Formation of self-aligned TiN/CoSi/sub 2/ bilayer from Co/Ti/Si and its applications in salicide, diffusion barrier and contact fill

Abstract

A self-aligned TiN/CoSi/sub 2/ structure was formed from Co/Ti/Si; this scheme is compatible with salicide technology. Low contact/diffusion resistances and good device characteristics were obtained using this method. In addition, the TiN overlayer can be used for the diffusion barrier in between Al and CoSi/sub 2/ and for dopant diffusion. The dopant diffusion barrier permits the use of in-situ n/sup +//p/sup +/ doped selective Si plugs for contact filling. The TiN also improves the temperature stability of the underlying CoSi/sub 2/ film.<>