Low-temperature epitaxial growth of Ge-rich Ge–Si–C alloys: Microstructure, Raman studies, and optical properties
| Autor: | M. Krishnamurthy, B.-K. Yang, W. H. Weber |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 84:2011-2017 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.368354 |
| Popis: | Low-temperature (∼200 °C) molecular beam epitaxy of Ge-rich Ge1−x−ySiyCx alloys grown on Si(100) have been investigated by in situ reflection high-energy electron diffraction, ex situ x-ray diffraction, transmission electron microscopy, Raman scattering, and ellipsometry. The Si contents were either ∼20 or ∼40 at % and the C concentrations were nominally varied from zero up to ∼8 at %. Selected samples were annealed in an Ar ambient at 750 °C to evaluate the stability of the thin films. With increasing C concentration, the epitaxial growth mode changes from two-dimensional (2D) layer growth to 3D island growth. Under the growth conditions studied, the GeSiC films have a tendency to form planar defects, whose density increases with increasing C and Si concentrations. The x-ray diffraction data show that the lattice parameter decreases with increasing C concentration. It is estimated that a maximum of ∼2–3 at % C is substitutionally incorporated into these films. Raman spectra of the alloy films show that t... |
| Databáze: | OpenAIRE |
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