A MEMS-SOI 3D-magnetic field sensor

A true-3D Hall sensor is reported which is fabricated based on MEMS micromachining of SOI-wafers which includes a flexible polyimide carrier so as to enable the development of a geometry-adaptable sensor when the three Hall-probes are positioned to form an orthogonally-oriented array on three faces of a non-magnetic material cube, yielding a true 3D-Hall sensor. Since the sensitivity of Hall-probes is defined by the doping level of the semiconductor material and the thickness of the Hall element, the sensitivity of each element is about the same (~100V/AT) when they are manufactured adjacent to each other on the silicon wafer where both, the doping level and the wafer thickness are near-identical.