On the formation of silicides on poly runners with topography by a two-step silicidation process

The formation of titanium and cobalt silicide on poly runners with topography is studied in this work. Poly runners with various topography heights and slopes were silicided by a two-step salicide process and inspected by SEM and electrical measurements. Even though the topography was more severe than in current PBLOCOS processes, no electrical defects in the continuity of the silicide were observed. Cross-section SEM reveals, however, that the metal coverage on the steps plays a major role in the continuity of the silicide formed.