  We present experimental and modeling studies of UV nanosecond pulsed laser
desorption and ablation of (111) bulk silicon. The results involve a new
approach to the analysis of plume formation dynamics under high-energy photon
irradiation of the semiconductor surface. Non-thermal, photo-induced desorption
has been observed at low laser fluence, well below the melting threshold. Under
ablation conditions, the non-thermal ions have also a high concentration. The
origin of these ions is discussed on the basis of electronic excitation of Si
surface states associated with the Coulomb explosion mechanism. We present a
model describing dynamics of silicon target excitation, heating and
harge-carrier transport.

Materials Science;Chemical Physics