Nano-structures for sensors on SOI by writing FIB implantation and subsequent anisotropic wet chemical etching

Freely suspended Si nanowires and nanobridges have been fabricated on silicon-on-insulator substrates by patterned FIB Ga⁺ implantation and subsequent wet chemical etching. This technology is combined with classical microelectronic processing steps of photolithographic patterning and broad beam ion implantation to position and integrate the nanostructures into current technological platforms and therefore to increase the fabrication efficiency. Design, performance and fabrication considerations to achieve free-standing Si nanostructures are discussed and some typical examples are shown. Static and dynamic electrical measurements are presented, including I–V characteristics and displacement excitation by applying an AC voltage. The temperature dependence of the electrical resistance of Si nanostructures is demonstrated, which reveal, for example, the applications as nanowire thermal sensors.