GaN grown on two-step cleaned C-terminated 6H–SiC by molecular-beam epitaxy
| Autor: | Z. P. Guan, J. Cabalu, A. L. Cai, S. Huang, J. Chen, R. E. Giedd, H. Porter |
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| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 19:280-286 |
| ISSN: | 1520-8559 0734-2101 |
| DOI: | 10.1116/1.1329120 |
| Popis: | A contaminant-free C-terminated 6H–SiC (0001) surface has been successfully prepared by a two-step method, which combines H2:He (1:1) plasma and heating at 940 °C for 100 min. On this surface, a high-quality GaN (0001) thin film is obtained by radio-frequency nitrogen-plasma- assisted molecular-beam epitaxy. Near-band-edge emissions have been observed from some of these epilayers, depending primarily on the substrate surface conditions. Auger electron spectroscopy measurements show that temperatures of 940–1245 °C are necessary to thermally desorb the oxide and carbide from 6H–SiC substrates. At 1040 °C for the C-face SiC and 1150 °C for the Si-face SiC, crystalline damage was reported in the form of graphite formation on the surface. This graphite was observed through x-ray photoelectron spectroscopy. Structural analysis by x-ray diffraction and photoluminescence indicates very good in-plane alignment of the GaN epilayers as the substrates are cleaned using H2:He (1:1) plasma at 940 °C for 100 min. |
| Databáze: | OpenAIRE |
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