Method of simultaneous formation of salicide and local interconnects in

Abstract

A method of simultaneously forming refractory metal salicide and a local interconnect proceeds, after the standard formation of N+ and P+ junctions, by depositing titanium and TiN films and annealing the structure in nitrogen ambient to form a salicide film on the exposed source, drain and gate regions. A local interconnect mask is then employed to form local interconnect resist patterns. The TiN and unreacted titanium film are then etched off using a wet strip without attacking either salicide or field oxide. Following the etch, the salicide and local interconnect are again subjected to a rapid thermal anneal in a nitrogen ambient to reduce the sheet resistance of the salicide and the local interconnect and to convert the remaining titanium in the local interconnect into TiN film. The process flow can also be applied if cobalt is used instead of titanium and the cobalt is covered with a TiN cap.