Research of Transferable GaN Wafers Based on 2D Material-Assisted Growth for 6G Communication Devices

Two-dimensional (2D) material-assisted GaN growth is an advanced epitaxy technique that has recently emerged. This technique requires the insertion of a 2D material as an interlayer on a substrate, enabling epitaxy without direct bonding to the substrate. When growing GaN using 2D material assistance in a Metal-Organic Chemical Vapor Deposition (MOCVD) system, the interlayer can be damaged by substrate decomposition under harsh conditions such as high temperature and exposure to reactive gases. Due to the damaged interlayer, the grown membrane directly bonds to the substrate, leading to inseparable cases. Our results demonstrate strategies for achieving 2D material-assisted wafer-scale GaN growth using MOCVD. Hexagonal boron nitride (h-BN) was used as the interlayer. We grew GaN membranes under H2 or N2 carrier gas conditions and then conducted exfoliation tests. As a result, in the case of buffer layer growth at low temperatures, which adequately covered the 2D materials, separable 2D material-assisted GaN growth was achieved. Our results suggest that an appropriate low-temperature buffer layer is a key factor in 2D material-assisted GaN growth. This technology is expected to contribute to the production of more diverse 6G communication devices.