A 3-D GaAs-based Hall sensor design with dual active layers structure

A fully integrated 3-D Hall magnetic sensor with dual active structure was proposed. Results by technology computer-aided design simulation show that the proposed sensor provides a doubled magnitude improvement in sensitivity of vertical magnetic field direction and maintains a good level sensing of horizontal magnetic field direction compared with the sensor with single active layer. The designed sensor was fabricated by wet etching process and a method of preparing Ohmic contacts on the "pseudo-sidewalls" is proposed. The measurements show that the non-linearity does not exceed 0.5% and a voltage sensitivity of up to 0.046 T-1, which matches the simulation results. The proposed sensor boasts a simplified structure that allows for fabrication using different layers only through a planar process, which makes it more conducive to the integration of devices and systems.