterns were prepared employing a method in which a stiff cross-linked capping layer on the topmost part of the soft polystyrene layer was created by using reactive ion etching (RIE) device with mild conditions and argon as a process gas, and the wrinkle formation was initiated thermally. Different surface patternings were obtained using silicon and stainless steel (SST) wafers as substrates. Prepared Ni-stamps were employed in hot embossing of polycarbonate (PC) and cyclo-olefin polymer (COP) films, using a nano-imprinting process. The replication quality of the self-organized wrinkle structures in PC and COP films was monitored by comparing the shape and dimensions of the original and final surface structures. The hot embossed sub-micron scale features, originally formed on stainless steel substrate, were found to have influence on the optical properties of the PC and COP films by lowering their reflectances.

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