Analysis and applications of nanostructures created by stencil lithography

We present an analysis on the blurring, electrical and optical properties of nanostructures fabricated by stencil lithography and their application for biomolecular sensing. We analyze the effect of the stencil-substrate gap on the blurring, then we present the fabrication and electrical characteristics of nanowires on plastic substrates, and finally, we demonstrate the application of nanodots for biomolecular detection based on plasmon resonance. To study the effect of the gap, we have designed and fabricated stencils having plateaus with apertures at different heights. The measured blurring of the structures is ~200 nm for a 40 mum gap. We have also observed a decrease in the thickness of the structure as the gap increases. Using stencil lithography, we have fabricated Au nanowires and arrays of Au nanodots. The nanowires were deposited on plastic substrates, having widths down to 80 nm and lengths up to 20 mum. The electrical resistivity of the wires is 7-10 muOmegacm. Finally, we have deposited Au nanodot arrays on glass and silicon substrates. The arrays contain nanodots 65 nm and 100 nm in diameter with different spacing between them. The localized surface plasmon resonance wavelength of the dots is ~800 nm. These arrays have been successfully used as biosensors, showing a resonance wavelength shift when biomolecules bind to the structures.