A combined hall and stress sensor for highly accurate magnetic field sensing free from the piezo-Hall effect

This paper reports the use of a plate-like four-contact device for the simultaneous measurement of the magnetic field via the Hall effect and of the mechanical stress via the piezoresistance effect. The mechanical stress measurement is used to compensate for the piezo-Hall effect, i.e., the undesired cross-sensitivity of the magnetic sensitivity to mechanical stress. Thereby the drift of the magnetic sensitivity was reduced by a factor of 20 to 0.15% for mechanical stresses up to 75MPa and temperatures between 10°C and 60°C.