Surface of n-type InP (100) passivated in sulfide solutions

X-ray photoelectron spectroscopy, the Kelvin probe method, and Raman scattering are used to study the properties of the surface of n-type InP (100) passivated by ammonium sulfide dissolved in water or in t-butyl alcohol. Both treatments are found to cause a reduction in the depth of the depleted skin layer, a shift of the surface Fermi level toward the conduction band, and an enhancement of the electron work function and increase in the ionization energy of the semiconductor. The processing in the alcohol solution yields a stronger effect than processing in an aqueous solution. For sulfidization in an alcohol solution the surface Fermi level shifts by 0.2 eV, while the ionization energy increases by 0.53 eV. (C) 1999 American Institute of Physics. [S1063-7826(99)01104-7].