Galvanic Corrosion Between Copper and Tantalum under CMP Conditions

Chemical mechanical planarization (CMP) has emerged as the most viable method to planarize copper thin films during fabrication of integrated circuits. The final stage of copper CMP requires the simultaneous polishing of copper and the barrier metal, where the metals are prone to galvanic corrosion...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the Electrochemical Society 2006-01, Vol.153 (4), p.F53-F59
Main Authors: Tamilmani, Subramanian, Huang, Wayne, Raghavan, Srini
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Chemical mechanical planarization (CMP) has emerged as the most viable method to planarize copper thin films during fabrication of integrated circuits. The final stage of copper CMP requires the simultaneous polishing of copper and the barrier metal, where the metals are prone to galvanic corrosion due to exposure to slurry. In this study, the extent of galvanic corrosion between copper and tantalum was estimated using electrochemical polarization measurements. A novel setup was designed to make direct measurement of the galvanic current between copper and tantalum and was successfully used to measure galvanic current in two different chemical systems. Galvanic corrosion current values obtained from polarization and direct measurements are compared and their implications during barrier polishing are discussed.
ISSN:0013-4651
DOI:10.1149/1.2170583