Abstract
We found that the Si 2p photoelectron peak binding energy of a Si substrate covered with a 3 nm thick HfAlO X film increased to a saturation value during X-ray irradiation. This shift towards a higher binding energy indicates an increase in the amount of positive charges in the film, and the density of hole traps is estimated to be significantly higher than that in a SiO 2 film. Before X-ray irradiation, the interface Fermi level coincided with the valence-band maximum of the Si substrate, which indicates that the Si surface band bends upward. This means that there were negative charges already in the film before X-ray irradiation. Investigating the effects of the interlayer beneath the HfAlO x film on these trapped charges reveals that the observed hole trapping and initial electron trapping are intrinsic to the HfAlO x film.
Original language | English |
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Pages (from-to) | 411-415 |
Number of pages | 5 |
Journal | Applied Surface Science |
Volume | 237 |
Issue number | 1-4 |
DOIs | |
Publication status | Published - 2004 Oct 15 |
Keywords
- Crystalline-amorphous interfaces
- Hafnium oxides
- Insulating films
- Semiconductorinsulator interfaces
- Silicon
- X-ray photoelectron spectroscopy
ASJC Scopus subject areas
- Chemistry(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films