Magnetron Sputtering Deposition of Conductive Diamond-Like Carbon Films with Embedded Nanoparticles

Abstract

We developed a process technology for synthesizing conductive diamond-like carbon (DLC) films, in which nanoparticles embedded in the DLC films played the role of the paths of electric current. The synthesis process consisted of three steps. The first step was the deposition of nanoparticles, which was realized by operating a magnetron sputtering source with pure argon at a pressure of 500 mTorr. The second step was the deposition of a DLC film, which was realized by operating the same magnetron sputtering source with the mixture of argon and hydrogen at a pressure of 5 mTorr. The third step was the removal of the residual DLC film on nanoparticles. This step was realized using a plasma with the mixture of argon and oxygen, which was produced by applying an rf power to the substrate holder of the same magnetron sputtering source. The conductivity of a DLC film with embedded copper nanoparticles was nearly high enough to be the surface coating of separators in polymer electrolyte fuel cells.