UWBG ferroelectric ScAlN/AlGaN high-electron mobility transistor

We report on the demonstration of ferroelectric ScAlN/AlGaN high-electron mobility transistors (HEMTs). The device exhibited a maximum drain density, ID, of ∼16 mA/mm with excellent electrostatic control at room temperature, demonstrating the integration of a molecular beam epitaxy-grown Sc0.15Al0.85N barrier with an Al0.50Ga0.50N channel, which was grown using metal-organic chemical vapor deposition. A counterclockwise hysteresis transfer curve was observed with a tunable threshold voltage range of 6.4 V, a high on/off current ratio (ION/IOFF) of ∼106, and a low subthreshold swing (SS) ∼65 mV/dec at drain voltage (VDS) = 1 V. The maximum ID was observed to increase with temperature up to 400 °C, suggesting thermally activated transport, driven by thermionic emission over the n+-GaN/Al0.50Ga0.50N heterobarrier. These results indicate that ferroelectric ScAlN/AlGaN HEMT is a promising candidate for the next-generation nonvolatile, reconfigurable power, and high-temperature memory applications.