Publication Date:
2014-10-17
Description:
Ultrathin C-doped Ge (Ge:C) buffers are used as effective buffer layers to grow thin and smooth Si 1−x Ge x relaxed virtual substrates on Si over a wide range of Ge content ( x = 0.23, 0.38, 0.50, 0.65, 1) by ultrahigh vacuum chemical vapor deposition. High degree of relaxation (≥90%) in thin Si 1−x Ge x films (∼50 nm thick) is demonstrated using this approach without additional annealing. Raman data suggest that the Ge:C buffers are still under compressive stress with the subsequent Si 1−x Ge x layer growth. A low threading dislocation density of the order of ∼6 × 10 4 cm −2 is obtained from the relaxed 500-nm Si 0.77 Ge 0.23 film grown using this method.
Print ISSN:
0003-6951
Electronic ISSN:
1077-3118
Topics:
Physics
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