High-Aspect-Ratio Through Silicon Vias for High-Frequency Application Fabricated by Magnetic Assembly of Gold-Coated Nickel Wires

作者：Bleiker Simon J^*; Fischer Andreas C; Shah Umer; Somjit Nutapong; Haraldsson Tommy; Roxhed Niclas; Oberhammer Joachim; Stemme Goran; Niklaus Frank

来源：IEEE Transactions on Components, Packaging and Manufacturing Technology, 2015, 5(1): 21-27.

DOI：10.1109/TCPMT.2014.2369236

• RF signal transmission
• skin effect
• through silicon via (TSV)
• vertical interconnection
• wafer scale integration

In this paper, we demonstrate a novel manufacturing technology for high-aspect-ratio vertical interconnects for high-frequency applications. This novel approach is based on magnetic self-assembly of prefabricated nickel wires that are subsequently insulated with a thermosetting polymer. The high-frequency performance of the through silicon vias (TSVs) is enhanced by depositing a gold layer on the outer surface of the nickel wires and by reducing capacitive parasitics through a low-k polymer liner. As compared with conventional TSV designs, this novel concept offers a more compact design and a simpler, potentially more cost-effective manufacturing process. Moreover, this fabrication concept is very versatile and adaptable to many different applications, such as interposer, micro electromechanical systems, or millimeter wave applications. For evaluation purposes, coplanar waveguides with incorporated TSV interconnections were fabricated and characterized. The experimental results reveal a high bandwidth from dc to 86 GHz and an insertion loss of <0.53 dB per single TSV interconnection for frequencies up to 75 GHz.

• 出版日期2015-1