Morphological and electrical study of FIB deposited amorphous W nanowires

Morphological and electrical measurements were carried out on W nanowires deposited by focused ion beam (FIB) onto the microhotplate of a micropellistor device. The I-V characteristics showed that the deposited W alloy wires have ohmic behaviour. Temperature dependent resistance measurements were carried out in vacuum (in situ in the chamber of the FIB/FESEM) and ex situ in air and in streaming nitrogen in the temperature range of 112-412 degrees C, using the micro-hotplate for temperature control. The first heat-up in vacuum caused a slight decrease of resistance followed by an irreversible, abrupt drop down to 3% of the as-deposited value, this value was kept during cool-down. The ex situ heat-up in air and N-2 atmosphere caused increasing resistance at temperatures over the range 300-350 degrees C, after a similar, slight decrease in the range of 200-300 degrees C, like in the case of vacuum ambient measurements. (c) 2007 Elsevier B.V. All rights reserved.