Highly Ordered Boron Nitride/Epigraphene Epitaxial Films on Silicon Carbide by Lateral Epitaxial Deposition

TL;DR

This paper reports on the epitaxial growth of highly ordered hexagonal boron nitride on epitaxial graphene on silicon carbide, using a lateral epitaxial deposition process that preserves graphene's transport properties for nanoelectronics.

Contribution

It introduces a migration-enhanced metalorganic vapor phase epitaxy method for growing multilayer h-BN on graphene, achieving highly ordered heterostructures with atomically sharp interfaces.

Findings

Epitaxial h-BN/EG heterostructures with highly ordered interfaces.

Growth mechanism involves one-dimensional nucleation-free-energy-barrierless process.

The process is applicable to various van der Waals materials.

Abstract

Realizing high-performance nanoelectronics requires control of materials at the nanoscale. Methods to produce high quality epitaxial graphene (EG) nanostructures on silicon carbide are known. The next step is to grow Van der Waals semiconductors on top of EG nanostructures. Hexagonal boron nitride (h-BN) is a wide bandgap semiconductor with a honeycomb lattice structure that matches that of graphene, making it ideally suited for graphene-based nanoelectronics. Here, we describe the preparation and characterization of multilayer h-BN grown epitaxially on EG using a migration-enhanced metalorganic vapor phase epitaxy process. As a result of the lateral epitaxial deposition (LED) mechanism, the grown h-BN/EG heterostructures have highly ordered epitaxial interfaces, as desired in order to preserve the transport properties of pristine graphene. Atomic scale structural and energetic details of the observed row-by-row, growth mechanism of the 2D epitaxial h-BN film are analyzed through first-principles simulations, demonstrating one-dimensional nucleation-free-energy-barrierless growth. This industrially relevant LED process can be applied to a wide variety of van der Waals materials.