Isotropic 3D silicon hall sensor

Abstract

This paper reports the first three-dimensional (3D) Hall sensor with isotropic sensitivity for the three spatial components of the magnetic field. The silicon device has the shape of a hexagonal prism with symmetric sets of three contacts on its top and bottom surfaces. Sending currents obliquely across the device allows one to operate it as three mutually crossing, identical, and effectively orthogonal Hall sensors. The sensitivity vectors of these Hall sensors are easily converted into sensitivities in the Cartesian coordinate system xyz. We demonstrate a design achieving sensitivities of S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> = 33.0 mV/VT, S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</sub> = 33.9 mV/VT and S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z</sub> = 33.3 mV/VT.