Initial Adsorption State for Al on GaAs(110) and Its Role in the Schottky Barrier Formation

Abstract

Synchrotron-radiation experiments were performed at ultralow (0.1 monolayer) coverages to test the weakly-interacting-cluster model for Al adsorption on GaAs(110). The evolution of the Al $2p$ peak revealed two different submonolayer adsorption states, one below and one above 0.1 monolayer coverage, as predicted by the model. These results demonstrate that experiments at ultralow coverages are crucial to the understanding of the Schottky barrier formation.