Investigation of the Band Alignment at h-BN/SiX Dielectric Interfaces utilizing X-ray Photoemission

Due to a wide band gap ($\sim $ 6 eV), close lattice matching (\textless 2{\%}) and atomic planarity, hexagonal boron nitride (h-BN) is of interest as a potential substrate and gate dielectric in graphene channel transistor devices. A key property for the success of h-BN as a gate dielectric in such devices is its interfacial band alignment with graphene, the gate contact metallization and the surrounding insulating dielectric materials. In this regard, we have utilized x-ray photoelectron spectroscopy (XPS) to determine the Schottky barrier and valence band offsets present at the interfaces between plasma enhanced chemically vapor deposited amorphous h-BN:H and a variety of materials including graphene, Cu, SiO$_{\mathrm{2}}$, a-SiN$_{\mathrm{x}}$:H, a-SiC:H, and Si. We show that in many instances the valence and conduction band offsets are significant ($\ge $ 2 eV) and favorable for a variety of possible h-BN/graphene transistor devices.