Demonstration of sputtered ScAlN/MOVPE-AlGaN/AlN/GaN HEMT

ScAlN is an attractive material as a barrier layer for high-frequency GaN high electron mobility transistors (HEMTs), owing to its wide-bandgap, strong polarization and ferroelectricity [1]. The regrowth of ScAlN on an $\mathrm{AlGaN} / \mathrm{GaN}$ HEMT structure provides process flexibility as well as new functionalities, such as enhancement and switching of the 2DEG. In this study, we demonstrate the regrowth of ScAlN using a sputtering method [2, 3] on AlGaN/AlN/GaN heterostructure, and fabricate and characterize ScAlN/AlGaN/AlN/GaN HEMTs.