Structures of and methods and tools for forming in-situ metallic/dielectric caps for interconnects
AssigneeInternational Business Machines Corporation
InventorsChih-Chao Yang, Chao-Kun Hu
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Abstract
A structure, tool and method for forming in-situ metallic/dielectric caps for interconnects. The method includes forming wire embedded in a dielectric layer on a semiconductor substrate, the wire comprising a copper core and an electrically conductive liner on sidewalls and a bottom of the copper core, a top surface of the wire coplanar with a top surface of the dielectric layer; forming a metal cap on an entire top surface of the copper core; without exposing the substrate to oxygen, forming a dielectric cap over the metal cap, any exposed portions of the liner, and the dielectric layer; and wherein the dielectric cap is an oxygen diffusion barrier and contains no oxygen atoms.
Claims26
A method comprising:
- (a) forming wire embedded in a dielectric layer on a semiconductor substrate, said wire comprising a copper core and an electrically conductive liner on sidewalls and a bottom of said copper core, a top surface of said copper core, a top surface of said electrically conductive liner and a top surface of said dielectric layer are coplanar;
- (b) forming a metal cap on an entire top surface of said copper core;
- (c) without exposing said substrate to oxygen, forming a dielectric cap on exposed surfaces of said metal cap, on all exposed surfaces of said liner, and on said top surface of said dielectric layer;
- and
- wherein said dielectric cap is an oxygen diffusion barrier and contains no oxygen atoms.
A structure, comprising:
- a wire embedded in a dielectric layer on a semiconductor substrate, said wire comprising a copper core and an electrically conductive liner on sidewalls and a bottom of said copper core, said copper core and said electrically conductive liner exposed at a top surface of said dielectric layer;
- a metal cap on an entire top surface of said copper core;
- a dielectric cap only over (i) said metal cap, (ii) any exposed portions of said liner, and (iii) on said top surface of said dielectric layer;
- and
- wherein an interface between said copper core and said metal layer does not contain oxygen.
Dependencies are inferred from the claim text.