Passivation of a Si(100) surface by S from solution

A wet-chemical process has been developed to passivate the Si(100) surface with sulfur (S) in an aqueous solution. The solution contains an etchant for SiO2, ammonium hydroxide (NH4OH) and a passivant for the surface, ammonium sulfide [(NH4)(2)S]. The compatibility of the etchant with the passivant allows SiO2, native or thermal, to be removed in situ from the surface. A fresh and clean Si(100) surface is exposed right before it is passivated by S. Schottky barrier heights of Al on S- passivated n- and p-type Si(100) show a greater sensitivity to Al work function and Si electron affinity, suggesting good-quality passivation. (c) 2007 The Electrochemical Society.