Hybrid metal interconnects with a bamboo grain microstructure
AssigneeInternational Business Machines Corporation
InventorsBenjamin D. Briggs, Lawrence A. Clevenger, Michael Rizzolo, Chih-Chao Yang
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Abstract
A method of forming an interconnect with a bamboo grain microstructure. The method includes forming a conductive filler layer in a trench of an insulating layer to a predetermined depth such that an aspect ratio of a top portion of the trench is reduced to a threshold level, depositing a metal layer over the conductive filler layer in the top portion of the trench, the metal layer having a plurality of small grains, and annealing the metal layer to provide a bamboo grain microstructure having larger grains than grain boundaries of the plurality of small grains.
Claims14
A method for forming an interconnect with a bamboo grain microstructure, comprising:
- forming a conductive filler layer in a bottom portion of a trench of an insulating layer to a predetermined depth such that an aspect ratio of a top portion of the trench is reduced from an initial aspect ratio, the predetermined depth being less than a full depth of the trench;
- depositing a metal layer in the top portion of the trench over the conductive filler layer, the metal layer having a plurality of small grains;
- and
- annealing the metal layer to provide a bamboo grain microstructure having larger grains than grain boundaries of the plurality of small grains.
A method for forming an interconnect with a bamboo grain microstructure, comprising:
- depositing at least one conformal layer in a trench of an insulating layer such that the at least one conformal layer protects the insulating layer;
- forming conductive filler layer in a bottom portion of the trench to a predetermined depth such that an aspect ratio of a top portion of the trench is reduced from an initial aspect ratio, the aspect ratio being approximately 1:1 or less, wherein the predetermined depth is less than a full depth of the trench;
- depositing a metal layer in the top portion of the trench over the conductive filler layer, the metal layer having a plurality of small grains;
- and
- annealing the metal layer to provide a bamboo grain microstructure having larger grains than grain boundaries of the plurality small grains.
Dependencies are inferred from the claim text.