Liner-free tungsten contact

Abstract

An electrical structure comprises a dielectric layer present on a semiconductor substrate. A contact opening is present through the dielectric layer. A nickel-tungsten alloy silicide is formed over the semiconductor substrate within the contact opening. A tungsten-containing nucleation layer formed within the contact opening covers the nickel-tungsten alloy silicide and at least a portion of a sidewall of the contact opening. A tungsten contact is formed within the contact opening and separated from the nickel-tungsten alloy silicide and at least a portion of the sidewall by the tungsten-containing nucleation layer.

Dependencies are inferred from the claim text.