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Grain growth and void formation in dielectric-encapsulated Cu thin films

Published online by Cambridge University Press:  31 January 2011

B. Yao
Affiliation:
Advanced Materials Processing and Analysis Center, University of Central Florida, Orlando, Florida 32826
T. Sun*
Affiliation:
Advanced Materials Processing and Analysis Center, University of Central Florida, Orlando, Florida 32826
V. Kumar
Affiliation:
Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
K. Barmak
Affiliation:
Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
K.R. Coffey
Affiliation:
Advanced Materials Processing and Analysis Center, University of Central Florida, Orlando, Florida 32826
*
a)Address all correspondence to this author. e-mail: ti857626@pegasus.cc.ucf.edu
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Abstract

Grain growth in 40-nm-thick Cu films encapsulated by over- and under-layers of SiO2, Al2O3, Si3N4, and MgO was investigated. The films were magnetron sputter deposited onto cooled SiO2/Si substrates in an ultrahigh vacuum purity environment. Ex situ annealing was performed at 400 and 800 °C in 1 atm reducing gas. Films deposited at −120 °C exhibited more extensive grain growth after annealing than films deposited at −40 °C. Films annealed at room temperature had grain sizes less than 35 nm. All films exhibited some void formation after annealing at 400 and 800 °C, but the films encapsulated in Al2O3 exhibited the lowest area fraction of voids. The mean grain sizes of the Al2O3-encapsulated films, as measured by the linear intercept method, were 86 and 134 nm after annealing at 400 and 800 °C, respectively.

Type
Articles
Copyright
Copyright © Materials Research Society 2008

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References

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