Oct 14, 2019 | Metz, France
UMI researchers, led by Prof. Abdallah Ougazzaden, have demonstraded an innovative technology that can eliminate a costly step in the packaging of III-N optoelectronic devices. III-N devices typically require dicing of the epitaxial materials to separate individual devices from each other. In this new technique, a pattern of SiO2 was fabricated on the sapphire substrate. Then h-BN was grown on the wafer. The beauty of this this technique is the h-BN forms atomically flat layers on the exposed sapphire surface, while the h-BN on the SiO2 patterns was disordered. Then GaN-based device epitaxy was performed. Surprisingly, the h-BN on SiO2 did not permit subsequent growth of GaN-based materials, while the h-BN on Sapphire did permit growth of GaN-based devices. So the GaN based devices were physically separated from each other, and they could be easily removed from the substrate because h-BN is not chemically bonded to the GaN-based device. This technology has the possibility of eliminating dicing steps during III-N optoelectronic packaging by permitting convenient pick-and-place of individual devices on other substrates.