Micro-Tesla Offset in Thermally Stable AlGaN/GaN 2DEG Hall-effect Plates using Current Spinning

This letter describes the characterization of a low-offset Hall-effect plate using the AlGaN/GaN two-dimensional electron gas(2DEG). Four-phase current spinning was used to reduce sensor offset voltage to values in the range of 20 nV, which corresponds to a low residual offset of 2.6 micro-Tesla whe...

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Bibliographic Details
Published in:arXiv.org 2018-12
Main Authors: Dowling, Karen M, Alpert, Hannah S, Ananth Saran Yalamarthy, Satterthwaite, Peter F, Kumar, Sai, Koeck, Helmut, Ausserlechner, Udo, Senesky, Debbie G
Format: Article
Language:English
Subjects:
Aluminum gallium nitrides
Electric potential
Electron gas
Hall effect
High temperature
Offsets
Phase current
Plates
Sensitivity
Sensors
Silicon
Space applications
State of the art
Thermal stability
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Summary:This letter describes the characterization of a low-offset Hall-effect plate using the AlGaN/GaN two-dimensional electron gas(2DEG). Four-phase current spinning was used to reduce sensor offset voltage to values in the range of 20 nV, which corresponds to a low residual offset of 2.6 micro-Tesla when supplied with low voltages (0.04 to 0.5V). These offsets are 50x smaller than the values previously reported for GaN Hall-effect plates, and it is on par with state-of-the-art silicon Hall-effect plates. In addition, the offset does not exceed 10 micro-Tesla even at higher supply voltage of 2.34V. The sensor also shows stable current-scaled sensitivity over a wide temperature range of -100C to 200C, with temperature drift of -125 ppm/C. This value is 3x better than state-of-the-art Silicon Hall-effect plates. Additionally, the sensor's voltage sensitivity (57 mV/V/T) is also similar. Because of their low offset values, AlGaN/GaN Hall-effect plates are viable candidates for low-field and high temperature magnetic sensing in monolithic GaN systems used in extreme temperature environments such as power inverter, down-well, combustion, and space applications.
ISSN:2331-8422