Modelling and design of planar Hall effect bridge sensors for low-frequency applications
Modelling and design of planar Hall effect bridge sensors for low-frequency applications
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DOI：
10.1016/j.sna.2012.10.037
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发表时间：
2013-01
影响因子：
4.6
通讯作者：
A. Persson;R. Bejhed;F. W. Østerberg;K. Gunnarsson;Hugo Nguyen;G. Rizzi;M. F. Hansen;P. Svedlindh
中科院分区：
文献类型：
--
作者：
A. Persson;R. Bejhed;F. W. Østerberg;K. Gunnarsson;Hugo Nguyen;G. Rizzi;M. F. Hansen;P. Svedlindh
由于其可集成性、低质量和潜在的低成本，小型化磁场传感器在磁场检测的几个领域的适用性正在被探索。在这方面，不同的薄膜技术，特别是那些采用磁电阻的，显示出巨大的潜力，与批量微纳米加工技术兼容。在低频磁场检测中，基于平面霍尔效应的传感器，特别是基于平面霍尔效应桥（PHEB）的传感器，由于其固有的低场线性度、有限的磁滞和适中的噪声系数，具有很好的应用前景。在这项工作中，研究了这种PHEB传感器在不同区域的适用性。构建了一个分析模型来估计任意PHEB传感器几何形状的性能，例如灵敏度和探测率。该模型在不考虑形状各向异性影响的理想情况下是有效的，并且还包含了一些近似。为了验证结果，将建模数据与实际pheb的测量结果进行了比较，发现对所研究几何形状的预测值在13%以内。随后，利用该模型建立了优化PHEB的设计流程，以满足对带宽、探测性、顺应电压和放大信噪比的特定要求。通过应用该设计流程，可以估算出PHEB的尺寸、灵敏度、电阻、偏置电流和功耗。该模型表明，pheb可以应用于科学领域的几个不同领域，包括卫星姿态测定和芯片实验室应用中的磁头检测，在这些应用中需要低至1pthz - 0.5at 1Hz的探测，甚至可能适用于科学空间任务和考古调查中的磁场测量，其中探测率必须小于100pTHz - 0.5at 1Hz。
The applicability of miniaturized magnetic field sensors is being explored in several areas of magnetic field detection due to their integratability, low mass, and potentially low cost. In this respect, different thin-film technologies, especially those employing magnetoresistance, show great potential, being compatible with batch micro- and nanofabrication techniques. For low-frequency magnetic field detection, sensors based on the planar Hall effect, especially planar Hall effect bridge (PHEB) sensors, show promising performance given their inherent low-field linearity, limited hysteresis and moderate noise figure. In this work, the applicability of such PHEB sensors to different areas is investigated. An analytical model is constructed to estimate the performance of an arbitrary PHEB sensor geometry in terms of, e.g., sensitivity and detectivity. The model is valid for an ideal case, e.g., disregarding shape anisotropy effects, and also incorporates some approximations. To validate the results, modelled data was compared to measurements on actual PHEBs and was found to predict the measured values within 13% for the investigated geometries. Subsequently, the model was used to establish a design process for optimizing a PHEB to a particular set of requirements on the bandwidth, detectivity, compliance voltage and amplified signal-to-noise ratio. By applying this design process, the size, sensitivity, resistance, bias current and power consumption of the PHEB can be estimated. The model indicates that PHEBs can be applicable to several different areas within science including satellite attitude determination and magnetic bead detection in lab-on-a-chip applications, where detectivities down towards 1nTHz−0.5at 1Hz are required, and maybe even magnetic field measurements in scientific space missions and archaeological surveying, where the detectivity has to be less than 100pTHz−0.5at 1Hz.