  The combination of h-BN and high-k dielectrics is required for a top gate
insulator in miniaturized graphene field-effect transistors because of the low
dielectric constant of h-BN. We investigated the deposition of Y2O3 on h-BN
using atomic layer deposition. The deposition of Y2O3 on h-BN was confirmed
without any buffer layer. An increase in the deposition temperature reduced the
surface coverage. The deposition mechanism could be explained by the
competition between the desorption and adsorption of the Y precursor on h-BN
due to the polarization. Although a full surface coverage was difficult to
achieve, the use of an oxidized metal seeding layer on h-BN resulted in a full
surface coverage.
