Electrical characteristics of a novel interposer technique using ultra-low-resistivity silicon-pillars with polymer insulation as TSVs

In this paper, a novel silicon interposer technique using silicon pillars with ultra-low-resistivity as the conductor while polymer Benzocyclobutene (BCB) as liner layer is proposed. Fabrication flow of the proposed interposer structure is developed and implemented. Electrical performances, including transmißion performance and signal distortion characteristics, are investigated and presented using 3D full wave simulator and SPICE type circuit simulator such as ANSYS's HFß software and Agilent's ADS software, respectively. The impacts of geometric parameters and resistivity of silicon substrate on electrical characterizations are investigated in both frequency domain and time domain. Results show that the proposed interposer has comparable electrical performances such as return loß and insertion loß with conventional Cu-based through-silicon-via (TSV) structure in frequency region from 0.1 GHz to 10 GHz, despite of slight degradation at low frequency, but it involves a much simpler and more feasible proceß flow compared with the latter technique.