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Title: The effects of the initial stages of native-oxide formation on the surface properties of GaSb (001)

Atomically clean surfaces of n-type GaSb (001) have been prepared by a combination of ex-situ wet-chemical treatment in HCl and in-situ annealing in a flux of H atoms in ultra-high vacuum (UHV). The surfaces are exposed to 'excited' O{sub 2} and studied using primarily x-ray photoelectron spectroscopy. Low O{sub 2} exposures, up to {approx}3 Multiplication-Sign 10{sup 3} Langmuirs (L), result in a partial passivation of electrically active defects as shown by a decrease in upward band bending. Adsorption of O{sub 2} in this exposure range appears to form mainly Ga{sup +1} sites, with little or no indication of Ga{sup +3}, and saturates at an O coverage of {approx}0.2-0.3 monolayers. For exposures of {approx}10{sup 4} L or higher, oxidation occurs through insertion into Ga-Sb bonds as indicated by the onset of Ga{sup +3} as well as of Sb{sup +4} and/or Sb{sup +5} together with the appearance of an O 1s feature. Defects resulting from this process cause a reversal of the band-bending change seen for smaller exposures. Data obtained for the composition of a native oxide formed in situ in UHV are compared with those for a 'practical' surface produced by processing under ambient conditions. These results suggest an optimum proceduremore » for forming a Ga{sub 2}O{sub 3} layer prior to the growth by atomic layer deposition of an Al{sub 2}O{sub 3} layer.« less
Authors:
 [1]
  1. Electronics Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)
Publication Date:
OSTI Identifier:
22122806
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 2; Other Information: (c) 2013 U.S. Government; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ADSORPTION; ALUMINIUM OXIDES; ANNEALING; ATOMS; CRYSTAL DEFECTS; GALLIUM ANTIMONIDES; GALLIUM IONS; GALLIUM OXIDES; LAYERS; N-TYPE CONDUCTORS; OXIDATION; PRESSURE RANGE MICRO PA; SEMICONDUCTOR MATERIALS; SURFACE PROPERTIES; SURFACES; X-RAY PHOTOELECTRON SPECTROSCOPY