Boron Nitride on Sapphire a Scalable and Versatile van der Waals Template for Growth and Lift-Off of Thin Films and Devices

Van der Waals surfaces, such as graphene or hBN, offer a unique route to growth, lift-off, and transfer of a wide variety of thin film materials and devices. Specifically, sp² bonded BN is interesting due to its atomically flat and smooth surface, high temperature and chemical stability, excellent insulating and dielectric properties, and ability to be grown uniformly over large areas 4” by commercial techniques such as metal organic chemical vapor deposition. Here we will describe the use of boron nitride on sapphire templates for growth of a variety of electronic films including GaN, AlN, AlScN, and Ga₂O₃, Key challenges, including nucleation, template morphology, stability, and strain will be covered with the goal of achieving high quality films that can be easily lifted off and transferred. Mechanical lift-off techniques including both soft and spalling induced methods for transfer of full wafers, individual devices, and selectively defined areas will be discussed. Finally, we will cover bonding these thin layers to a variety of surfaces in order to create heterojunctions and integrate devices.