  A strong disorder characterized by a small product of the Fermi vector kF and
the electron mean free l drives superconductors towards insulating state. Such
disorder can be introduced by making the films very thin. Here, we present 3-nm
Mo2N film with k_F*l ~ 2 with a resistive superconducting transition
temperature Tc = 2 K heavily suppressed in comparison with the bulk Tc.
Superconducting density of states (DOS) with smeared gap-like peaks and in-gap
states, so called Dynes DOS, is observed by the low temperature tunneling
spectroscopy despite a sharp resistive transition. By scanning tunneling
microscope the spectral maps are obtained and related to the surface
topography. The maps show a spatial variation of the superconducting energy gap
on the order of 20 % which is not accidental but well correlates with the
surface corrugation: protrusions reveal larger gap, smaller spectral smearing
and smaller in-gap states. In agreement with our previous measurements on
ultrathin MoC films we suggest that the film-substrate interface introducing
the local pair-breaking is responsible for the observed effects and generally
for the suppression of the superconductivity in these ultrathin films.
