Premium
X‐ray photoelectron spectroscopy of low‐temperature anodic silicon oxides
Author(s) -
Galán L.,
Montero I.,
Rueda F.,
Albella J. M.
Publication year - 1992
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.740190189
Subject(s) - x ray photoelectron spectroscopy , silicon , oxide , thermal oxidation , materials science , analytical chemistry (journal) , chemistry , chemical engineering , metallurgy , chromatography , engineering
Electron spectroscopy investigations of anodic silicon oxides grown over monocrystalline silicon and obtained at room temperature under different oxidation conditions are discussed and compared with thermal silicon oxide. In the first place, XPS shows that these oxides are essentially similar to thermal oxides with the same band gap, valence band spectra, plasma frequency, charge transfer and bulk mass density. However, there are also some important differences with respect to thermal oxides, related to the large density of structural defects, mainly OH and H 2 O, incorporated in the lattice during the growth process. In spite of the SiO 2 /Si interface appearing to be locally abrupt, this interface seems to be very rough. The anodic oxides have some oxygen excess and consequently the electronic polarizability of such materials is slightly smaller than that of thermal oxides. However, the most striking difference is the build‐up of a surface potential of 1.4–3.3 V upon x‐irradiation, even for thin, low‐resistivity anodic oxide films.