Low-temperaturevan der waals epitaxy of GaN films on graphene through AlN buffer by plasma-assisted molecular beam epitaxy

Low-temperature growth of III-nitride semiconductor materials on non-single-crystalline substrates is necessary to realize inexpensive and large-area transferable GaN-films for flexible devices. In this work, the growth conditions and material properties of III-nitride films have been explored using plasmaassisted molecular beam epitaxy and AlN as a buffer layer. Migration enhanced epitaxy mode is the most suitable for the realization of low-temperature van der Waals epitaxy (vdWE). An AIN buffer layer with thickness of 10 nm grown by the MEE mode results in the optimizedcrystalline quality and surface flatness, which is extremely beneficial for the subsequentGaN film epitaxy. A single-crystalline GaN film with a flat surface has been obtained on AlN/graphene/quartz substrate at 530 degrees C, possessinga dislocation density about 1.10 x 10(11) cm(-2) and a RMS surface roughness of 2.04 nm for 10 x 10 mu m(2) area. The results obtained in this work can be applied to vdWE of III-nitrides on other 2D material/non-singlecrystalline substrates for their further applications in flexible devices or circuits. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study investigates the growth conditions and material properties of III-nitride films using plasma-assisted molecular beam epitaxy and AlN buffer layer, achieving low-temperature van der Waals epitaxy. The optimized crystalline quality and surface flatness of AlN buffer layer are beneficial for subsequent GaN film growth.