Deposition of Cu and Ru Thin Films in Deep Nanotrenches/Holes Using Supercritical Carbon Dioxide

Supercritical CO 2 behaves like both a gas and a liquid, and posseses unique features such as nanopenetration capability, high diffusivity, and solvent ability. The technique described in this paper uses the supercritical CO 2 as a reaction medium for thin film growth and realizes filling or coating of nanofeatures with conducting metals. In this paper, we demonstrate the possibilities of this technique in Cu and Ru thin film deposition. A basic approach to achieving Cu metallization of deca-nanometer trenches or vias were studied. Ru, a promising material for capacitor electrodes and also a new candidate for the next-generation Cu barrier, was successfully deposited and its deposition characteristics were studied. Filling capability and the possibility of conformal deposition were also demonstrated as well as the fabrication of a Cu\Ru stack.