Formation of grown-in defects in molecular beam epitaxial Ga(In)NP: Effects of growth conditions and postgrowth treatments
- Department of Physics, Chemistry and Biology, Linkoeping University, S-581 83 Linkoeping (Sweden)
- Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580 (Japan)
Effects of growth conditions and post-growth treatments, such as presence of N ions, N{sub 2} flow, growth temperature, In alloying, and postgrowth rapid thermal annealing (RTA), on formation of grown-in defects in Ga(In)NP prepared by molecular beam epitaxy are studied in detail by the optically detected magnetic resonance (ODMR) technique. Several common residual defects, such as two Ga-interstitial defects (i.e., Ga{sub i}-A and Ga{sub i}-B) and two unidentified defects with a g factor around 2 (denoted by S1 and S2), are closely monitored. Bombardment of impinging N ions on grown sample surface is found to facilitate formation of these defects. Higher N{sub 2} flow is shown to have an even more profound effect than a higher number of ions in introducing these defects. Incorporation of a small amount of In (e.g., 5.1%) in GaNP seems to play a minor role in the formation of the defects. In GaInNP with 45% of In; however, the defects were found to be abundant. Effect of RTA on the defects is found to depend on initial configurations of Ga{sub i}-related defects formed during the growth. In the alloys where the Ga{sub i}-A and Ga{sub i}-B defects are absent in the as-grown samples (i.e., GaNP grown at a low temperature of 460 deg. C), the concentrations of the two Ga{sub i} defects are found to increase after postgrowth RTA. This indicates that the defects originally introduced in the as-grown alloys have been transformed into the more thermally stable Ga{sub i}-A and Ga{sub i}-B during RTA. On the other hand, when the Ga{sub i}-A and Ga{sub i}-B are readily abundant (e.g., at higher growth temperatures ({>=}500 deg. C), RTA leads to a slight reduction of the Ga{sub i}-A and Ga{sub i}-B ODMR signals. The S2 defect is also shown to be thermally stable upon the RTA treatment.
- OSTI ID:
- 21133995
- Journal Information:
- Journal of Applied Physics, Vol. 103, Issue 6; Other Information: DOI: 10.1063/1.2895379; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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