Improvement of morphological stability of Ag thin film on a TiN layer with a thin interposing metal layer

The morphological stability of Ag thin film on a TiN layer with a thin interposing metal layer has been investigated. Due to the formation of Ag spikes at the Ag/Si interface, a diffusion barrier is needed to buffer the interdiffusion of Ag with Si. TiN films deposited by physical vapor deposition (PVD) or metalorganic chemical vapor deposition (MOCVD) were used. A Au or Ti (similar to 3 nm) layer was used as the glue layer between Ag and TiN. In a Ag/Au/TiN system, a mixed Ag-Au layer is stable on PVD-TiN at temperatures as high as 450 degrees C. In Ag/Ti/TiN systems, the thermal stability of Ag on CVD-TiN is superior to that on PVD-TiN. Ag layers were found to be discontinuous after annealing at 300 and 350 degrees C on PVD-TiN and CVD-TIN systems, respectively. (C) 1999 American Vacuum Society. [S0734-2101(99)21304-8].