Selective Doping of Silicon Nanowires by Means of Electron Beam Stimulated Oxide Etching

Direct patterning of silicon dioxide by means of electron beam stimulated etching is shown, and a full characterization of exposure dose is presented. For its high dose, this technique is unsuitable for large areas but can be usefully employed like a precision scalpel for removing silicon dioxide by well-localized points. In this work, this technique is applied to the definition of windows through the oxide surrounding top down fabricated n-doped silicon nanowires. These windows will be employed for a selective doping of the nanowire by boron diffusion. In this way, pn junctions can be fabricated in welllocalized points in the longitudinal direction of the nanowire, and an electrical contact to the different junctions can be provided. Electrical I-V characteristics of a nanowire with pn longitudinal junctions are reported and discussed.