High-temperature three-dimensional GaN-based hall sensors for magnetic field detection

Abstract

Abstract Three-dimensional (3D) high-temperature Hall sensors are strongly required in various applications such as in the automotive and aircraft engines and in the diagnostic system of the thermonuclear reactors. In this paper, we propose a novel Hall sensor based on the wide-bandgap GaN-based materials on a single chip with greatly reduced area which can simultaneously detect 3D magnetic fields at high temperature up to 650 K. The device is analysed and demonstrated by performing the technology computer-aided design simulations, and significantly improved performances are achieved by employing space isolation and passivation scheme to effectively reduce the carrier interference from each dimension. Finally, high current-related magnetic sensitivities are found and the typical values are 128.6, 88.1, and 49.9 V A−1 T−1 on x, y and z axes, respectively, at room temperature. And the temperature coefficients are as low as −286.4, −366.8, and −202.9 ppm K−1, respectively. Moreover, dramatically improved cross-sensitivities are revealed and the maximum value is less than 1.0% at B ≤ 1.0 T which is much lower compared with other currently reported data. The work provides a new technical approach to realize a single-chip 3D magnetic sensor which is promising especially for high-temperature applications.