Physics of AlGaAs/InGaAs/GaAs heterostructures for high performance magnetic sensors

The interest of AlGaAs/InGaAs/GaAs heterostructures for the realization of Hall effect magnetic sensors with a high sensitivity and a low thermal drift has been investigated. The physical phenomena responsible for the thermal drift of the Hall sensitivity were reviewed and investigated using a set of test devices with well-controlled structure parameters. These results were used to optimize the structure design. A sensitivity of 900 V/A/T with a temperature coefficient of -160 ppm/°C was obtained.