3D TSV based high frequency components for RF IC and RF MEMS applications

We demonstrate and review the unique fine-pitch high-aspect ratio tungsten-filled through-silicon vias (W-TSVs) technology developed by Fraunhofer EMFT in high-resitivity silicon substrates. The proposed process flow is fully compatible with both CMOS and MEMS technology, allowing 3D heterogeneous integration of highperformance, low power, compact tunable RF front-ends. We have assessed the figures of merit of the technology for RF functionality by fabricating and characterizing different configurations for CPWs with TSV transitions, mm-wave antennas and LC resonators as well as record-high performance wideband out-of-plane micro-inductors.