Formation of CVD copper films investigated by surface analysis and reflectivity

Abstract
In this contribution we investigate the formation of copper films by chemical vapor deposition on silicon using the copper (II) bis(acetylacetonate) precursor. From Auger spectroscopy and ion sputtering, the chemical composition of the film is determined. We show that the carbon is on the CVD copper surface and plays an important role in stabilizing the silicon copper interface. The formation at 300°C of a metallic copper film on silicon instead of copper silicide is explained by the presence of carbon. The resistivity versus temperature has a behavior similar to the one observed on an evaporated copper film. Its value is for the best film two times higher than for pure copper. We present the evolution of the reflectivity of the film measured in situ during the MOCVD growth. Following the evolution of the reflectivity during the MOCVD process can give information on the nucleation process, the growth rate and the evolution of the roughness of the film.