Micro-Tesla Offset in Thermally Stable AlGaN/GaN 2DEG Hall Plates Using Current Spinning
Micro-Tesla Offset in Thermally Stable AlGaN/GaN 2DEG Hall Plates Using Current Spinning
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DOI：
10.1109/lsens.2019.2898157
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发表时间：
2019-03-01
影响因子：
2.8
通讯作者：
Senesky, Debbie G.
中科院分区：
文献类型：
--
作者：
Dowling, Karen M.;Alpert, Hannah S.;Senesky, Debbie G.
本文介绍了使用 AlGaN/GaN 2-D 电子气 (2DEG) 的低偏移霍尔板的表征。使用四相电流旋转技术将传感器偏移电压降低至类似于 20 nV 范围内的值，这对应于在提供低电压 (0.25-1 V) 时类似于 3.4 +/- 2 mu T 的低残余偏移。这些偏移比之前报道的 GaN 霍尔板的值小 30 倍，与最先进的电流旋转硅 (Si) 霍尔板相当。此外，即使在 2V 的较高电源电压下，偏移也不会超过 10μT。电流旋转是通过继电器矩阵以 1Hz 的开关频率完成的，以减少偏移。该传感器还在 -100 摄氏度至 200 摄氏度的宽温度范围内表现出稳定的电流标度灵敏度，温度系数接近 100 ppm/摄氏度。该值比最先进的 Si 霍尔板至少好 3 倍。此外，该传感器的电压相关灵敏度（类似于 57 mV/V/T）与最先进的 Si 霍尔板类似。由于电流旋转可实现低偏移值，AlGaN/GaN 2DEG 霍尔板是高温环境下低场电流和磁传感的可行候选方案。
This article describes the characterization of a low-offset Hall plate using the AlGaN/GaN 2-D electron gas (2DEG). A four-phase current spinning technique was used to reduce the sensor offset voltage to values in the range of similar to 20 nV, which corresponds to a low residual offset of similar to 3.4 +/- 2 mu T when supplied with low voltages (0.25-1 V). These offsets are 30x smaller than the values previously reported for GaN Hall plates, and it is on par with state-of-the-art current-spun silicon (Si) Hall plates. In addition, the offset does not exceed 10 mu T even at a higher supply voltage of 2 V. Current spinning was done with a relay matrix at a switching frequency of 1 Hz to enable an offset reduction. The sensor also shows stable current-scaled sensitivity over a wide temperature range of -100 degrees C to 200 degrees C, with a temperature coefficient of similar to 100 ppm/degrees C. This value is at least 3x better than the state-of-the art Si Hall plates. Additionally, the sensor's voltage-related sensitivity (similar to 57 mV/V/T) is similar to that of the state-of-the-art Si Hall plates. Because of the low offset values enabled by current spinning, the AlGaN/GaN 2DEG Hall plates are viable candidates for low-field current and magnetic sensing in high-temperature environments.