Anisotropic grain growth and anisotropic etching behavior of has been an active subject in the 2D materials research due to its importance in tuning property through controlling microstructure. Anisotropic growth is already a multi factor complicated process, while anisotropic etching would be more difficulty since the continuous 2D film formed through anisotropic or isotropic process would have different structure. It was reported before that hydrogen plays a dual role in the graphene and hBN growth process – it is required as a co-catalyst for dehydrogenization of hydrocarbon but also etches the growing crystal edges. A competition between the two defines not only the overall rate but the shapes of the individual domains. Analysis of hydrogen induced anisotropic etching can provide the necessary details and help to delineate the etching part from overall growth process.
Here we focusing on continuous anisotropic growth and etching process of hBN, and correlate the etching behavior with previous growth process.