International Business Machines Corporation

Simon Gaudet

Christian Lavoie

Christophe Detavernier

Chih-Chao Yang

Shom Ponoth

Cyril Cabral, Jr

Terry Allen Spooner

Conal Eugene Murray

Roy Arthur Carruthers

Huiling Shang

Christophe Detavenier

A method for forming germano-silicide contacts atop a Ge-containing layer that is more resistant to etching than are conventional silicide contacts that are formed from a pure metal is provided. The method of the present invention includes first providing a structure which comprises a plurality of gate regions located atop a Ge-containing substrate having source/drain regions therein. After this step of the present invention, a Si-containing metal layer is formed atop the said Ge-containing substrate. In areas that are exposed, the Ge-containing substrate is in contact with the Si-containing metal layer. Annealing is then performed to form a germano-silicide compound in the regions in which the Si-containing metal layer and the Ge-containing substrate are in contact; and thereafter, any unreacted Si-containing metal layer is removed from the structure using a selective etch process. In some embodiments, an additional annealing step can follow the removal step. The method of the present invention provides a structure having a germano-silicide contact layer atop a Ge-containing substrate, wherein the germano-silicide contact layer contains more Si than the underlying Ge-containing substrate.

Self-aligned metal to form contacts to Ge containing substrates and structure formed thereby

An interconnect structure which includes a plating seed layer that has enhanced conductive material, preferably, Cu, diffusion properties is provided that eliminates the need for utilizing separate diffusion and seed layers. Specifically, the present invention provides an oxygen/nitrogen transition region within a plating seed layer for interconnect metal diffusion enhancement. The plating seed layer may include Ru, Ir or alloys thereof, and the interconnect conductive material may include Cu, Al, AlCu, W, Ag, Au and the like. Preferably, the interconnect conductive material is Cu or AlCu. In more specific terms, the present invention provides a single seeding layer which includes an oxygen/nitrogen transition region sandwiched between top and bottom seed regions. The presence of the oxygen/nitrogen transition region within the plating seed layer dramatically enhances the diffusion barrier resistance of the plating seed.

Plating seed layer including an oxygen/nitrogen transition region for barrier enhancement

The present invention provides a method for producing thin nickel (Ni) monosilicide or NiSi films (having a thickness on the order of about 30 nm or less), as contacts in CMOS devices wherein an amorphous Ni alloy silicide layer is formed during annealing which eliminates (i.e., completely by-passing) the formation of metal-rich silicide layers. By eliminating the formation of the metal-rich silicide layers, the resultant NiSi film formed has improved surface roughness as compared to a NiSi film formed from a metal-rich silicide phase. The method of the present invention also forms Ni monosilicide films without experiencing any dependence of the dopant type concentration within the Si-containing substrate that exists with the prior art NiSi films.

Eliminating metal-rich silicides using an amorphous Ni alloy silicide structure

An interconnect structure which includes a plating seed layer that has enhanced conductive material, preferably, Cu, diffusion properties is provided that eliminates the need for utilizing separate diffusion and seed layers. Specifically, the present invention provides an oxygen/nitrogen transition region within a plating seed layer for interconnect metal diffusion enhancement. The plating seed layer may include Ru, Ir or alloys thereof and the interconnect conductive material may include Cu, Al, AlCu, W, Ag, Au and the like. Preferably, the interconnect conductive material is Cu or AlCu. In more specific terms, the present invention provides a single seeding layer which includes an oxygen/nitrogen transition region sandwiched between top and bottom seed regions. The presence of the oxygen/nitrogen transition region within the plating seed layer dramatically enhances the diffusion barrier resistance of the plating seed.

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Montreal, Canada

Simon Gaudet