The use of selective silicide plugs for submicron contact fill

A novel contact fill scheme using a silicide plug has been developed. The scheme combines selective epitaxial Si growth (SEG) and silicide formation to form selective silicide contact plugs. Silicide plugs can be implemented in both n⁺ and p⁺ contacts with low contact resistance, high temperature stability, and good planarity. TEM and electrical measurements show that the above approach can be used to fill contact depth up to 1 μm and contact aspect ratio up to 1. The lack of a silicidation stop and the incomplete epi-Si consumption are two issues to be solved. For deeper contacts or contacts with higher aspect ratio, postsilicidation plug implantations become necessary to guarantee low contact resistances