ELECTRONIC-PROPERTIES OF GAAS(100) SURFACE PASSIVATED IN ALCOHOLIC SULFIDE SOLUTIONS

Using Raman spectroscopy and the Kelvin probe method the surface band bending and electron work function of GaAs(100) passivated in aqueous and alcoholic solutions of ammonium sulfide have been studied. It is s hown that the solvent strongly affects the position of energy levels o n the sulfide-treated surface. With the decrease of the solution diele ctric constant the surface band bending decreases and the electron wor k function increases both in n-GaAs and p-GaAs. The ionisation energy of the semiconductor increases after sulfur treatment and in n-GaAs it increases with the decrease of the dielectric constant of the solutio n. (C) 1998 Elsevier Science B.V. All rights reserved.