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Eliminating Voids at Al 2 O 3 –Cu Interface During Direct Bonding
Author(s) -
Lee ShaoKuan,
Tuan WeiHsing
Publication year - 2014
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.12314
Subject(s) - materials science , eutectic system , copper , direct bonding , void (composites) , coating , oxygen , substrate (aquarium) , metallurgy , composite material , chemical engineering , microstructure , silicon , chemistry , oceanography , organic chemistry , engineering , geology
Direct bonding copper technique employs a eutectic liquid from C u– O system to bond copper to alumina. Many semispherical voids are found at the A l 2 O 3 – C u interface after bonding. Both the amount and the size of voids increase with the increase of oxygen content in copper. The void formation is resulted from the reduction of C u 2 O precipitates during bonding. Based on this observation, an approach to prevent the formation of voids is proposed. The approach introduces a sacrificial coating onto A l 2 O 3 substrate before bonding. The coating consumes the oxygen from the reduction, and the amount of voids is then reduced significantly.