Silicon nanowire fabrication using novel hydrogenation-assisted deep reactive ion etching

A novel method for the fabrication of silicon nanostructures on silicon substrates is reported. This technique relies on a hydrogenation-assisted high aspect ratio plasma etching of silicon substrates capable of producing nanowires and microstructures. The deep vertical etching process consists of sequential oxygen-passivation and SF₆-etching of silicon at a record low density plasma of 0.25-0.5W/cm² (150-300W over an area of 20X30 cm²). A concurrent hydrogenation has been used to stimulate the vertical removal of the silicon substrate without damaging the sidewalls. These nanowires are being used for the fabrication of ultra-small vertical MOSFET transistors provided a sequential doping and etching is used to form the source and drain regions and the gate channel.