Motional Resistance Issue of TSV-Based Resonator Device and Its Improvement With a Concave Cu TSV Structural Design

Motional resistance of TSV-based resonator devices with 3D integration techniques is investigated at the operating oscillating mode. Even with well-developed TSV and device fabrication, the motional resistance issue of the TSV-based resonator device is found due to the poor connected Ag paste. The corresponding solution is demonstrated by a modified concave Cu TSVs structure. This modified concave Cu TSV design shows the excellent device characteristics and no visible gaps between the Cu TSVs and resonator devices to insure a good electrical connection.