標題: Comparison of oxidation in uni-directionally and randomly oriented Cu films for low temperature Cu-to-Cu direct bonding
作者: Tseng, Chih-Han
Tu, K. N.
Chen, Chih
材料科學與工程學系
國際半導體學院
Department of Materials Science and Engineering
International College of Semiconductor Technology
公開日期: 13-七月-2018
摘要: Cu-to-Cu direct bonding has attracted attention because it has been implemented in CMOS image sensors. Prior to the bonding, the oxides on the Cu surface needs to be removed, yet the surface may oxidize right after cleaning. Thus, oxidation is an inherent issue in the application of Cu direct bonding. Our previous study reported that Cu direct bonding can be achieved below 250 degrees C by using (111)-oriented nanotwinned Cu because it has the fastest surface diffusivity. However, the oxidation behavior of the nanotwinned Cu is unclear. Here, we examined the oxidation behavior of highly (111) and (200) oriented, and randomly-oriented Cu films at temperatures ranging from 120 to 250 degrees C. Transmission electron microscopy was used to measure the oxide thickness. The results show that the oxidation rate of (111)-oriented nanotwinned Cu has the lowest oxidation rate among them. Together, it is unique to possess the combination of the fastest surface diffusivity and the lowest oxidation rate.
URI: http://dx.doi.org/10.1038/s41598-018-28812-0
http://hdl.handle.net/11536/145254
ISSN: 2045-2322
DOI: 10.1038/s41598-018-28812-0
期刊: SCIENTIFIC REPORTS
Volume: 8
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