XPS STUDIES OF IRRADIATED HARD AND SOFT Si—SiO2

The interracial structure of hard and soft oxides grown by dry oxidation on<100> n-type silicon substrates is examined using high resolution mild X-ray photoelectron spectroscopy (XPS) before and after irradiation. Substantial differences in silicon of silica state (B.E. 103.4 eV), silicon of transitional state (B.E. 101.5 eV), surplus oxygen (B.E. 529.6 eV) and negative two-valence oxygen (B.E. 531.4 eV) are observed between the two kinds of samples. The XPS spectra strongly depend on the conditions of irradiation for soft samples, but do not as remarkablely as soft samples for hard samples. The effects of irradiation doses on XPS are greater than that of irradiation bias fields. Some viewpoints of irradiation induced hole electron pair are proposed to explain the results.