From synchrotron radiation to I-V measurements of GaAs schottky barrier formation

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

Research output: Contribution to journalArticle

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Abstract

Through the use of synchrotron radiation photoemission spectroscopy (PES) and related techniques, we have gained detailed knowledge of Fermi level pinning, interfacial chemistry and disruption of GaAs for coverages up to several monolayers (ML). A link has been made between these data and that in the thick layer regime (hundreds of ML), which characterizes practical Schottky diodes. PES results for thin layers deposited at room temperature (RT) and low temperatures of about 80 K (LT) as well as thick films deposited at RT and annealed to higher temperatures are considered. At LT where GaAs disruption is minimized for thin films, metal-induced gap states seem to dominate the Fermi level pinning process except where GaAs metal reactions are strong. For RT thin and thick films, the effects of defects must be considered, and the advanced unified defect model (AUDM) is applied. In the AUDM the key defects are identified as the AsGa (double donor with levels at 0.75 and 0.5 eV above the valence band maximum) and the GaAs antisite (double acceptor) with the AsGa normally dominating due to the excess As which characterizes LEC GaAs crystals. The literature is reviewed and a number of phenomena are explained in terms of this model including the Fermi level position on MBE grown GaAs observed by Svensson et al. and the anomolously high Schottky barrier height (SBH) of thick Ga on n-GaAs observed by several groups. By performing electrical, TEM, and chemical studies of thick diodes and by evaluating the changes upon thermal annealing of diodes it is found that the AUDM successfully predicts the increase or decrease of barrier height on annealing.

Original languageEnglish (US)
Pages (from-to)1-16
Number of pages16
JournalApplied Surface Science
Volume41-42
Issue numberC
DOIs
StatePublished - Nov 2 1989
Externally publishedYes

Fingerprint

Synchrotron radiation
synchrotron radiation
Defects
Fermi level
defects
Diodes
Photoelectron spectroscopy
Thick films
thick films
Monolayers
room temperature
photoelectric emission
Temperature
diodes
Annealing
Thin films
annealing
Metals
thin films
Valence bands

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Condensed Matter Physics

Cite this

From synchrotron radiation to I-V measurements of GaAs schottky barrier formation. / Spicer, W. E.; Cao, R.; Miyano, K.; Kendelewicz, T.; Lindau, I.; Weber, E.; Liliental-Weber, Z.; Newman, Nathan.

In: Applied Surface Science, Vol. 41-42, No. C, 02.11.1989, p. 1-16.

Research output: Contribution to journalArticle

Spicer, WE, Cao, R, Miyano, K, Kendelewicz, T, Lindau, I, Weber, E, Liliental-Weber, Z & Newman, N 1989, 'From synchrotron radiation to I-V measurements of GaAs schottky barrier formation', Applied Surface Science, vol. 41-42, no. C, pp. 1-16. https://doi.org/10.1016/0169-4332(89)90026-3
Spicer, W. E. ; Cao, R. ; Miyano, K. ; Kendelewicz, T. ; Lindau, I. ; Weber, E. ; Liliental-Weber, Z. ; Newman, Nathan. / From synchrotron radiation to I-V measurements of GaAs schottky barrier formation. In: Applied Surface Science. 1989 ; Vol. 41-42, No. C. pp. 1-16.
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