通过具有BN插入层的范德华外延GaN实现高开/关电流比AlGaN/GaN HEMT

In nitride heteroepitaxy, lattice mismatch and thermal stress inevitably induce dislocation proliferation and defect formation, which critically degrade device reliability. In this letter, we demonstrate the high-quality epitaxial growth of nitride heterojunction structures on two-dimensional high-quality boron nitride (h-BN) materials via van der Waals epitaxy. Furthermore, BN also functions as a gate dielectric in the fabricated metal-insulator-semiconductor HEMT (MIS-HEMT), leveraging its ultrawide bandgap properties. The combined advantages of Buffer-assisted heterostructures and ultrawide-bandgap BN dielectric enabling a 10^3 -fold gate leakage reduction. Additionally, the proposed device exhibits an on/off current ratio of 10~^ {11} , with a maximum saturated output current density of 1550 mA/mm and 30% increase in transconductance. This shows the great potential of the proposed device for future power-electronics applications.