URBÁNEK Michal Institute of Scientific Instruments of the AS CR, v.v.i.

Plasmonic Structures In PMMA Resist

Co-authors KRÁTKÝ Stanislav, ŠIMÍK Marcel, KOLAŘÍK Vladimír, HORÁČEK Miroslav, MATĚJKA Milan

Some metal material can exhibit special physical phenomenon which is called plasmon resonance. This effect can be used in optical applications where designed structures, using this effect, have special function as optical filters, polarizers, holograms etc. This papers deals with preparation of plasmonic structures in poly(methyl methacrylate) (PMMA) resist which is the most common material used for e-beam processing. Designed structures were prepared by e-beam writer with Gaussian beam and accelerating voltage of 100 kV. These structures are usually prepared into negative tone resist hydrogen silsesquioxane (HSQ). We prepared these structures by unusual way into positive resist PMMA due to unavailability and cost of HSQ resist. By this way we are able to achieve high resolution of structures suitable for special optical application. Exposed structures were developed in isopropyl based developer. Final structures after development were coated by two metal layers (first one is Ag layer, second one is gold) by magnetron sputtering and vacuum evaporation. The quality of prepared plasmonic structures was examined by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM).