کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5359781 | 1503705 | 2009 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
On the origin of aluminum-related cathodoluminescence emissions from sublimation grown 4H-SiC(112¯0)
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
The spatial origins of emissions from homoepitaxial 4H-SiC(112¯0) films have been investigated by cathodoluminescence, secondary ion mass spectrometry, and electron trajectory simulations. At 15 keV (300 K), the spectrum contained three peaks. The most intense peak corresponded (3.18 eV) to the nitrogen donor-to-valence band transition. The lesser two peaks at 2.94 eV and 2.75 eV involved aluminum and oxygen impurities, respectively; both impurities were determined to be in high concentrations in the film-substrate interfacial region. At 25 keV (300 K) the primary emission broadened into a band at â¼3.10 eV. Deconvolution revealed three peaks; the most intense emission was again the nitrogen donor-to-valence band transition. The remaining two peaks at 3.02 eV and 2.90 eV were consistent with transitions involving aluminum impurities. The former peak was not observed in the spectra obtained at lower electron beam energies and was correlated with the conduction band-to-aluminum acceptor level transition. Monte-Carlo simulations showed the origin of the 25 keV (300 K) spectrum was the film-substrate interface. An analysis of the aluminum impurity concentration in this region revealed that the cause of the 3.02 eV emission was a dramatic increase in the concentration of aluminum (3 Ã 1016 cmâ3 to 1 Ã 1018 cmâ3). The emissions comprising the 3.10 eV band were further investigated at 6 K and 25 keV. The difference in the intensity of the conduction band-to-aluminum acceptor level transition at 6 K and 300 K was attributed to thermal impurity ionization and the spike in the interfacial aluminum concentration previously described.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 255, Issues 13â14, 15 April 2009, Pages 6535-6539
Journal: Applied Surface Science - Volume 255, Issues 13â14, 15 April 2009, Pages 6535-6539
نویسندگان
S.M. Bishop, C.L. Jr., J.C. Molstad, F.A. Stevie, D.E. Barnhardt, R.F. Davis,