We have already entered the post-Moore era and semiconductors today are reaching their operation limits. Semiconductor industry, in future, has to jump out of the original framework and seek new paths. New materials and processes like wide-bandgap semiconductors are emerging nowadays, and this trend will continue.
Researchers from the Chinese Academy of Sciences, Peking University and Beijing Graphene Institute (BGI) have recently realized the concept of “heterogeneous epitaxy” via a van der Walls strategy, a type of nonsymmetrical epitaxy process. The researchers confirmed that the feasibility of nitride epitaxy was not limited by the substrate lattice and provided a new idea for the heterogeneous integration of semiconductor materials.
The researchers used graphene to realize aligned nitride nucleation islands, which inherited crystallinity from the graphene lattice. Then the nitride nucleation islands absorbed adatoms (atoms that lie on a crystal surface) on the graphene surface and evolved into nanorods. Thus a smooth nitride film was formed.
Researchers said that graphene effectively guides the orientation of nitrides, while the designed nanorod template further narrows down the in-plane alignment to three dominant configurations.
“The in-plane dominant orientations are clearly exhibited by atomic resolution high-resolution transmission electron microscopy images at graphene boundaries, which is consistent with density functional theory calculation,” said Prof. Liu Zhiqiang, corresponding author of the research.
The research was published online in Science Advances.