  We present a new method of producing a densely ordered array of epitaxial
graphene nanoribbons (GNRs) using vicinal SiC surfaces as a template, which
consist of ordered pairs of (0001) terraces and nanofacets. Controlled
selective growth of graphene on approximately 10 nm wide of (0001) terraces
with 10 nm spatial intervals allows GNR formation. By selecting the vicinal
direction of SiC substrate, [1-100], well-ordered GNRs with predominantly
armchair edges are obtained. These structures, the high density GNRs, enable us
to observe the electronic structure at K-points by angle-resolved photoemission
spectroscopy, showing clear band-gap opening of at least 0.14 eV.
