Exploring an Approach toward the Intrinsic Limits of GaN Electronics.

To fully exploit the advantages of GaN for electronic devices, a critical electric field that approaches its theoretical value (3 MV/cm) is desirable but has not yet been achieved. It is necessary to explore a new approach toward the intrinsic limits of GaN electronics from the perspective of epitaxial growth. By using a novel two-dimensional growth mode benefiting from our high-temperature AlN buffer technology, which is different from the classic two-step growth approach, our high-electron-mobility transistors (HEMTs) demonstrate an extremely high breakdown field of 2.5 MV/cm approaching the theoretical limit of GaN and an extremely low off-state buffer leakage of 1 nA/mm at a bias of up to 1000 V. Furthermore, our HEMTs also exhibit an excellent figure-of-merit (Vbr2/Ron,sp) of 5.13 × 108 V2/Ω·cm2.