Monolithic tri-axis cantilever high-shock accelerometers fabricated with a single-sided process in (111) wafers

Single-sided fabricated monolithic tri-axis piezoresistive high-shock accelerometers are reported in this paper. A single-cantilever structure and two dual-cantilever structures are designed and employed to detect the Z-axis and X-/Y-axis high-shock accelerations, respectively. Different longitudinal dimensions of the cantilevers can be achieved and well controlled with a (111) wafer single-sided process. The remained smooth backside facilitates simple post-packaging without chip bonding. The results of the high shock test show the sensitivity of X-/Y-axis and Z-axis is 0.80–0.85 μV/g and 1.36 μV/g, respectively. The proposed single-sided process is also promising to fabricate other complex structures with different longitudinal sizes.