A Highly Sensitive 3-Axis Micro Search-Coil Magnetometer enabled by High-Density Through-Silicon-Via Process
- Resource Type
- Conference
- Authors
- Tavakkoli, Hadi; Duan, Mingzheng; Qi, Longheng; Izhar; Zhao, Xu; Lee, Yi-Kuen
- Source
- 2023 IEEE 36th International Conference on Micro Electro Mechanical Systems (MEMS) Micro Electro Mechanical Systems (MEMS), 2023 IEEE 36th International Conference on. :1095-1098 Jan, 2023
- Subject
- Bioengineering
Components, Circuits, Devices and Systems
Fields, Waves and Electromagnetics
Photonics and Electrooptics
Power, Energy and Industry Applications
Micromechanical devices
Fabrication
Sensitivity
Spirals
Three-dimensional displays
Magnetometers
Semiconductor device reliability
3-axis search-coil magnetometer
MEMS
planar spiral inductor
through silicon via (TSV)
- Language
- ISSN
- 2160-1968
We report a highly sensitive 3-axis micro search-coil magnetometer (μSCM) fabricated in one single silicon die and enabled by an in-house developed through-silicon-via (TSV) process. The z-axis μSCM is realized by two planar spiral inductors on both sides of the silicon wafer. The x & y-axis μSCMs are realized inside a silicon wafer by 400 TSVs (an array of 20×20 TSVs with a diameter of 50 μm) for each axis. A conformal polysilicon deposition is utilized to achieve an electrical connection through the etch holes inside the silicon wafer. Although partial filling of TSVs with polysilicon has higher resistance (< 3Ω per TSV) compared to complete filling, the proposed fabrication method is simpler and free of grinding and polishing steps, making it a more cost-effective alternative. The sensitivity (S) of the 3-axis μSCM (S x & S y = 134 mV/mT, S z = 3130 mV/mT at 100Hz) is better than existing μSCMs (13 mV/mT) by more than one order of magnitude.