Abstract
The advanced unified defect model (AUDM) is presented for GaAs interfaces with metals, other semiconductors, and insulators. The key defect is the AsGa anstisite, which is also responsible for EL-2 and semi-insulating GaAs. The energy levels of the AsGa antisite (0.75 and 0.52 eV) correspond well with the previously identified energy levels (0.75 and 0.5 eV) of the unified defect model (UDM). Using the AUDM, it is shown that a wide range of experimental data can now be explained. The Fermi level position on GaAs(001) MBE surfaces and its dependency on As or Ga are explained. The changes in Schottky barrier height of LaB6/GaAs, Al/GaAs, and Au/GaAS on annealing are explained in terms of AsGa antisite density near the interface being increased or decreased due to the annealing. For Al and Au this is correlated with the metal/semiconductor interfacial chemistry, and a predictive capability is developed in terms of net increase or decrease of As at the interface due to this reaction. The Fermi level pinning behavior at low temperature is also explained in terms of this model.
Original language | English (US) |
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Pages (from-to) | 1009-1029 |
Number of pages | 21 |
Journal | Applied Surface Science |
Volume | 33-34 |
Issue number | C |
DOIs | |
State | Published - Sep 1988 |
Externally published | Yes |
ASJC Scopus subject areas
- Chemistry(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films