Highly Sensitive InGaAs-AlGaAs-GaAs 2DEG Quantum Well Hall Effect Integrated Circuits

GaAs-InGaAs-AlGaAs Hall sensor, current source, differential amplifier, comparator and source follower were integrated to form the first highly sensitive, low power (~18 mW) III-V DC unipolar Hall integrated circuit. This is a three terminal device which utilises 2 μm gate length technology, offering very high yields, at least ~50% higher switching sensitivity (~ 6 mT) compared to existing commercial unipolar ICs. In addition, the first low power (10.4 mW) and ultra-sensitive Linear Hall Effect Integrated Circuits (LHEIC) using the same GaAs-InGaAs-AlGaAs 2DEG technology have also been developed. These LHEIC have a state-of-the-art sensitivity of 533 μV/μT and are capable of detecting magnetic fields as low as 177 nT (in a 10 Hz bandwidth), at frequencies from 500 Hz to 200 kHz.