Temperature, Sensitivity, and Frequency Response of AlN/GaN Heterostructure Micro-Hall Effect Sensor
Satish Shetty, Savannah R. Eisner, Ayesha Hassan, Anand Vikas Lalwani, Dinesh Baral, Yuriy I. Mazur, Debbie G. Senesky, Hugh Churchill, Zhong Chen, Homer Alan Mantooth, Gregory J. Salamo · IEEE Transactions on Electron Devices · 2024
We report for the first time on an aluminum nitride/gallium nitride (AlN/GaN) heterostructure as a microscale Hall effect sensor for current sensing applications in extreme environments. The AlN/GaN devices demonstrated high signal linearity as a function of the magnetic field across a temperature range from$-$193$^{\circ}$C to 407$^{\circ}$C. The measured room temperature (RT) supply voltage-related sensitivity ($\textit{S}_{\text{svrs}}\text{)}$and supply current-related sensitivity ($\textit{S}_{\text{scrs}}\text{)}$are 0.055 T$^{-\text{1}}$and 32 VA$^{-\text{1}}$T$^{-\text{1}}$, respectively. The supply power-related sensitivity ($\textit{S}_{\text{sprs}}\text{)}$is 1.4 VW$^{-\text{1}}$T$^{-\text{1}}$above 40-mW input bias, which is higher than that of the Al$_{\text{0}.\text{2}}$Ga$_{\text{0}.\text{8}}$N/GaN device. The designed AlN/GaN micro-Hall sensor is further determined to have a lower power consumption and higher temperature sensitivity than equivalent Al$_{\text{0}.\text{2}}$Ga$_{\text{0}.\text{8}}$N/GaN Hall devices. When operated in an ac bias mode, the rise time of the Hall sensor was found to be 102 ns, corresponding to a frequency bandwidth of 9.8 MHz. We also observed a phase shift between an applied magnetic field and the Hall sensor signal, which can potentially be helpful to monitor ac line currents.