METHOD OF FORMING A LOCAL INTERCONNECT

摘要

A local interconnect (LI) structure (112) is formed by forming a silicide layer (60, 50) in selected regions of a semiconductor structure then depositing an essentially uniform layer (110) of transition or refractory metal overlying the semiconductor structure. The metal local interconnect (112) is deposited without forming an intermediate insulating layer between the silicide (60, 50) and metal layers (110) to define contact openings or vias. In some embodiments, titanium is a suitable metal for formation of the local interconnect (112). Suitable selected regions (60) for silicide layer formation include, for example, silicided source/drain (S/D) regions and silicided gate contact regions (50). The silicided regions form uniform structures for electrical coupling to underlying doped regions that are parts of one or more semiconductor devices. In integrated circuits in which an etch-stop layer (100) is desired for the patterning of the metal film, a first optional insulating layer (100) is deposited prior to deposition of the metal film. In one example, the insulating layer is a silicon dioxide (oxide) layer that is typically less than 10 nm in thickness.