| Autor: |
Constantin Logofatu, M. F. Lazarescu, Catalin Negrila, C. Cotirlan, A. S. Manea, F. Ungureanu, R. V. Ghita |
| Rok vydání: |
2008 |
| Předmět: |
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| Zdroj: |
Journal of Crystal Growth. 310:1576-1582 |
| ISSN: |
0022-0248 |
| DOI: |
10.1016/j.jcrysgro.2007.11.001 |
| Popis: |
Angle-resolved X-ray photoelectron spectroscopy (ARXPS) analysis has been performed on GaAs (1 0 0) surfaces in different conditions as naturally oxidized, Ar + ion sputtering ( E =1–5 keV) and chemical etching in H 2 SO 4 /H 2 O 2 /H 2 O (3:1:1). The most sensitive angle to the surface compositional changes was the take-off angle (TOA): 25°. Native oxide phases on GaAs consist of a mixture of Ga 2 O 3 , As 2 O 3 and As 2 O 5 . Ar + ion sputtering procedure modifies the surface composition, in the altered layer where the concentration ratio C Ga / C As tends to 1.5–1.6. Wet chemical etching removes the oxide layer and the As-rich region from the surface. In the experiment combining chemical etching with Ar + ion sputtering for cleaning purpose, the native oxides are removed from the surface and C Ga / C As tends to stoichiometry. The experiment on native oxide reconstruction after storage in high-vacuum conditions ( p ∼10 −8 Torr) provides evidence of the high reactivity of GaAs (1 0 0) surfaces. We have observed the presence of an As oxide (BE=43 eV) within a concentration range of 2–3%. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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