Modeling and Measurement of CMOS-Based Three-Axis Magnetic Field Sensors With Low Cross-Sensitivity

This study investigates the modeling and measurement of a three-axis complementary metal-oxide–semiconductor (CMOS)-based magnetic field (MF) sensor chip. The sensor chip comprises three independent MF sensing components, namely, an x-axis MF (x-MF) sensor, a y-axis MF (y-MF) sensor, and a z-axis MF (z-MF) sensor, designed to detect MFs in the x-, y-, and z-directions, respectively. The design of separating the three sensors independently helps mitigate signal interference between them, significantly reducing their cross-sensitivity (CS). The behavior of the three-axis MF sensor is modeled using the Sentaurus TCAD semiconductor simulation software. The sensor chip is manufactured using a standard 0.18- $\mu $ m CMOS process without postprocessing. The experimental results indicate a sensitivity of 148 Mv/T for the x-MF sensor, 147 Mv/T for the y-MF sensor, and 19.2 Mv/T for the z-MF sensor. Moreover, the CS of the x-MF sensor, y-MF sensor, and z-MF sensor is all below 1%.