Multilayer Graphene Growth via Sacrificial h-BN Segmentation

The patent divides the growth substrate surface into multiple regions by forming a sacrificial layer with spatially varying thickness. Different regions of the substrate receive different amounts of carbon atoms during CVD, enabling selective formation of 1, 2, 3, or more graphene layers in different areas. This segmentation approach transforms the uniform substrate into a multi-functional platform that can produce varying numbers of graphene layers simultaneously across large areas.

The sacrificial layer is formed in advance with a predetermined thickness distribution pattern before the CVD process. This preliminary structuring of the substrate surface with varying h-BN thicknesses (e.g., 1 nm in first region, 2 nm in second region, 3 nm in third region) pre-establishes the conditions for selective graphene layer formation, allowing the CVD process to directly produce the desired multilayer structure without complex in-situ control.

The patent applies local quality by creating a sacrificial layer with non-uniform thickness distribution across the substrate surface. Specific regions are assigned different h-BN thicknesses (1 nm, 2 nm, 3 nm, etc.) to locally control the number of graphene layers formed in each region. This local variation in substrate properties enables different parts of the large-area substrate to produce different numbers of graphene layers simultaneously, achieving both high quantity and large-area production.

The patent changes the physical parameter of the sacrificial layer thickness to control graphene layer formation. By varying the h-BN layer thickness from 1 nm to several nanometers across different regions, the available volume for carbon atom insertion is controlled, which directly determines the number of graphene layers that can be formed in each region during CVD. This parameter change approach provides a scalable method for producing multiple layers over large areas.