  A limited mobility nonequilibrium solid-on-solid dynamical model for kinetic
surface growth is introduced as a simple description for the morphological
evolution of a growing interface under random vapor deposition and surface
diffusion bias conditions. Simulations using a local coordination dependent
instantaneous relaxation of the deposited atoms produce complex surface mound
morphologies whose dynamical evolution is inconsistent with all the proposed
continuum surface growth equations. For any finite bias, mound coarsening is
found to be only an initial transient which vanishes asymptotically, with the
asymptotic growth exponent being 0.5 in both 1+1 and 2+1 dimensions. Possible
experimental implications of the proposed limited mobility nonequilibrium model
for real interface growth under a surface diffusion bias are critically
discussed.
