Wafer-scale single-crystal hexagonal boron nitride monolayers on Cu (111)
Tac Chen1,2*
1R&D dept., Taiwan Elite Nano Technology Corp, Hsinchu, Taiwan
2Corporate Research, TSMC, Hsinchu, Taiwan
* Presenter:Tac Chen, email:anziex@gmail.com
Ultrathin two-dimensional (2D) semiconducting layered materials offer great potential for extending Moore’s law of the number of transistors in an integrated circuit. One key challenge with 2D semiconductors is to avoid the formation of charge scattering and trap sites from adjacent dielectrics. An insulating van der Waals layer of hexagonal boron nitride (hBN) provides an excellent interface dielectric, efferently reducing charge scattering. A reliable way of growing single-crystal hBN flms directly on wafers would contribute to the broad adoption of 2D layered materials in industry. Previous attempts to grow hBN monolayers on Cu (111) metals have failed to achieve mono-orientation, resulting in unwanted grain boundaries when the layers merge into films. Growing single-crystal hBN on such high symmetry surface planes as Cu (111) is widely believed to be impossible, even in theory. Nonetheless, here we report the successful epitaxial growth of single-crystal hBN monolayers on a Cu (111) thin film across a two-inch c-plane sapphire wafer. This surprising result is corroborated by our frst-principles calculations, suggesting that the epitaxial growth is enhanced by lateral docking of hBN to Cu (111) steps, ensuring the mono-orientation of hBN monolayers. This reliable approach to producing wafer-scale single-crystal hBN paves the way to future 2D electronics.

Keywords: 2D material, hexagonal boron nitride, Single-crystal , CVD