Enhancement of the nanostencil method and its applications

Increased flexibility in patterning becomes important for the engineering of advanced nano/micro-electro-mechanical systems (NEMS/MEMS). Surfaces to be structured are either mechanically unstable and/or (bio-) chemically functionalized, such as ultra-thin solid-state membrane and cantilever devices, polymer-based devices, micro/nanofluidics, and bio-analytical systems. The key aspect in the near future is to find new ways to tie top-down and bottom-up methods together, and to connect structures across the nano/microgap. Nanostencils have the versatility and multiple length-scale capabilities to be able to bridge the nano and micro world. In addition, contrary to soft-lithography and nanoimprint lithography, the nanostencil method has the potential of contactless patterning. This enables the patterning of either very fragile, (bio-) chemically functionalized as well as non-planar surfaces. Although the principle of shadow evaporation through masks is known for some decades, the method still needs maturation in length scales, membrane size, membrane stability, and reusability possibilities. We will present our progress in producing full-wafer, stabilized stencils with multiple length scales (between 50 nm and several 100 microns) and its consequences for alignment and cleaning possibilities. Examples of applications of the stencils will be given in the field of MEMS and nanotechnology, such as NEMS devices, direct patterning of thin films, functional SAM layers for MEMS, nanowires, and nanoscale Hall-probes.