Temperature Dependence on Structural, Tribological, and Electrical Properties of Sputtered Conductive Carbon Thin Films

Conductive carbon films were prepared at room temperature by unbalanced magnetron sputtering (UBMS) on silicon substrates using argon (Ar) gas, and the effects of post-annealing temperature on the structural, tribological, and electrical properties of carbon films were investigated. Films were annealed at temperatures ranging from 400 .deg. C to 700 .deg. C in increments of 100 .deg. C using a rapid thermal annealing method by vacuum furnace in vacuum ambient. The increase of annealing temperature contributed to the increase of the ordering and formation of aromatic rings in the carbon film. Consequently, with increasing annealing temperature the tribological properties of sputtered carbon films are deteriorated while the resistivity of carbon films significantly decreased from 4.5 x 10^-3 to 1.0 x 10^-6 Ω-cm and carrier concentration as well as mobility increased, respectively. This behavior can be explained by the increase of sp² bonding fraction and ordering sp² clusters in the carbon networks caused by increasing annealing temperature