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Properties of GaAs(001) surfaces thermally annealed in vacuum.
- Source :
-
Journal of Applied Physics . Feb2009, Vol. 105 Issue 4, pN.PAG. 7p. 3 Diagrams, 1 Chart, 7 Graphs. - Publication Year :
- 2009
-
Abstract
- Thermal degradation of GaAs(001) surfaces has been studied using spectroscopic ellipsometry (SE), optical microscopy, ex situ atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) techniques. The SE data suggest that thermal annealing causes no or little influence on the surface native oxide layer at temperatures T≤500 °C. Microscopic roughening starts to occur on GaAs surface at T>500 °C, giving maximum AFM roughness (rms∼14 nm) at 540 °C, and then tends to smoothened at T>540 °C (rms∼2.5 nm at 580 °C). Macroscopically roughened surfaces are observed at T>500 °C, becoming more pronounced at higher annealing temperature. The Ga droplets are also observed at T≥600 °C that lead to catastrophically damaged surfaces and make SE measurement impossible. The XPS data indicate thinning of the native GaAs oxide in the limited temperature range 450<T<580 °C; however, annealing at T≥580 °C leads to coverage with thermal oxides (Ga2O and As2O3). The naturally grown GaAs oxide is also found to act as a good passivation film against annealing-induced PL degradation. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00218979
- Volume :
- 105
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Journal of Applied Physics
- Publication Type :
- Academic Journal
- Accession number :
- 36823283
- Full Text :
- https://doi.org/10.1063/1.3078178