GaAs/Ge crystals grown on Si substrates patterned down to the micron scale

Journal Article · Sun Feb 07 00:00:00 EST 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4940379· OSTI ID:22494983

Kreiliger, T.; Falub, C. V.; Känel, H. von ^[1]; Meduňa, M. ^[2]; Salvalaglio, M.; Miglio, L. ^[3]; Isa, F. ^[1]; Barthazy Meier, E.; Müller, E. ^[4]; Isella, G. ^[5]

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1. Laboratory for Solid State Physics, ETH Zürich, Otto-Stern-Weg. 1, CH-8093 Zürich (Switzerland)
2. Department of Condensed Matter Physics, Masaryk University, Kotlářská 2, CZ-61137 Brno (Czech Republic)
3. L-NESS, Department of Materials Science, Università di Milano-Bicocca, Via R. Cozzi 55, I-20125 Milano (Italy)
4. Scientific Center for Optical and Electron Microscopy (ScopeM), ETH Zürich, Auguste-Piccard-Hof 1, CH-8093 Zürich (Switzerland)
5. L-NESS and Department of Physics, Politecnico di Milano, via Anzani 42, I-22100 Como (Italy)

Monolithic integration of III-V compounds into high density Si integrated circuits is a key technological challenge for the next generation of optoelectronic devices. In this work, we report on the metal organic vapor phase epitaxy growth of strain-free GaAs crystals on Si substrates patterned down to the micron scale. The differences in thermal expansion coefficient and lattice parameter are adapted by a 2-μm-thick intermediate Ge layer grown by low-energy plasma enhanced chemical vapor deposition. The GaAs crystals evolve during growth towards a pyramidal shape, with lateral facets composed of (111) planes and an apex formed by (137) and (001) surfaces. The influence of the anisotropic GaAs growth kinetics on the final morphology is highlighted by means of scanning and transmission electron microscopy measurements. The effect of the Si pattern geometry, substrate orientation, and crystal aspect ratio on the GaAs structural properties was investigated by means of high resolution X-ray diffraction. The thermal strain relaxation process of GaAs crystals with different aspect ratio is discussed within the framework of linear elasticity theory by Finite Element Method simulations based on realistic geometries extracted from cross-sectional scanning electron microscopy images.

• OSTI ID: 22494983
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 5; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASPECT RATIO
CHEMICAL VAPOR DEPOSITION
CRYSTALS
FINITE ELEMENT METHOD
GALLIUM ARSENIDES
LATTICE PARAMETERS
OPTOELECTRONIC DEVICES
SCANNING ELECTRON MICROSCOPY
SUBSTRATES
TRANSMISSION ELECTRON MICROSCOPY
VAPOR PHASE EPITAXY
X-RAY DIFFRACTION