  We report on the fabrication and electrical characterization of both single
layer graphene micron-sized devices and nanoribbons on a hexagonal boron
nitride substrate. We show that the micron-sized devices have significantly
higher mobility and lower disorder density compared to devices fabricated on
silicon dioxide substrate in agreement with previous findings. The transport
characteristics of the reactive-ion-etched graphene nanoribbons on hexagonal
boron nitride, however, appear to be very similar to those of ribbons on a
silicon dioxide substrate. We perform a detailed study in order to highlight
both similarities as well as differences. Our findings suggest that the edges
have an important influence on transport in reactive ion-etched graphene
nanodevices.
