Proton Irradiation Enhancement of Low-Field Negative Magnetoresistance Sensitivity of AlGaN/GaN-Based Magnetic Sensor at Cryogenic Temperature

The longitudinal and transverse magnetoresistances of AlGaN/GaN heterostructure-based micro-Hall sensors were compared with samples irradiated with protons with an energy of 380 keV and fluence of \(10^{14}\) (protons/cm \(^{2})\) . Increases in the elastic and inelastic scattering were deduced from weak localization behavior in both samples. The AlGaN/GaN micro-Hall sensors showed stable magnetic sensitivity in non and irradiated samples and increased resistivity after proton irradiation yielded an enhanced magnetoresistance sensitivity in nonirradiated sensors from 160 to 417 VA \(^{-1}\textrm {T}^{-1}\) . The minimum detectable magnetic field of irradiated micro-Hall sensors determined from magneto-voltage measurements at \(\sim 4\) K was similar to the minimum detectable magnetic field in the nonirradiated sensors.