Self-assembled semiconductor nanowires on silicon and insulating substrates: Experimental behavior

Metal-catalyzed semiconductor nanowires offer the possibility of combining nano-electronic structures with conventional electronics. They are formed by exposing a catalyst nanoparticle to a semiconductor precursor gas under conditions where the gas does not normally react. A column of the semiconductor (ie, the nanowire) is formed with diameter similar to that of the catalyzing nanoparticle. The growth of the nanowire depends on the size of the catalyzing nanoparticle, as well as the growth conditions. This approach offers the possibility of fabricating nanoscale electronic and sensing devices without costly and slow fine-scale lithography. When the connections to both ends of the nanowire are made during growth, advantages are obtained by combining "bottom up" fabrication of nanostructures with "top down" formation of the connecting electrodes using only conventional optical lithography. Self-assembled nanowires and "nano-bridges" constructed by the methods described here may provide some of the vital building blocks needed to enable the emerging technologies of nano-electronics and nano-sensors.