Experimental and DFT study of boron nitride films grown on SiO2/Si substrates via chemical vapor deposition

Abstract

Boron nitride (BN), particularly the sp²-hybridized phase (sp²-BN), is an excellent two-dimensional (2D) insulating material that significantly enhances the performance of 2D electronic devices. Generally, the application of BN involves a transfer process, which results in the generation of certain impurities and defects. However, direct growth of BN on dielectric substrates can avoid these issues and contribute to further enhancing the performance of 2D electronic devices. In this study, high-quality sp²-BN film was directly grown on SiO₂/Si substrate by a chemical vapor deposition method with a “dissolution–diffusion” mechanism and “sacrificial metal Ni coating” methods, avoiding contamination issues that could arise during the transfer of BN. The growth of BN primarily relies on the diffusion at grain boundaries, which was confirmed by experiment and theoretical calculations. Moreover, graphene resistor devices were fabricated on this SiO₂/Si substrate with directly grown BN. This study indicated that the presence of BN can decrease the hysteresis phenomena of I–V curves, which is attributed to BN reducing the charge transfer and orbital hybridization between graphene and SiO₂. This study offers innovative insights and methodologies for the direct growth of high-quality BN on SiO₂/Si substrates, facilitating the development of high-performance 2D electronic devices.