Wideband capacitance evaluation of silicon-insulator-silicon through-silicon-vias for 3D integration applications

A novel silicon-insulator-silicon through-silicon-via (TSV) using ultra-low-resistivity silicon pillar as the conductor, while polymer benzocyclobutene as an insulation layer was successfully fabricated. With the help of on-wafer deembedding structure and vector network analyzer, wideband parasitic capacitance characteristics of a single TSV were accurately measured. Results show that stable capacitance over frequency (up to 50 GHz) and operation voltage (-20-20 V) is obtained with good wafer-level uniformity. Compared with the conventional Cu core TSV, the proposed structure not only exhibits a small and stable capacitance, but also involves a much simpler and cost-effective process flow.