Microelectronic magnetic sensors are essential in diverse applications, including automotive, industrial, and consumer electronics. Hall-effect devices hold the largest share of the magnetic sensor market, and they are particularly valued for their reliability, low cost and CMOS compatibility. This paper introduces a novel 3-axis Hall-effect sensor element based on an inverted pyramid structure, realized by leveraging MEMS micromachining and CMOS processing. The devices are manufactured by etching the pyramid openings with TMAH and implanting the sloped walls with n-dopants to define the active area. Through the use of various bias-sense detection modes, the device is able to detect both in-plane and out-of-plane magnetic fields within a single compact structure. In addition, the offset can be significantly reduced by one to three orders of magnitude by employing the current-spinning method. The device presented in this work demonstrated high in-plane and out-of-plane current- and voltage-related sensitivities ranging between 64.1 to 198 V A⁻¹ T⁻¹ and 14.8 to 21.4 mV V⁻¹ T⁻¹, with crosstalk below 4.7%. The sensor exhibits a thermal noise floor which corresponds to approximately \(0.5\,\mu \text{T}/\sqrt{\text{Hz}}\) at 1.31 V supply. This novel Hall-effect sensor represents a promising and simpler alternative to existing state-of-the-art 3-axis magnetic sensors, offering a viable solution for precise and reliable magnetic field sensing in various applications such as position feedback and power monitoring.

微电子磁传感器在各种应用中都是必不可少的，包括汽车、工业和消费电子产品。霍尔效应器件在磁传感器市场中占有最大的份额，其可靠性、低成本和 CMOS 兼容性尤其受到重视。本文介绍了一种基于倒金字塔结构的新型 3 轴霍尔效应传感器元件，该元件是通过利用 MEMS 微加工和 CMOS 加工实现的。这些器件是通过用 TMAH 蚀刻金字塔开口并在倾斜的墙壁上植入 n 掺杂剂来定义活动区域来制造的。通过使用各种偏置感应检测模式，该器件能够在单个紧凑的结构内检测面内和面外磁场。此外，采用电流旋转方法可以将偏移量显著减少 1 到 3 个数量级。这项工作中介绍的器件表现出较高的面内和面外电流和电压相关灵敏度，范围在 64.1 至 198 V ^{A-1 T-1} 和 14.8 至 21.4 mV ^{V-1 T-1} 之间，串扰低于 4.7%。该传感器的热本底热噪声约为 1.31 V 电源下约为 \（0.5\，\mu \text{T}/\sqrt{\text{Hz}}\）。这种新型霍尔效应传感器代表了现有最先进的 3 轴磁传感器的一种有前途且更简单的替代方案，为位置反馈和功率监控等各种应用中的精确可靠的磁场传感提供了可行的解决方案。