Details
| Original language | English |
|---|---|
| Pages (from-to) | 171-176 |
| Number of pages | 6 |
| Journal | Journal of Crystal Growth |
| Volume | 457 |
| Early online date | 29 Jun 2016 |
| Publication status | Published - 1 Jan 2017 |
Abstract
We report on the impact of a surfactant on the growth mode and strain relaxation of thin Ge films on Si0.21Ge0.79 virtual substrates grown by surfactant mediated epitaxy on Si(001) wafers. Ge epitaxy without surfactant results in island formation after deposition of only 5 nm Ge. A certain part of the strain in the Ge islands is relaxed via interfacial misfit dislocations, which are located within the core part of the islands. We discuss the possibilities for the occurrence of three-dimensional growth at low Ge layer thickness. The use of Sb as a surfactant suppresses three-dimensional islanding and enables the growth of smooth pseudomorphically strained Ge films on Si0.21Ge0.79(001) virtual substrates up to a thickness of 10 nm. At thicknesses higher than 20 nm, the films relax via the formation of a misfit dislocation network at the Ge/ Si1−xGex interface. The surface roughness of up to 30 nm thick layers is below 1.6 nm. Our experimental results corroborate the calculated thickness for plastic relaxation of Ge on Si1−xGex. The effect of the surfactant on the growth of the virtual substrate and on the subsequent growth of Ge on Si0.21Ge0.79 is discussed.
Keywords
- A1. Surface morphology, A3. Molecular beam epitaxy, A3. Surfactant mediated epitaxy, B1. Germanium silicon alloys, B2. Strained Ge, B2. Virtual substrates
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Condensed Matter Physics
- Chemistry(all)
- Inorganic Chemistry
- Materials Science(all)
- Materials Chemistry
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In: Journal of Crystal Growth, Vol. 457, 01.01.2017, p. 171-176.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Surfactant-mediated epitaxy of thin germanium films on SiGe(001) virtual substrates
AU - Schmidt, J.
AU - Tetzlaff, D.
AU - Bugiel, E.
AU - Wietler, T. F.
N1 - Publisher Copyright: © 2016 Elsevier B.V. Copyright: Copyright 2016 Elsevier B.V., All rights reserved.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - We report on the impact of a surfactant on the growth mode and strain relaxation of thin Ge films on Si0.21Ge0.79 virtual substrates grown by surfactant mediated epitaxy on Si(001) wafers. Ge epitaxy without surfactant results in island formation after deposition of only 5 nm Ge. A certain part of the strain in the Ge islands is relaxed via interfacial misfit dislocations, which are located within the core part of the islands. We discuss the possibilities for the occurrence of three-dimensional growth at low Ge layer thickness. The use of Sb as a surfactant suppresses three-dimensional islanding and enables the growth of smooth pseudomorphically strained Ge films on Si0.21Ge0.79(001) virtual substrates up to a thickness of 10 nm. At thicknesses higher than 20 nm, the films relax via the formation of a misfit dislocation network at the Ge/ Si1−xGex interface. The surface roughness of up to 30 nm thick layers is below 1.6 nm. Our experimental results corroborate the calculated thickness for plastic relaxation of Ge on Si1−xGex. The effect of the surfactant on the growth of the virtual substrate and on the subsequent growth of Ge on Si0.21Ge0.79 is discussed.
AB - We report on the impact of a surfactant on the growth mode and strain relaxation of thin Ge films on Si0.21Ge0.79 virtual substrates grown by surfactant mediated epitaxy on Si(001) wafers. Ge epitaxy without surfactant results in island formation after deposition of only 5 nm Ge. A certain part of the strain in the Ge islands is relaxed via interfacial misfit dislocations, which are located within the core part of the islands. We discuss the possibilities for the occurrence of three-dimensional growth at low Ge layer thickness. The use of Sb as a surfactant suppresses three-dimensional islanding and enables the growth of smooth pseudomorphically strained Ge films on Si0.21Ge0.79(001) virtual substrates up to a thickness of 10 nm. At thicknesses higher than 20 nm, the films relax via the formation of a misfit dislocation network at the Ge/ Si1−xGex interface. The surface roughness of up to 30 nm thick layers is below 1.6 nm. Our experimental results corroborate the calculated thickness for plastic relaxation of Ge on Si1−xGex. The effect of the surfactant on the growth of the virtual substrate and on the subsequent growth of Ge on Si0.21Ge0.79 is discussed.
KW - A1. Surface morphology
KW - A3. Molecular beam epitaxy
KW - A3. Surfactant mediated epitaxy
KW - B1. Germanium silicon alloys
KW - B2. Strained Ge
KW - B2. Virtual substrates
UR - http://www.scopus.com/inward/record.url?scp=84978835215&partnerID=8YFLogxK
U2 - 10.1016/j.jcrysgro.2016.06.053
DO - 10.1016/j.jcrysgro.2016.06.053
M3 - Article
AN - SCOPUS:84978835215
VL - 457
SP - 171
EP - 176
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
SN - 0022-0248
ER -