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An XPS study of the initial stages of oxidation of hafnium
Author(s) -
Morant C.,
Galán L.,
Sanz J. M.
Publication year - 1990
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.740160163
Subject(s) - x ray photoelectron spectroscopy , hafnium , torr , saturation (graph theory) , chemisorption , oxide , crystallite , oxygen , analytical chemistry (journal) , chemistry , kinetics , materials science , inorganic chemistry , metallurgy , chemical engineering , crystallography , zirconium , adsorption , thermodynamics , environmental chemistry , physics , mathematics , organic chemistry , combinatorics , quantum mechanics , engineering
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 .