Performances of AlGaN/GaN MIS-HEMT with Low-Temperature Sputtering-Deposited AlBN as Gate Dielectric and Passivation Layer

This work presents the development and optimization of low-temperature sputter-deposited AlBN as the gate dielectric and passivation layers for AlGaN/GaN MIS-HEMTs. AlBN, an aluminum nitride-based material, was selected due to its high dielectric constant, wide bandgap, and excellent compatibility with GaN, which can significantly improve device performance and reliability. We demonstrate the material processing and characterization of the sputtered AlBN layer, as well as the device performance analysis of AlBN-gated and passivated GaN MIS-HEMTs. The outstanding interface between the AlBN dielectric layer and the AlGaN barrier layer was revealed by high-resolution transmission electron microscopy. Electrical characterization demonstrates that the AlBN layer effectively reduces gate leakage and enhances the on-state drain current. A well-passivated surface for GaN MIS-HEMT devices was confirmed through dynamic on-state resistance measurements.