Developing a Synthesis Process for Large-Scale h-BN Nanosheets Using Magnetron Sputtering and Heat Annealing

Hexagonal boron nitride (h-BN) is an extensively investigated 2D material with exceptional quantum effects, which renders it promising for use in next-generation nanoelectronic devices. However, the synthesis of single- or few-layer h-BN nanosheets with large-area single-crystal structures is extremely challenging. In this article, a new method is presented for synthesizing h-BN on a Cu substrate via magnetron sputtering and heat annealing. Three samples with different radio-frequency (RF) power levels are prepared to evaluate the effect of RF power on h-BN nanosheet synthesis. Under a higher RF power, the B-to-N bonding ratio is closer to 1:1 and further reduces the full width at half maximum of X-Ray photoelectron spectroscopy B1s and N1s narrow spectra. Heating at 1000 degrees C reveals white domains with 60 degrees facets, which may correspond to the hexagonal honeycomb lattice structure of h-BN. Cross-sectional observations show that a layered structure comprising 10-20 layers forms along the Cu interface. The elemental composition ratio and bonding states reveal the presence of equal amounts of N and B as well as a single peak derived from the B-N bond. Meanwhile, the E2g mode of h-BN's six-membered ring structure is indicated at 1364.6 cm-1, thus demonstrating the successful synthesis of an h-BN film. In this study, a new method is presented for synthesizing hexagonal boron nitride (h-BN) on a Cu substrate using magnetron sputtering and heat annealing in a vacuum environment. The structure and thickness of h-BN films can be controlled by appropriately adjusting the radio-frequency power, temperature, and synthesis time in the combination of sputtering and annealing processes.image (c) 2023 WILEY-VCH GmbH