Structure and method for improved stabilization of cobalt cap and/or cobalt liner in interconnects
AssigneeInternational Business Machines Corporation
InventorsBenjamin D. Briggs, James J. Kelly, Koichi Motoyama, Roger Allan Quon, Michael Rizzolo, Theodorus Eduardus Standaert
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Abstract
A method of fabricating a metallization layer of a semiconductor device in which copper is used for an interconnect material and cobalt is used to encapsulate the copper. A material is introduced that will interact with the cobalt to cause a hexagonal-close-packed (HCP) crystal structure of cobalt to change to a face-centered-cubic (FCC) crystal structure of cobalt, the FCC crystal structure providing a resistance of the cobalt to migrate.
Claims20
A method, comprising, in a fabrication stage of a metallization layer of a semiconductor device in which copper is used for an interconnect material and cobalt is used to encapsulate said copper, introducing a material that will interact with said cobalt to cause a hexagonal-close-packed (HCP) crystal structure of cobalt to change to a face-centered-cubic (FCC) crystal structure of cobalt, said FCC crystal structure providing a resistance of said cobalt to migrate.
The method of claim 5, wherein said liner material comprises Ruthenium (Ru).
The method of claim 8, wherein said liner comprises ruthenium (Ru).
A method of inhibiting an electro-migration of copper (Cu) in copper interconnects in metallization layers of a chip, said copper interconnects encapsulated by a liner comprising cobalt (Co) and a cap comprising cobalt, said method comprising introducing a material that interacts with said cobalt to cause a hexagonal-close-packed (HCP) crystal structure of cobalt to change to a face-centered-cubic (FCC) crystal structure of cobalt, said FCC crystal structure providing a resistance of said cobalt to migrate.
A semiconductor chip, comprising:
- a substrate having a plurality of electronic component elements fabricated on a top surface thereof, in a device layer;
- and
- a plurality of metallization layers formed successively on top of said device layer, to interconnect said electronic component elements using copper (Cu), each said metallization layer having a different interconnect pattern,
- wherein said Cu in said Cu interconnect pattern in each said metallization layer is encapsulated in a layer of cobalt and wherein a material is introduced into an interconnect structure of said interconnect pattern of each said metallization layer that forms an alloy that interacts with said cobalt to cause a hexagonal-close-packed (HCP) crystal structure of cobalt to change to a face-centered-cubic (FCC) crystal structure of cobalt, said FCC crystal structure providing a resistance of said cobalt to migrate.
The semiconductor chip of claim 20, wherein said introduced material comprises at least one of nickel (Ni) and palladium (Pd).
A semiconductor chip, comprising:
- a substrate having a plurality of electronic component elements fabricated on a top surface thereof, in a device layer;
- and
- a plurality of metallization layers formed successively on top of said device layer, to interconnect said electronic component elements using copper (Cu), each said metallization layer having a different interconnect pattern,
- wherein said Cu in said Cu interconnect pattern in each said metallization layer is encapsulated in a layer of cobalt and wherein a material is introduced into an interconnect structure of at least one said interconnect pattern of at least one said metallization layer that interacts with said cobalt to cause a hexagonal-close-packed (HCP) crystal structure of cobalt to change to a face-centered-cubic (FCC) crystal structure of cobalt, said FCC crystal structure providing a resistance of said cobalt to migrate.
Dependencies are inferred from the claim text.