NEMS structures on SOI by writing FIB implantation and subsequent anisotropic wet chemical etching

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 and subsequent anisotropic etching in KOH/H2O solution on Silicon-On-Insulator (SOI) substrates. Design and fabrication considerations to achieve freestanding Si structures, like nanowires and -bridges are discussed and some typical structures are shown. Electrical measurements are demonstrated which reveal a broad spectrum in the field of sensor applications.