Van Der Waals Epitaxy h-BN/AlN Back Barrier with Controllable Boron-Diffusion for High-Erformance AlGaN/GaN HEMTs

We report a novel growth of nitride heterostructures directly on h-BN by MOCVD, achieving high-quality AlGaN/GaN HEMTs. By using aluminum ion implantation to pretreat the h-BN intermediate layer, creating a surface rich in unsaturated bonds as nucleation sites for highly oriented nitride growth. The 2 DEG concentration of h-BN/AlN back barrier AlGaN/GaN HEMT by van der Waals epitaxy reached <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$8.80 \times 10^{12} ~\text{cm}^{-2}$</tex> and the electron mobility was <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2091.3 ~\text{cm}^{2} / \mathrm{V} \cdot \mathrm{s}$</tex>, with a high On/Off ratio of 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup>.