Government of the United States of America, As Represented by the Secretary of Commerce

Daniel Josell

Thomas P Moffat

Daniel Wheeler

A metallic grating is formed to include a substrate; a plurality of high aspect ratio trenches disposed in the substrate such that the high aspect ratio trenches are spaced apart from one another by a field surface of the substrate; a metallic superconformal filling formed and disposed in the high aspect ratio trenches; and a grating including a spatial arrangement of the high aspect ratio trenches that are filled with the metallic superconformal filling such that the metallic superconformal filling is void-free, and the high aspect ratio trenches are bottom-up filled with the metallic superconformal filling, wherein a height of the metallic superconformal filling is less than or equal to the height of the high aspect ratio trenches.

Process for making a metallic grating

A metallic grating includes a substrate; a plurality of high aspect ratio trenches disposed in the substrate such that the high aspect ratio trenches are spaced apart from one another by a field surface of the substrate; a metallic superconformal filling formed and disposed in the high aspect ratio trenches; and a grating including a spatial arrangement of the high aspect ratio trenches that are filled with the metallic superconformal filling such that the metallic superconformal filling is void-free, and the high aspect ratio trenches are bottom-up filled with the metallic superconformal filling, wherein a height of the metallic superconformal filling is less than or equal to the height of the high aspect ratio trenches.

Metallic grating

Superconformally filling a recessed feature includes: contacting the recessed feature with superconformal filling composition that includes: Au(SO)anions; SOanions; and Bications; convectively transporting Au(SO)and Bito the bottom member of the recessed feature; subjecting the recessed feature to an electrical current to superconformally deposit gold from the Au(SO)on the bottom member relative to the sidewall and the field, the electrical current providing a cathodic voltage; and increasing the electrical current subjected to the field and the recessed feature to maintain the cathodic voltage between &#x2212;0.85 V and &#x2212;1.00 V relative to the SSE during superconformally depositing gold on the substrate to superconformally fill the recessed feature of the article with gold as a superconformal filling of gold, the superconformal filling being void-free and seam-free.

Superconformal filling composition and superconformally filling a recessed feature of an article

Forming a transition zone terminated superconformal filling in a recess includes: providing an electrodeposition composition including: a metal electrolyte including a plurality of metal ions, solvent, and suppressor; providing the article including: a field surface and the recess that includes a distal position and a proximate position; exposing the recess to the electrodeposition composition; potentiodynamically controlling an electric potential of the recess with a potential wave form; bifurcating the recess into an active metal deposition region and a passive region; forming a transition zone; decreasing the electric potential of the recess by the potential wave form; progressively moving the transition zone closer to the field surface and away from the distal position; and reducing the metal ions and depositing the metal in the active metal deposition region and not in the passive region to form the transition zone terminated superconformal filling in the recess of the substrate.

Process for forming a transition zone terminated superconformal filling

The process of this invention involves first adsorbing a catalyst on the surface of a specimen by immersion in a catalyst-containing solution, followed by electrolytic deposition in a second solution that need not contain catalyst. This two-step superconformal process produces a seam-free and void-free metal microelectronic conductor.

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N. Potomac, MD, United States of America

Daniel Josell