Analysis of Orthogonal Coupling Structure Based on Double Three-Contact Vertical Hall Device

Abstract

A vertical Hall device is an important component of 3D Hall sensors, used for detecting magnetic fields parallel to the sensor surface. The Hall devices described in existing research still have problems, such as large offset voltage and low sensitivity. Aiming to solve these problems, this study proposes a double three-contact vertical Hall device with low offset voltage, and a conformal mapping analysis method to improve the sensitivity of the device. Secondly, an orthogonal coupling structure composed of two sets of double three-contact vertical Hall devices is proposed, which further reduces the offset voltage of the device. Finally, the TCAD simulation software was used to analyze the performance of the devices, and an existing vertical Hall device was compared to ours. The results show that the orthogonal coupling structure in this study exhibits better performance, reaching an average voltage sensitivity of 17.5222 mV/VT and an average offset voltage of about 0.075 mV. In addition, the structure has the same magnitude of offset voltage in the four phases of the rotating current method. This characteristic enables the back-end circuit to more accurately filter out the offset voltage and acquire the Hall signal.

Design and Application of MEMS-Based Hall Sensor Array for Magnetic Field Mapping

“…Figure 2 presents a schematic illustration of the sensor proposed in the present study consisting of a 4-inch silicon wafer, a silicon dioxide insulating layer, metal leads, and a cross-shaped phosphide-doped detection zone [ 25 , 26 , 27 ] For comparison purposes, four devices are fabricated, in which the cross-shaped detection zones have the same aspect ratio (L/W = 2.625), but different sizes, namely S, M, L, and XL. In the proposed devices, the analog signals are amplified by a large-current operational amplifier (AD620) and then supplied to an analog-to-digital converter (MEGA2560).…”

Sensitivity Improvement of a Fully Symmetric Vertical Hall Device Fabricated in 0.18 μm Low-Voltage CMOS Technology

“…A vertical Hall plate structure with a high negative differential sensitivity is also put forward [19], applying novel signal extraction techniques for sensitivity enhancement. An orthogonal coupling structure composed of two sets of double three-contact vertical Hall devices has been proposed, which achieves the purpose of further reducing the offset voltage while maintaining the device sensitivity [20].…”