International Business Machines Corporation

Kedari Matam

Cornelius Brown Peethala

Chih-Chao Yang

Theo Standaert

Daniel C Edelstein

Yann Mignot

Ashim Dutta

John Christopher Arnold

Devika Sil

A novel bevel etch sequence for embedded metal contamination removal from BEOL wafers is provided. In one aspect, a method of processing a wafer includes: performing a bevel dry etch to break up layers of contaminants with embedded metals which, post back-end-of line metallization, are deposited on a bevel of the wafer, which forms a damaged layer on surfaces of the wafer, and then performing a sequence of wet etches, following the bevel dry etch, to render the bevel of the wafer substantially free of contaminants, wherein the sequence of wet etches includes etching the damaged layer to undercut and lift-off any remaining contaminants. A wafer, processed in this manner, having a bevel that is substantially free of contaminants is also provided.

Embedded metal contamination removal from BEOL wafers

Techniques are provided to fabricate metal interconnects using liner planarization-free process flows. A sacrificial layer is formed on a dielectric layer, and the sacrificial and dielectric layers are patterned to form an opening in the dielectric layer. A conformal liner layer is deposited, and a metal layer deposited to form a metal interconnect in the opening. An overburden portion of the metal layer is planarized to expose an overburden portion of the liner layer. A first wet etch is performed to selectively remove the overburden portion of the liner layer. A second wet etch process is performed to selectively remove the sacrificial layer, resulting in extended portions of the liner layer and the metal interconnect extending above a surface of the dielectric layer. A dielectric capping layer is formed to cover the sidewall and upper surfaces of the extended portions of the liner layer and the metal interconnect.

Metallic interconnect structures with wrap around capping layers

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Albany, NY, United States of America

Kedari Matam