PRELUDE TO ETCHING - THE SURFACE INTERACTION OF CHLORINE ON GAAS(110)

The interaction of Cl2 with GaAs(110) was studied with photoelectron spectroscopy at 300 K. The results show that Cl2 dissociates and prefers Ga1+ bonding at low coverage and chemically distinct states can be correlated with structural information obtained from scanning tunneling microscopy. This Cl-Ga state was characterized by a distinct surface bonding configuration as Ga atoms lost charge, As atoms gained charge, and the surface bonds became less sp3-like. The result was a chemical shift for both Ga and As. Cl-Ga islands developed as the Cl coverage increased and subsequent adsorption of Cl within those islands enabled the formation of Cl-As bonds and an As1+ state.