A comparison of the effectiveness of GaAs surface passivation with sodium and ammonium sulfide solutions

To explore the possibility of improving the effectiveness of chemical and electronic passivation, a study has been made of the properties of GaAs surface treated with solutions of inorganic sulfides [Na2S and (NH4)(2)S] in various amphiprotic solvents (water, alcohols). X-ray photoelectron and photoluminescence spectroscopy shows that the efficiency of both chemical and of electronic passivation of GaAs surface increases with decreasing dielectric permittivity of the solvent. The degree of this increase reached with solutions of the sulfide of a strong base (Na2S) is larger than that of a weak-base sulfide [(NH4)(2)S]. (C) 1997 American Institute of Physics.