  We study the effect of depolarization field related with inhomogeneous
polarization distribution, strain and surface energy parameters on a domain
wall profile near the surface of a ferroelectric film within the framework of
Landau-Ginzburg-Devonshire phenomenology. Both inhomogeneous elastic stress and
positive surface energy lead to the wall broadening at electrically screened
surface. For ferroelectrics with weak piezoelectric coupling, the extrapolation
length that defines surface energy parameter, affects the wall broadening more
strongly than inhomogeneous elastic stress. Unexpectedly, the domain wall
profile follows a long-range power law when approaching the surface, while it
saturates exponentially in the bulk. In materials with high piezoelectric
coupling and negligibly small surface energy (i.e. high extrapolation length)
inhomogeneous elastic stress effect dominates.
