Development of stencil lithography for nanopatterning and for electronic and biosensing applications

This work presents analyses and developments in nanofabrication using stencil lithography and its application for electronics and biosensing. Metallic nanostructures are fabricated using stencil lithography studying the pattern transfer from the stencil to the substrate. The physical properties of the deposited nanostructures are analyzed, namely those relevant for electronics and biosensing. Applications of stenciled nanostructures for biosensing are studied based on localized surface plasmon resonance in metallic nanoparticles, and on impedance measurements on discontinuous films. The clogging of the nanoapertures in the stencil due to the accumulation of material on the membrane and its effect on the deposited structures are analyzed. A method to unclog the nanoapertures based on metal wet etching is presented, allowing the reutilization of the stencils. The blurring of the deposited structures related to the stencil-substrate gap, the divergence of the material flux and the surface mobility of the deposited adatoms is analyzed. The obtained results show that the blurring can be reduced optimizing different deposition parameters such as the thickness, temperature and deposition rate. The systematic fabrication of