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arXiv · 1907.07169

The formation of intermediate layers in covered Ge/Si heterostructures with low-temperature quantum dots: a study using high-resolution transmission electron microscopy and Raman spectroscopy

Mikhail S. Storozhevykh·Larisa V. Arapkina·Sergey M. Novikov·Valentyn S. Volkov·Oleg V. Uvarov·Vladimir A. Yuryev
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Abstract

The method of software analysis of high-resolution TEM images using the peak pairs algorithm in combination with Raman spectroscopy was employed to study lattice deformations in Ge/Si(001) structures with low-temperature Ge quantum dots. It was found that the stresses do not spread in a thick Si layer above quantum dots, but completely relax via the formation of a thin boundary layer of mixed composition. However, intermixing of Ge and Si is absent beneath the Ge layer in samples with a Ge coverage of 10 \r{A}. Besides intermixing was not observed at all, both beneath and above the Ge layer, in samples with a Ge coverage of 6 \r{A} or less. This may be due to the predominance of Ge diffusion into the Si matrix from the {105} facets of Ge huts, not from the Ge wetting layer, at low temperatures of the Ge/Si structure deposition. The critical thickness of Si coverage at which the intense stress-induced diffusion takes place is determined to lie in the range from 5 to 8 nm.

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Mikhail S. Storozhevykh, Larisa V. Arapkina, Sergey M. Novikov, Valentyn S. Volkov, Oleg V. Uvarov, Vladimir A. Yuryev. 2019-07-16. The formation of intermediate layers in covered Ge/Si heterostructures with low-temperature quantum dots: a study using high-resolution transmission electron microscopy and Raman spectroscopy. https://doi.org/10.1088/1361-6641/ab73f1

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