Initial oxidation process of ultrathin hafnium film on Si(111) surface studied by Hf 4f, Si 2p, and O 1s core-level spectroscopy

Abstract

In this study, the initial oxidation processes of ultrathin hafnium films on clean Si(111)-7×7 surface [Hf/Si(111)] were investigated by Hf 4f, Si 2p, and O 1s core-level photoelectron spectroscopy. As our results, Hf/Si(111) with a thickness of 2 ML including Hf monosilicide (HfSi) on surface shows low reactivity with O₂ molecules, while one of 6 ML including HfSi at interface and metallic Hf component on surface shows high reactivity with them.