ICP cryogenic dry etching for shallow and deep etching in silicon

We achieved to etch nano- and deep structures in silicon using ICP-cryogenic dry etching process. We etched nanopores and nanocantilevers with an etch rate of 13 nm/min, nanopillars with an etch rate of 2.8 μm/min - 4.0 μm/min, membrane and cantilever structures with an etch rate of 4 μm/min and 3 μm/min, respectively. Nanopores and nanocantilevers are interesting structures for Bionanoelectronics. Nanopillars can be used as substrates/templates for the MOCVD growth of GaN nanoLEDs. They are the basic constituents of a nanoparticle balance and also of a thermoelectric generator. For the joining of the silicon wafers of the thermoelectric generator the low temperature joining technique can be used. Cantilevers can be used for sensing, e.g. as tactile cantilevers. They can be used also as resonator for mass sensing even in the subnanogram region. The actuation of the resonator can be done by using piezoelectric thin films on the cantilevers. The mass detection depends on the resonance frequency shift caused by loaded mass on the cantilevers. Such cantilevers are robust and easy to produce. The deep etching in silicon was done by using a photoresist mask and creating perpendicular and smooth sidewalls.