Epitaxial Growth of Copper Film by MOCVD

Abstract

Copper thin films were deposited on single crystal sapphire substrate via metal-organic MOCVD using Cu (acac)2 as precursor. X-ray diffraction (XRD) and Scanning Electronic Microscope (SEM) were employed for studying preferred orientation and microstructure. Atomic Force Microscope was utilized in order to characterize roughness of copper thin layer. By calculation of the Gibbs free energy, the reactions have been deeply understood. Depositions were carried out at various substrate temperatures in the rage 473K to 673K. It has been revealed that temperature determined the orientation and microstructure of copper films. At 673K, copper films have exhibited preferred orientation, smooth surface and connected grains, which proved that this copper thin film can act as precursor. Based on the study of epitaxial growth of copper films, a schematic diagram of epitaxial growth relationship is suggested for the step by step depositions processes.