High temperature scanning Hall probe microscopy using AlGaN∕GaN two dimensional electron gas micro-Hall probes

Abstract

Hall sensors fabricated using conventional narrow band gap semiconductors such as InSb and GaAs are unstable above room temperature due to the onset of intrinsic conduction and physical degradation of the semiconductor materials. Gallium nitride (GaN) based wide band gap semiconductors are stable at elevated temperatures and show potential for fabrication of high temperature electronic devices. Here, we incorporated high sensitivity AlGaN∕GaN two dimensional electron gas heterostructure micro-Hall probes (HPs) into a high temperature scanning Hall probe microscope and for magnetic imaging of domains in crystalline iron garnet thin films from room temperature to 100°C. The active area and Hall coefficient the HPs were 2×2μm2 and 0.01Ω∕G at 100°C, respectively. The evolution of the size of magnetic domains with increasing temperature under external magnetic fields is described.