US 12,268,026 B2
High aspect ratio contact structure with multiple metal stacks
Junli Wang, Slingerlands, NY (US); Brent A Anderson, Jericho, VT (US); Terence Hook, Jericho Center, VT (US); Indira Seshadri, Niskayuna, NY (US); Albert M. Young, Fishkill, NY (US); Stuart Sieg, Albany, NY (US); Su Chen Fan, Cohoes, NY (US); and Shogo Mochizuki, Mechanicville, NY (US)
Assigned to International Business Machines Corporation, Armonk, NY (US)
Filed by International Business Machines Corporation, Armonk, NY (US)
Filed on Mar. 29, 2022, as Appl. No. 17/657,006.
Prior Publication US 2023/0317802 A1, Oct. 5, 2023
Int. Cl. H10D 64/23 (2025.01); H10D 64/01 (2025.01)
CPC H10D 64/251 (2025.01) [H10D 64/01 (2025.01)] 20 Claims
OG exemplary drawing
 
1. A semiconductor structure, comprising:
a contact structure within a dielectric material, the contact structure including a top portion in a first contact trench, the first contact trench having a straight sidewall from a top to a bottom of the first contact trench, and a bottom portion in a second contact trench, the second contact trench being below the first contact trench and extended horizontally from the first contact trench, and the top portion of the contact structure including a tapering profile towards the bottom portion;
a first metal stack within the top portion of the contact structure;
a second metal stack within the bottom portion of the contact structure, the second metal stack filling the second contact trench from a bottom to a top of the second contact trench; and
an inner spacer surrounding the first metal stack from a top to a bottom of the first metal stack, wherein a maximum width of the bottom portion of the contact structure is greater than a minimum width of the top portion of the contact structure.