Formation, structure, and phonon confinement effect of nanocrystalline Si1−xGex in SiO2‐Si‐Ge cosputtered films
| Autor: | Yifan Yang, Xinglong Wu, Dazhi Hu, Jinyou Shen, G. S. Huang, G. G. Siu |
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| Rok vydání: | 2004 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 96:5239-5242 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.1772888 |
| Popis: | Using magnetron cosputtering of SiO2, Ge, and Si targets, Si-based SiO2:Ge:Si films were fabricated for exploring the influence of Si target proportion (PSi) and annealing temperature (Ta) on formation, local structure, and phonon properties of nanocrystalline Si1−xGex (nc‐Si1−xGex). At low PSi and Ta higher than 800°C, no nc‐Si1−xGex but a kind of composite nanocrystal consisting of a Ge core, GeSi shell, and amorphous Si outer shell is formed in the SiO2 matrix. At moderate PSi, nc‐Si1−xGex begins to be formed at Ta=800°C and coexists with nc‐Ge at Ta=1100°C. At high PSi, it was disclosed that both optical phonon frequency and lattice spacing of nc‐Si1−xGex increase with raising Ta. The possible origin of this phenomenon is discussed by considering three factors, the phonon confinement, strain effect, and composition variation of nc‐Si1−xGex. This work will be helpful in understanding the growth process of ternary GeSiO films and beneficial to further investigations on optical properties of nc‐Ge1−xSix ... |
| Databáze: | OpenAIRE |
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