  Complex effect of different contributions (spontaneously formed In
nanoparticles, near-interface, surface and bulk layers) on electrophysical
properties of InN epitaxial films is studied. Transport parameters of the
surface layer are determined from the Shubnikov-de Haas oscillations measured
in undoped and Mg-doped InN films at magnetic fields up to 63 T. It is shown
that the In nanoparticles, near-interface and bulk layers play the dominant
role in the electrical conductivity of InN, while influence of the surface
layer is pronounced only in the compensated low-mobility InN:Mg films.
