Kinetic study of the effects of H, O, N, S, NO, NO2 and O2 on the surface states of InGaAs and GaAs
| Autor: | Elmer A. Ogryzlo, Hongjun Li, George Gu |
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| Rok vydání: | 1995 |
| Předmět: | |
| Zdroj: | Journal of the Chemical Society, Faraday Transactions. 91:3021 |
| ISSN: | 1364-5455 0956-5000 |
| DOI: | 10.1039/ft9959103021 |
| Popis: | The photoluminescence intensities (PLIs) from 300 nm layers of In0.53Ga0.47As and GaAs have been used to monitor carrier lifetimes, in situ, during exposure of their surfaces to a number of gaseous species at 25 °C. PLIs have been observed to increase by a factor of 30–50 following a few seconds exposure to atomic hydrogen at gas-phase atom densities of ca. 1013 cm–3. For both semiconductors the PLI was found to be ca. 40% lower while the surface was being exposed to these atoms. Additional exposure of the InGaAs to H atoms was found to reduce the PLI from this maximum by a factor of 2–3. Both the InGaAs and GaAs surfaces that had been passivated by hydrogen atoms could be de-passivated in less than a second by exposure to O, N, NO or NO2 at comparable gas-phase densities or, at a much slower rate, by exposure to O2. The surfaces thus formed could be re-passivated by exposure to atomic hydrogen, but in the case of oxidizing species, the original behaviour of the InGaAs surface could only be restored with an HF wash. X-Ray photoelectron (XP) spectra of the surfaces under all these conditions were found to be indistinguishable. Exposure of the surface to S atoms was found to improve the passivation level of an HCl-washed surface by almost four orders of magnitude. |
| Databáze: | OpenAIRE |
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