The growth of nanometer Si/SiGe/Si quantum well wires with local molecular beam epitaxy in dependence on the shadow mask geometry

authored by: Myeongcheol Kim, H. J. Osten, A. Wolff, C. Quick, H. P. Zeindl, J. Klatt, D. Knoll
Abstract: We report on molecular beam epitaxial growth of nanometer structures using shadow masks deposited directly onto the substrate. A preparation method for these masks with dimensions of only few 10 nm based on optical lithography is shown using a spacer technology. Si/Si_0.8Ge_0.2/Si quantum well wires (QWRs) smaller than 100 nm were grown. The obtained wire shapes are investigated by scanning and transmission electron microscopy as a function of shadow mask design and evaporation source geometry. Both the mask geometry and the surface diffusion of adatoms have to be considered for predicting wire shapes. From an analysis of different grown wires it becomes evident that the geometries of the mask and deposition system play the most important role in deciding the shape of QWRs. At high growth temperatures an enhanced surface diffusion causes a modulation of the Ge content and lowers the thickness of the SiGe quantum well. For the growth at lower temperatures, the relation between mask geometry and wire shape can be treated with purely geometrical arguments.
External Organisation(s): Leibniz Institute for High Performance Microelectronics (IHP)
Type: Article
Journal: Journal of crystal growth
Volume: 167
Pages: 508-515
No. of pages: 8
ISSN: 0022-0248
Publication date: 10.1996
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Condensed Matter Physics, Inorganic Chemistry, Materials Chemistry
Electronic version(s): https://doi.org/10.1016/0022-0248(96)00255-2 (Access: Closed)

BibTeX

@article{2061641bb6cd42a99730d7b1895c8f21,
title = "The growth of nanometer Si/SiGe/Si quantum well wires with local molecular beam epitaxy in dependence on the shadow mask geometry",
abstract = "We report on molecular beam epitaxial growth of nanometer structures using shadow masks deposited directly onto the substrate. A preparation method for these masks with dimensions of only few 10 nm based on optical lithography is shown using a spacer technology. Si/Si0.8Ge0.2/Si quantum well wires (QWRs) smaller than 100 nm were grown. The obtained wire shapes are investigated by scanning and transmission electron microscopy as a function of shadow mask design and evaporation source geometry. Both the mask geometry and the surface diffusion of adatoms have to be considered for predicting wire shapes. From an analysis of different grown wires it becomes evident that the geometries of the mask and deposition system play the most important role in deciding the shape of QWRs. At high growth temperatures an enhanced surface diffusion causes a modulation of the Ge content and lowers the thickness of the SiGe quantum well. For the growth at lower temperatures, the relation between mask geometry and wire shape can be treated with purely geometrical arguments.",
author = "Myeongcheol Kim and Osten, {H. J.} and A. Wolff and C. Quick and Zeindl, {H. P.} and J. Klatt and D. Knoll",
year = "1996",
month = oct,
doi = "10.1016/0022-0248(96)00255-2",
language = "English",
volume = "167",
pages = "508--515",
journal = "Journal of crystal growth",
issn = "0022-0248",
publisher = "Elsevier",
number = "3-4",
}