DocumentCode :
1764707
Title :
Cu–Cu Bond Quality Enhancement Through the Inclusion of a Hermetic Seal for 3-D IC
Author :
Lan Peng ; Lin Zhang ; Hong Yu Li ; Chuan Seng Tan
Author_Institution :
Nanyang Technol. Univ., Singapore, Singapore
Volume :
60
Issue :
4
fYear :
2013
fDate :
41365
Firstpage :
1444
Lastpage :
1450
Abstract :
In this paper, we investigate the formation of hermetic seal, electrical contact, and mechanical support simultaneously through Cu-Cu bonding. Two types of test vehicles are designed and fabricated using wafer-to-wafer Cu thermocompression bonding to characterize the hermeticity and electrical contact of the Cu-Cu bonds. Excellent helium-leak rate is found and it is 30× lower than the reject limit (5×10-8atm.cm3/sec) with the application of seal ring with a width of ≥20 μm. This result shows an outstanding bonding quality against harsh environment for hermetic encapsulation in a 3-D integration application. In addition, the electrical stability of Kelvin structure is greatly improved with the inclusion of the Cu-Cu seal. FIB analysis shows that the Cu-Cu bond surrounded by the Cu-Cu seal results in remarkable reduction in imperfections at the bonding interface. Finally, high-density Cu-Cu bonding structures exhibit advantageous stability with the protection of the hermetic seal. This promotes Cu-Cu bonding as a reliable option for wafer level 3-D integration.
Keywords :
electrical contacts; hermetic seals; three-dimensional integrated circuits; wafer bonding; 3D IC; 3D integration application; Cu-Cu; Kelvin structure; bond quality enhancement; electrical contact; electrical stability; hermetic encapsulation; hermetic seal formation; hermetic seal inclusion; hermeticity contact; high-density bonding structures; mechanical support; outstanding bonding quality; seal ring application; wafer level 3D integration; wafer-to-wafer thermocompression bonding; Bonding; Contact resistance; Hermetic seals; Kelvin; Structural rings; 3-D IC; Cu–Cu bonding; hermetic sealing; kelvin structure;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/TED.2013.2248368
Filename :
6482674
Link To Document :
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