Conditions for Fabrication of Highly Conductive Wires by Electron-Beam-Induced Deposition

Conductive wires were fabricated by electron-beam-induced deposition (EBID) using WF 6 gas. It was difficult to fabricate highly conductive wires with good reproducibility unless samples were cleaned before EBID. Contamination appears to reduce the conductivity of the wires. O 2 plasma cleaning of samples before EBID seems to reduce contamination growth; however, it is not effective for regions in the vicinity of Au patterns. We found that by combining annealing at 300°C and O 2 plasma cleaning, highly conductive wires could be fabricated with relatively good reproducibility in such regions. A linear relation was found between wire conductance and linedose at lindoses of more than 70 µC/cm. The change in deposition yield estimated from the conductance was about 12% when the gas flux was halved. Wires with a length of less than 40 nm were less conductive than longer wires because of a shortage in gas supply.