Interaction of atomic hydrogen, HS and H2S on GaAs(100)

Gaseous D-atoms are evidenced to react directly with adsorbed HS species, forming HD(g) and S remaining on the surface or HDS desorbing from the surface. On the other hand, exposing a D-covered GaAs(100) surface to H2S molecules causes a gradual decrease in the amount of adsorbed D-atoms and promotes the formation of HS(ad) without the observation of accompanying H(ad). The pure HS species covered surface generated by the coadsorption of H2S and D-atoms may lead to a more efficient S-passivation upon thermal annealing.