An XPS study of the initial stages of oxidation of hafnium

✍ Scribed by C. Morant; L. Galán; J. M. Sanz

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 521 KB
• Volume: 16
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/sia.740160163

✦ Synopsis

Abstract

The oxidation kinetics of polycrystalline hafnium (Hf) at room temperature and low oxygen pressure (__P__o~2~ ∼ 10^−7^ Torr) has been studied by x‐ray photoelectron spectroscopy (XPS). After a chemisorption stage for exposures ⩽ 5 L, Hf suboxides are initially formed and are dominant until ∼ 25 L. HfO~2~ appears at ∼ 10 L. Above 25 L, HfO~2~ grows by oxidation of the suboxides, whereas the oxide film thickness remains constant. Above 500 L, a saturation region is observed that corresponds to an oxide layer of 12 Å thick with an average composition HfO~1.8~.