AlGaN/GaN Micro-Hall Effect Devices for Simultaneous Current and Temperature Measurements From Line Currents

GaN/Al _0.20 Ga _0.80 N/GaN heterostructures were grown by molecular beam epitaxy and fabricated into micro-Hall effect sensors for the purpose of simultaneous current and temperature detection. The devices were characterized over a temperature range of -183 °C to 252 °C and were determined to be linearly dependent on magnetic field and temperature throughout. The high room temperature mobility of 2000 cm ² /Vs allowed for a very high magnetic field sensitivity of 113 VA ^-1 T ^-1 , which only decreased to 80 VA ^-1 T ^-1 at 252 °C. The ability to measure temperature while at the same time measure the magnitude of the B-field, and thus current in a nearby line is demonstrated. A method of decoupling temperature and current signatures is also shown together with a simple method of offset voltage understanding and removal.