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arXiv · 1205.6039

Shape evolution of MBE grown Si$_{1-x}$Ge$_{x}$ structures on high index Si(5 5 12) surfaces: A temperature dependent study

J. K. Dash·A. Rath·R. R. Juluri·P. V. Satyam
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Abstract

The morphological evolution and the effect of growth temperature on size, orientation and composition of molecular beam epitaxy grown Ge-Si islands on Si(5 5 12) surfaces have been investigated in the temperature range from room temperature (RT) to 800$^\circ$C. Two modes of substrate heating i.e. radiative heating (RH) and direct current heating (DH) have been used. The post-growth characterization was carried out ex situ by scanning electron microscopy (SEM), cross-sectional transmission electron microscopy (X-TEM) and Rutherford backscattering spectrometry (RBS). In the RH case, we found spherical island structures at 600$^\circ$C with a bimodal distribution and upon increasing temperature, the structures got faceted at 700$^\circ$C. At 800$^\circ$C thick ($\sim$ 122nm) dome like structures are formed bounded by facets. While in the case of DC heating, after the optimum critical temperature 600$^\circ$C, well aligned trapezoidal Si$_{1-x}$Ge$_x$ structures with a graded composition starts forming along the step edges. Interestingly, these aligned structures have been found only around 600$^\circ$C, neither at low temperature nor at higher temperatures.

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J. K. Dash, A. Rath, R. R. Juluri, P. V. Satyam. 2012-05-28. Shape evolution of MBE grown Si$_{1-x}$Ge$_{x}$ structures on high index Si(5 5 12) surfaces: A temperature dependent study. https://doi.org/10.1088/0022-3727/45/45/455303

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