Thin Solid Films, Vol.461, No.2, 294-300, 2004
Deuterium post-metallization anneal of electrochemical-plated Cu film deposited on different barrier materials
In this paper, we report on electrochemical-plated (ECP) copper (Cu) film characterizations with different (Ta, TaN and TiN) barrier materials subjected to post-metallization-annealing (PMA) in deuterium (D-2) under various annealing conditions. For comparison, post-metallization-anneal of the ECP Cu film in pure nitrogen (N-2) and forming gas (20% hydrogen+80% nitrogen) were also performed. We used four-point probe to determine the sheet resistance. Scanning electron microscopy was used to examine the surface morphology of the after-annealed ECP Cu films. X-ray-diffraction (XRD) analysis was used to inspect the texture of the ECP Cu films before and after PMA. The deuterium distribution in the barrier layer was determined by using the secondary ion mass spectroscopy depth profile analysis. We found that under appropriate PMA conditions, the sheet resistance of ECP Cu films deposited on TaN barrier was the lowest after D-2 PMA when compared with those deposited on TiN and Ta barriers. (C) 2004 Elsevier B.V. All rights reserved.