Evaluation and Optimization of Thermo-Mechanical Reliability of a TSV-Based 3D MEMS

This paper focuses on the thermo-mechanical reliability of a 3D-TSV MEMS in which cap layer and MEMS micro-structure layer is vertically interconnected and bonded by TSVs/micro-bumps and a sear ring. Geometrical parameters of the TSV structure and the seal ring are optimized first before the global model simulation. Smaller thickness of bottom TSV Cu and smaller opening size of silicon oxide layer are preferred in terms of thermo-mechanical reliability and electrical reliability. Quarter circular arc corner turning of radius 50µm decreases shear stress by at most 43.7% and peeling stress by at most 55.4% when compared with any other corner turning. In the end, the optimized structure parameters are introduced into the global model reliability simulation to verify the feasibility of the 3D-TSV MEMS.