Semiconductor devices and methods to reduce contact resistivity in semiconductor devices

Abstract

Embodiments of semiconductor devices and methods are provided for reducing the resistivity of contact structures used in semiconductor devices. In the disclosed embodiments, an improved silicidation process is used to reduce the contact resistivity between an overlying metal plug and an underlying silicon-containing layer. The improved silicidation process reduces contact resistivity by forming a thin barrier metal silicide on an underlying silicon-containing layer before a thicker metal layer is deposited onto the barrier metal silicide and heated to form a second metal silicide above the barrier metal silicide. The combination of the barrier metal silicide and the second metal silicide provides a metal silicide-to-semiconductor contact between the overlying metal plug and the underlying silicon-containing layer with reduced contact resistivity.

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