Copper-silicon carbide composite plating for inhibiting the extrusion of through silicon via (TSV)

• Published in: Microelectronic engineering Vol. 214; pp. 5 - 14
• Main Authors: Kee, Se-Ho, Kim, Won-Joong, Jung, Jae-Pil
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-06-2019; Elsevier BV
• Subjects: 3-D technology; Commercialization; Composite plating; Copper; Copper plating; Electronic packaging; Electroplating; Extreme values; Extrusion; High temperature; Integrated circuits; Interconnections; Packaging; Plating; Reliability; Silicon; Silicon carbide; Silicon wafers; Thermal expansion; Thermal expansion coefficient; Through-silicon-via; Packaging; Composite plating; Thermal expansion coefficient; Extrusion; Silicon carbide; Through-silicon-via
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2019.04.019

For 3D packaging using TSV technology, it is required various techniques such as forming via holes on a wafer, filling conductive materials and interpretation of TSV reliability etc. Among them, solving the issue of reliability are standing out as a big problem for reaching commercialization in the future. When the conductive material filled in the TSV is expanded by the high-temperature process during the packaging process, it breaks the insulating layer and the metal interconnection which exist on via hole by extruding from the surface of the Si wafer. In this study, in order to suppress the Cu extrusion, electroplating was attempted by adding silicon carbide powder having almost no difference in thermal expansion coefficient with the Si chip in the Cu electroplating solution. As a result, the extrusion height of Cu-SiC was about 164 nm that is a height corresponding to 14.6% of the extrusion height of Cu. This is considered to be the result of extremely effectively suppressing the extrusion phenomenon after annealing by adding SiC powder with a low coefficient of thermal expansion into the conventional Cu plating solution.
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•The current density abruptly increased when the contents of SDS is 100 ppm or more.•The hardness of the Cu-SiC plating layer was about 73% higher than that of the Cu.•The maximum Vickers hardness of TSV filled with Cu-SiC was 173.11 Hv.•The SiC powder was evenly located on the surface and the inside of TSV.•The extrusion of Cu-SiC seems to be suppressed by 84.5% compared to that of Cu.