The advanced unified defect model and its applications

W. E. Spicer, T. Kendelewicz, N. Newman, R. Cao, C. McCants, K. Miyano, I. Lindau, Z. Liliental-Weber, E. R. Weber

Research output: Contribution to journalArticlepeer-review

57 Scopus citations


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 languageEnglish (US)
Pages (from-to)1009-1029
Number of pages21
JournalApplied Surface Science
Issue numberC
StatePublished - Sep 1988
Externally publishedYes

ASJC Scopus subject areas

  • General Chemistry
  • Condensed Matter Physics
  • General Physics and Astronomy
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films


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