Fabrication and Characterization of InAs/AlSb based Magnetic Hall Sensors

Hall effect based magnetic field sensors are vector sensors which are sensitive to the perpendicular component of the magnetic field. Typically, Si-based Hall sensors are used for most usages requiring low field sensitivity. For higher sensitivity, III-V semiconductors such as GaAs, InSb, etc., provide better alternatives due to higher carrier mobilities at room temperature. In this work, Hall sensors based on two-dimensional electron gas (2DEG) at the heterostructure of InAs/AlSb are fabricated. The 2DEG is about 20 nm below the surface. Carrier density of
$3.2\times 1016/\mathrm{m}^{2}$
and mobility of 1.8 m
²
/Vs were deduced via Hall measurements at RT. 1/f-noise analyses were carried out to calculate the magnetic field resolution of
$\sim 1\ \mu\mathrm{T}/\text{Hz}^{1/2}$
. To demonstrate the application of Hall devices as magnetic field sensors, we also simulated the distortions in the geomagnetic field due to the presence of a ferromagnetic object. The magnetic field drops to about 10% (
$5 \mu\mathrm{T}$
) if we move 10cm away from the magnetic object. Our simulations show that the sensor fabricated in this work will be capable of detecting such distortions in the geomagnetic field from 10 cm.