Deviations from Vegard’s law in semiconductor thin films measured with X-ray diffraction and Rutherford backscattering: The Ge1-ySny and Ge1-xSix cases.

Autor:	Chi Xu, Senaratne, Charutha L., Culbertson, Robert J., Kouvetakis, John, Menéndez, José
Předmět:	RUTHERFORD backscattering spectrometry SEMICONDUCTOR films THIN films EPITAXIAL layers X-ray diffraction
Zdroj:	Journal of Applied Physics; 2017, Vol. 122 Issue 12, p125702-1-125702-10, 10p, 1 Chart, 6 Graphs
Abstrakt:	The compositional dependence of the lattice parameter in Ge1-ySny alloys has been determined from combined X-ray diffraction and Rutherford Backscattering (RBS) measurements of a large set of epitaxial films with compositions in the 01-xSix films yield a bowing parameter θGeSi =-0.0253(30) Å , in excellent agreement with the classic work by Dismukes. When the same methodology is applied to Ge1-ySny alloy films, it is found that the bowing parameter θGeSn is zero within experimental error, so that the system follows Vegard’s law. This is in qualitative agreement with ab initio theory, but the value of the experimental bowing parameter is significantly smaller than the theoretical prediction. Possible reasons for this discrepancy are discussed in detail. [ABSTRACT FROM AUTHOR]
Databáze:	Complementary Index
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