An investigation of the electrical properties of pyrolytic carbon in reduced dimensions: Vias and wires

Abstract

Nanoscale vertical interconnect structures (vias) made from chemical vapor deposited carbon have been investigated. The vias and wires were created by pyrolytic carbon deposition from acetylene at 950 °C followed by electron beam lithography and reactive ion etching. The carbon layer exhibits a resistivity of 4.5 mΩ cm in vias and wires which decreases to 1.5 mΩ cm after annealing at 1000 °C. The resistivity does not show any size effect in the vias, as it is independent of the diameter from 85 nm down to 24 nm. The maximum current density in long carbon wires was found to be 6×106 A cm−2, increasing to 3.5×108 A cm−2 for short vias.