Experimental characterization and modeling of the contact resistance of Cu-Cu bonded interconnects
Leong, H. L.
Gan, Chee Lip
Made, Riko I.
Thompson, Carl V.
Pey, Kin Leong
Li, H. Y.
Date of Issue2009
School of Materials Science and Engineering
The effects of the surface roughness and applied loads on the specific electrical contact resistance of three-dimensional Cu–Cu bonded interconnects have been quantitatively investigated. Wafer-level thermocompression bonding was carried out on bonded Cu layers with either different surface roughness at a certain load or with similar surface roughness at different applied loads. Experimental results show that as the surface roughness of the Cu bonding layer increases or as the bonding load decreases, the specific contact resistance of the bonded interconnects increases. A model is presented which quantifies the relationship between the specific contact resistance and the true contact area (which is a function of the surface roughness and applied load). Through the true contact area, the integrity of a bonded interface may be predicted from the electrical measurement of the contact resistance.
DRNTU::Engineering::Materials::Material testing and characterization
Journal of applied physics
© 2009 American Institute of Physics. This paper was published in Journal of Applied Physics and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at DOI: [http://link.aip.org.ezlibproxy1.ntu.edu.sg/link/doi/10.1063/1.3074503]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.