Fabrication of Self-Aligned Sub-100 nm Iron Wires by Selective Chemical Vapor Deposition

We have demonstrated the ability to fabricate and self-align sub-100 nm iron wires using a combination of silicon nitride spacer technology and selective deposition of iron and tungsten by chemical vapor deposition (CVD). The discovery of selective deposition of CVD iron, from pentacarbonyl [Fe(CO)5] precursor, on silicon nitride surfaces over tungsten surfaces is the key factor that allows the self-alignment of iron wires. The density and conductivity of the CVD iron layers improved as the deposition temperature increased. Deposition time of 1 min was sufficient to deposit a perfectly aligned, continuous iron wire. The deposited iron layer shows 100% selectivity.