Fabrication and Feasibility of Through Silicon Via for 3D MEMS Resonator Integration

In this study, development of a wafer level, void free TSV fabrication process flow and feasibility study of TSV integration to MEMS piezoelectric resonator devices have been presented. TSV structures with 100 μm diameter and 350 μm depth were copper filled with via sealing and bottom-up electroplating process which is a two-step technique. Four-point Kelvin measurements showed 0.8 mΩ TSV resistance on fabricated TSVs. Furthermore, TSV frames were epoxy bonded to MEMS acoustic transducers, which showed 90% to the resonator signal from the TSV.