  We study the dispersion properties of surface plasmon oscillations in a
semi-bounded semiconductor plasma with the effects of the Coulomb exchange
force associated with the spin polarization of electrons and holes as well as
the effects of the Fermi degenerate pressure and the quantum Bohm potential.
Starting from a quantum hydrodynamic (QHD) model coupled to the Poisson
equation, we derive the general dispersion relation for surface plasma waves.
Previous results in this context are recovered. The dispersion properties of
the surface waves are analyzed in some particular cases of interest and the
relative influence of the quantum forces on these waves are also studied for a
nano-sized GaAs semiconductor plasma. It is found that the Coulomb exchange
effects significantly modify the behaviors of the surface plasmon waves. The
present results are applicable to understand the propagation characteristics of
surface waves in solid density plasmas.
