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

Journal Article · Sun Jul 14 00:00:00 EDT 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4812740· OSTI ID:22122806

Bermudez, V. M. ^[1]

---

1. Electronics Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)

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 procedure 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.

• OSTI ID: 22122806
• Journal Information: Journal of Applied Physics, Vol. 114, Issue 2; Other Information: (c) 2013 U.S. Government; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

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