The authors demonstrate the fabrication of suspended nanowires and doubly clamped beams by using a focused ion beam implanted Ga etch mask followed by an inductively coupled plasma reactive ion etching of silicon. This method will demonstrate how a two-step, completely dry fabrication sequence can be tuned to generate nanomechanical structures on either silicon substrates or silicon on insulator (SOI). This method was used to generate lateral nanowires suspended between 2 mu m scaled structures with lengths up to 16 mu m and widths down to 40 nm on a silicon substrate. The authors also fabricate 10 mu m long doubly clamped beams on SOIs that are 20 nm thick and a minimum of 150 nm wide. In situ electrical measurements of the beams demonstrate a reduction of resistivity from > 37.5 Omega cm down to 0.25 Omega cm. Transmission electron microscopy for quantifying both surface roughness and crystallinity of the suspended nanowires was performed. Finally, a dose array for repeatable fabrication of a desired beam width was also experimentally determined. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3497013]