A Modified Damascene Electrodeposition Process for Bottom-up Filling of Recessed Surface Features

Published

July 23, 2010

Author(s)

Chang H. Lee, Thomas P. Moffat

Abstract

A modification of the conventional Damascene metallization process is described whereby selective removal of the thin wetting/seed layer from the sidewalls and free surfaces enables selective nucleation and bottom-up electrodeposition of metals and alloys in recessed surface features. The process is demonstrated by filling sub-micrometer trenches with electrodeposited Ni. A conventional PVD Cu seed layer is briefly etched to remove Cu from the sidewalls and free surface while leaving a continuous Cu wetting layer intact on the trench bottom. The underlying non-wetting barrier layer provides a conductive path for electrodeposition from contacts on the perimeter of the work piece. The robustness of the bottom-up Ni electrodeposition process is greatly increased by the addition of 2-mercaptobenzimidazole (MBI) to the plating bath. The additive prevents spurious nucleation of Ni on residual Cu patches that may remain on the free surface.

Citation

Electrochimica ACTA

Pub Type

Journals

Keywords

Bottom-up filling, Damascene process, nickel, mercaptobenzimidazole, superconformal deposition

Citation

Lee, C. and Moffat, T. (2010), A Modified Damascene Electrodeposition Process for Bottom-up Filling of Recessed Surface Features, Electrochimica ACTA (Accessed October 25, 2025)