Condensation and cleaning of an organometallic copper compound to/from porous low-dielectric constant thin films in supercritical carbon dioxide

Porous low-dielectric-constant (low-k) thin films are demanded as insulating material for high-performance integrated circuits. One of the key technologies matching low-k processing is the use of supercritical carbon dioxide (scCO(2)) fluids. ScCO2 has a nano-penetration capability as well as solvent capability, which makes it a promising medium for the cleaning and: modification of low-k pores. However, few studies have been reported so far on in-situ ellipsometric measurement within supercritical fluids. We have developed an in-situ ellipsometry technique for use in scCO(2). In this article, the sorption behaviour of an organometallic compound, Cu(dibm)(2), on organosilica-based low-k thin films is reported as a model case of Cu contamination and the cleaning of low-k pores. Reversible adsorption/desorption behaviour was observed when the amount of Cu(dibm)(2) loaded was low, while less reversibility vas observed when a larger amount of Cu(dibm)(2), was used.