INFLUENCE OF DEFECT PASSIVATION BY HYDROGEN ON THE SCHOTTKY-BARRIER HEIGHT OF GAAS AND INP CONTACTS

The change in barrier height caused by sputter metallization of contac ts on both GaAs and InP substrates, and using evaporated contacts as a reference, is investigated. It has been found that by annealing, the reference barrier height can be restored. A model is proposed, wherein sputter metallization leads to passivation of interfacial defects by hydrogen. Accordingly, the Fermi level pinning caused by these defects is removed and the barrier height changes and is determined by other mechanisms. Annealing produces a removal of hydrogen and reactivates t he amphoteric defects. Additional evidence is given for the assumption that sputter metallization leads to passivation, by hydrogen, of dopa nts and defects in the semiconductor.