Demonstration of High-Performance GaN-Based Hall Sensors on Si Substrate by Simulation and Experiment Verification

Abstract

This work demonstrates high-performance wide bandgap GaN-based Hall sensors by theoretical simulation and experimental verification on 6-in wafer. Compared with the conventional fourfold rotationally symmetric cross-shaped structure, the twofold symmetric one has more flexible parameter selection and is able to exhibit better overall performances. The effects of different input and output aspect ratios on the device characteristics are investigated in detail. The simulation data show that the geometric factor and sensitivity of the devices are obviously improved with the increase of the aspect ratio of the input and output terminals, which is also demonstrated by the experimental results from the fabricated Hall sensors. The temperature drift coefficient is found to be less than 100 ppm/K in a wide temperature range of 300–675 K, and the minimum offset voltage is only 52 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{V}$ </tex-math></inline-formula> when the input current is kept at 1.0 mA. In addition, the angle- and noise-related characteristics of the devices are also investigated, and the root-mean-square voltage noise is determined to be <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.48~\mu \text{V}$ </tex-math></inline-formula> . Finally, the good uniformity of the 6-in wafer was verified. The low working noise and good temperature stability in a wide temperature range endow the fabricated GaN-based magnetic sensors with promising applications in harsh and high-temperature environments.