Employment of a bi-layer of Ni(P)/Cu as a diffusion barrier in a Cu/Sn/Cu bonding structure for three-dimensional interconnects
Employment of a bi-layer of Ni(P)/Cu as a diffusion barrier in a Cu/Sn/Cu bonding structure for three-dimensional interconnects
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DOI:
10.1016/j.actamat.2013.07.043
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发表时间:
2013-10
期刊:
影响因子:
9.4
通讯作者:
Byunghoon Lee;H. Jeon;Kee-Won Kwon;Hoo-Jeong Lee
中科院分区:
文献类型:
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作者:
Byunghoon Lee;H. Jeon;Kee-Won Kwon;Hoo-Jeong Lee
This study explored the possibility of employing a bi-layer barrier of electroless-plated Ni(P)/thin Cu layers in a Cu/Sn/Cu bonding structure for three-dimensional interconnects. Our materials analysis revealed that the bi-layer barrier served effectively as a diffusion barrier and prevented full-scale materials interaction for temperatures higher than 300 °C. Such suppression of an intermetallic compound reaction and limiting Cu diffusion led to the formation of a rod-shaped Cu6Sn5compound, rendering a unique microstructure of ductile Sn embedded with strong Cu6Sn5rods. Our mechanical characterization using lap-shear testing and fracture analysis revealed that the sample with such a microstructure displayed a high bonding strength with some ductility, a desirable combination for high mechanical reliability.