  A systematic study based on the self-consistent dynamical simulations is
presented for the spontaneous evolution of flat solid droplets (bumps), which
are driven by the surface drift diffusion induced by the capillary and mismatch
stresses, during the development of the Stranski-Krastanow island morphology on
a rigid substrate. The physico-mathematical model, which bases on the
irreversible thermodynamics treatment of surfaces and interfaces with
singularities (Ogurtani, T.O., J. Chem. Phys. 124, 144706, 2006) furnishes us
to have auto-control on the otherwise free-motion of the triple junction
contour line between the substrate and the droplet without presuming any
equilibrium dihedral contract (wetting) angles at the edges. During the
development of Stranski-Krastanow islands through the mass accumulation at the
central region of the droplet via surface drift-diffusion with and/or without
growth, the formation of an extremely thin wetting layer is observed. . This
wetting layer has a thickness of a fraction of a nanometer and covers not only
the initial computation domain but also its further extension beyond the
original boundaries. Above a certain threshold level of the mismatch strain
and/or the size (i.e. volume) of the droplets, which depends on the initial
physicochemical data and the aspect ratio (i.e., shape) of the original
droplet, the formation of the multiple islands separated by the shallow wetting
layers is also observed
