Ni(111) Substrate Engineering for the Epitaxial Chemical Vapor Deposition Growth of Wrinkle-Free Multilayer Rhombohedral Boron Nitride Films

Here, we report on the low-pressure chemical vapor deposition synthesis of multilayer BN films on single crystalline Ni(111) films. We highlight the crucial role of substrate pretreatment to stabilize the Ni(111) thin film on YSZ/Si(111) prior to BN precursor exposure at high temperature. We show that an in situ double-step thermal process under primary vacuum allows us to obtain clean and flat nickel surfaces suitable for homogeneous BN growth. Scanning and transmission electron microscopies, Raman spectroscopy, and atomic force microscopy have been used to characterize statistically the BN film from the atomic to the millimeter scale. We show that we obtain a sp²-hybridized BN film with a rhombohedral ABC stacking sequence. The 3 nm-thick film is continuous at the millimeter scale, with a mean roughness of 0.9 nm and no wrinkles.