DocumentCode :
1053873
Title :
Gold–Aluminum Intermetallic Formation Kinetics
Author :
Blish, Richard C., II ; Li, Susan ; Kinoshita, Hiroyuki ; Morgan, Sheila ; Myers, Alline F.
Author_Institution :
Spansion Inc., Sunnyvale
Volume :
7
Issue :
1
fYear :
2007
fDate :
3/1/2007 12:00:00 AM
Firstpage :
51
Lastpage :
63
Abstract :
Au-Al intermetallic compounds (IMC) grow laterally (Al-rich phases) in a Fickian fashion with an activation energy of 1.0 eV, but vertical IMC thickness (Au-rich phases) grows functionally as a power law on time with a sub-Fickian exponent of 1/4, which is substantially smaller than what would be expected for bulk lattice diffusion (1/2). We conclude from the IMC thickness time exponent that an Au-rich IMC growth process is limited by grain boundary diffusion. The best bond lifetime was seen for an intermediate-thickness Al film. The activation energy and lifetime for Au-rich phase growth are each a strong function of wire impurity concentrations. We find that bond lifetime varies roughly as the square root of Pd, Cu, Pt, and As concentrations, but lifetime is not a function of Be, Ca, Fe, or Cr concentration. We find a mixture of and Au on the Al-rich side of the failing interface.
Keywords :
aluminium alloys; gold alloys; grain boundary diffusion; integrated circuit bonding; integrated circuit reliability; AuAl; Fickian fashion; activation energy; bond lifetime; bulk lattice diffusion; gold-aluminum intermetallic formation; grain boundary diffusion; growth process; Bonding; Chromium; Gold; Grain boundaries; Impurities; Intermetallic; Iron; Kinetic theory; Lattices; Wire; Integrated circuit bonding; integrated circuit packaging; integrated circuit reliability; life estimation; wire;
fLanguage :
English
Journal_Title :
Device and Materials Reliability, IEEE Transactions on
Publisher :
ieee
ISSN :
1530-4388
Type :
jour
DOI :
10.1109/TDMR.2007.891533
Filename :
4271481
Link To Document :
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