Crossbeam processing for nano-structures on SOI substrates


Crossbeam processing for nano-structures on SOI substrates

Bischoff, L.; Schmidt, B.; Lange, H.; Donzev, D.

The further miniaturization of silicon nanomechanical structures in combination with the highly developed microelectronic technology at the micro- and nanometer level will lead to a new generation of nano-electro-mechanical systems (NEMS). A modern technique to fabricate such three-dimensional structures is the combination of high-concentration p-type doping of silicon by high resolution writing implantation using a focused ion beam (FIB) and subsequent anisotropic and selective wet chemical etching. FIB-patterned and chemically etched 3D Si structures with nanoscale thickness and width have been fabricated using 30 keV Ga+ ion implantation (CANION 31Mplus and NVision40) followed by an anisotropic etching in KOH/H2O solution on Silicon-On-Insulator (SOI) substrates. This technology is combined with classical microelectronic techniques, like lithography and broad beam implantation working on a 4 inch wafer to increase the fabrication efficiency especially for the contact areas. Design, performance and fabrication considerations to achieve freestanding Si structures, like nanowires (NW) and -bridges are discussed and some typical structures are shown. Static electrical measurements are demonstrated among others a nano-thermometer, which reveal a broad spectrum in the field of sensor applications. To reduce the resistance the amorphous Si-NWs were covered by electron beam assisted deposition of a 30 nm Platinum film. The dynamic behaviour like resonance frequency was determined by AC excitation and laser interferometer measurements.

Keywords: FIB; etching; SOI wafer; nanowire; NEMS

  • Lecture (others)
    4. FIB-Workshop, Focused Ion Beams in Research, Science and Technology, 29.-30.06.2009, Halle/Saale, Deutschland

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Publ.-Id: 12854