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This content will become publicly available on January 12, 2019

Title: Detecting Fermi-level shifts by Auger electron spectroscopy in Si and GaAs

In this study, changes in surface Fermi-level of Si and GaAs, caused by doping and cleaning, are investigated by Auger electron spectroscopy. Based on the Auger voltage contrast, we compared the Auger transition peak energy but with higher accuracy by using a more accurate analyzer and an improved peak position determination method. For silicon, a peak shift as large as 0.46 eV was detected when comparing a cleaned p-type and n-type wafer, which corresponds rather well with the theoretical difference in Fermi-levels. If no cleaning was applied, the peak position did not differ significantly for both wafer types, indicating Fermi-level pinning in the band gap. For GaAs, peak shifts were detected after cleaning with HF and (NH 4) 2S-solutions in an inert atmosphere (N 2-gas). Although the (NH 4) 2S-cleaning in N 2 is very efficient in removing the oxygen from the surface, the observed Ga- and As-peak shifts are smaller than those obtained after the HF-cleaning. It is shown that the magnitude of the shift is related to the surface composition. After Si-deposition on the (NH 4) 2S-cleaned surface, the Fermi-level shifts back to a similar position as observed for an as-received wafer, indicating that this combination is notmore » successful in unpinning the Fermi-level of GaAs.« less
 [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [1] ;  [1]
  1. KU Leuven, Heverlee (Belgium)
  2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  3. IBM Research Zurich, Ruschlikon (Switzerland)
  4. KU Leuven, Heverlee (Belgium); IMEC vzw, Heverlee (Belgium)
Publication Date:
Report Number(s):
Journal ID: ISSN 0169-4332; PII: S0169433218300801
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Applied Surface Science
Additional Journal Information:
Journal Volume: 440; Journal ID: ISSN 0169-4332
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org:
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE; Auger electron spectroscopy; semiconductor surface; Fermi level shifts; surface cleaning
OSTI Identifier: