We review the morphologic changes of Si(1 1 1)-(7 Γ 7) and InP(1 1 0)-(1 Γ 1) surfaces under repeated irradiation with laser pulses of intensities well below thresholds of melting and ablation. Direct imaging of the irradiated surfaces by means of scanning tunneling microscopy (STM) has revealed the excitation-induced electronic bond breaking, with efficiencies strongly site-dependent and highly superlinear with respect to the excitation intensity, resulting in formation of monovacancies and clustering of pre-existing vacancies. On Si(1 1 1)-(7 Γ 7), formation of monovacancies is predominantly induced under repeated irradiation, and the rate is constant up to the vacancy concentration of 10% relative to the total adatom sites. On the other hand, STM images of irradiated InP(1 1 0)-(1 Γ 1) have shown the preferential removal of the surface P atoms and prominent Fermi-level effects on the morphology of laser-induced vacancies: vacancy clusters are efficiently formed on n-type surface, while monovacancies are exclusively formed on p-type surface. The surfacedependent morphology of laser-induced vacancies can be explained by non-linear localization of surface holes at vacancy-sites based on the structural and electronic properties of the two surfaces.