Laser-induced sputtering of Ga0 and Ga+ from the GaP (110) surface: Its relation to surface imperfection

Abstract
We have measured emission of Ga+ ions and neutral Ga0 atoms induced by irradiation of the GaP (110) surface with laser pulses of subband‐gap energies. It is found that the Ga+ yield of partially annealed Ar+ ion bombarded surfaces is reduced by thermal annealing and also by repeated irradiation with laser pulses, while the Ga0 yield is not influenced to an important extent by these treatments. The Ga+ emission, which occurs at a lower fluence than Ga0 emission, is ascribed to emission from defect sites at surfaces. We suggest that measurements of laser‐induced particle emission for subband‐gap energies will be useful for detection and elimination of low‐density defects on surfaces.