Effects of NH 3 Plasma Treatment of the Substrate on Metal Organic Chemical Vapor Deposition of Copper Films

Surface modification by NH 3 plasma treatment enabled selective copper (Cu) chemical vapor deposition (CVD) and changed the structure of the deposited Cu film. After NH 3 plasma treatment of the substrate, Cu nucleation was suppressed on borophosphosilicate glass (BPSG), while Cu films were formed on TiN. NH 3 plasma treatment was not as effective as N 2 plasma treatment in inducing the selectivity. The lower efficiency of the NH 3 plasma in inducing the selectivity can be explained by the generation of NH ++ or H species. A Cu film deposited on plasma-treated TiN showed larger grains and enhanced (111) preferential orientation compared with that deposited on untreated TiN, which could be explained in terms of surface energy minimization.