Large scale epitaxy of AlGaN/GaN heterojunction films on h-BN/4H-SiC templates

In this study, large scale and high-quality AlGaN/GaN heterojunction films epitaxial grown on two-dimensional h-BN grown through metal–organic chemical vapor deposition were prepared on 6-inch 4H-SiC substrates. The crystal quality of GaN films were improved by adopting H₂/NH₃ etching at high temperature on h-BN surface before AlN nucleation layer deposition. Furthermore, GaN film grown on h-BN/4H-SiC template under 1200 ℃ pretreatment exhibited lower internal stress, which is one third of that grown on SiC substrate directly. Both h-BN grown on 6-inch 4H-SiC substrate and the subsequent epitaxial AlGaN/GaN heterojunction films have excellent uniformity.