Yasuyuki Kobayashi (1)*, Masanobu Hiroki (2), and Kazuhide Kumakura (2)

（1）Hirosaki University,  Bunkyo-cho, Hirosaki-shi, Aomori 036-8561, Japan

（2） NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198, Japan

*E-mail: kobayasu@hirosaki-u.ac.jp

 

Transfer of GaN-based heterostructures from one substrate to another is a fundamental challenge on the path toward future GaN-based electronic and optoelectronics applications. We grew GaN-based heterostructures (e.g., multiple-quantum-well (MQW) LED structures) on ultra-thin hexagonal BN (h-BN) layers with sapphire substrates using metalorganic vapor phase epitaxy (MOVPE) and demonstrated that they could be successfully released by mechanical force from the host sapphire substrates and transferred to other sapphire substrates [1]. The ultrathin h-BN layers work as not only buffer layers for the heteroepitaxial growth and but also release layers for the mechanical transfer. Electroluminescence intensities from the MQW LED transferred to the other sapphire substrate were higher than the intensities from an LED with the same MQW LED structure grown on the sapphire substrate without lift-off at the same current. The GaN-based heterostructures were also epitaxially grown on the ultrathin h-BN layers on sapphire substrates by molecular beam epitaxy (MBE). We clarified that the orientation relationship between the MOVPE-grown GaN and the substrates was the same as the one between the MBE-grown GaN and the substrates. These findings indicate that both MOVPE and MBE are promising technologies for the heteroepitaxial growth of both GaN-based heterostructures on the h-BN and the h-BN layers on the sapphire substrates. This work was supported in part by a Grant-in-Aid for Scientific Research (B) 18H01886 from the Japan Society for the Promotion of Science.

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[1] Y. Kobayashi et al., Nature 484 (2012) 223.