Selective photon-stimulated desorption of hydrogen from GaAs surfaces

Photon stimulated desorption of H+ from hydrogenated GaAs (110) and (100) s urfaces was studied as a function of photon energy. Distinct peaks, observe d around As 3d core-level binding energy for desorption from the GaAs (100) surface and in the As 3d and Ga 3p region for desorption from the GaAs (11 0) surface, show a striking similarity with the fine structure (spin-orbit splitting) measured in the photoemission from As 3d and Ga 3p levels. These results provide clear evidence for direct desorption processes and represe nt a basis for selective modification of hydrogenated GaAs surfaces.