Fabrication of GeSn-multiple quantum wells by overgrowth of Sn on Ge by using molecular beam epitaxy

Journal Article · Mon Dec 28 04:00:00 EST 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4938746· OSTI ID:22486302

Oliveira, F. ^[1]; Fischer, I. A.; Schulze, J. ^[1]; Benedetti, A. ^[2]; Zaumseil, P. ^[3]; Cerqueira, M. F.; Vasilevskiy, M. I. ^[4]; Stefanov, S.; Chiussi, S. ^[5]

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1. Institute for Semiconductor Engineering, University of Stuttgart, 70569 Stuttgart (Germany)
2. CACTI, Univ. de Vigo, Campus Universitario Lagoas Marcosende 15, Vigo (Spain)
3. IHP GmbH, Innovations for High Performance Microelectronics, Leibniz-Institut für innovative Mikroelektronik, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany)
4. Centre of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal)
5. Dpto. Fisica Aplicada, Univ. de Vigo, Rua Maxwell s/n, Campus Universitario Lagoas Marcosende, Vigo (Spain)

We report on the fabrication and structural characterization of epitaxially grown ultra-thin layers of Sn on Ge virtual substrates (Si buffer layer overgrown by a 50 nm thick Ge epilayer followed by an annealing step). Samples with 1 to 5 monolayers of Sn on Ge virtual substrates were grown using solid source molecular beam epitaxy and characterized by atomic force microscopy. We determined the critical thickness at which the transition from two-dimensional to three-dimensional growth occurs. This transition is due to the large lattice mismatch between Ge and Sn (≈14.7%). By depositing Ge on top of Sn layers, which have thicknesses at or just below the critical thickness, we were able to fabricate ultra-narrow GeSn multi-quantum-well structures that are fully embedded in Ge. We report results on samples with one and ten GeSn wells separated by 5 and 10 nm thick Ge spacer layers that were characterized by high resolution transmission electron microscopy and X-ray diffraction. We discuss the structure and material intermixing observed in the samples.

• OSTI ID: 22486302
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 26 Vol. 107; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANNEALING
ATOMIC FORCE MICROSCOPY
CRYSTAL DEFECTS
FABRICATION
LAYERS
MOLECULAR BEAM EPITAXY
QUANTUM WELLS
SUBSTRATES
THICKNESS
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
TWO-DIMENSIONAL SYSTEMS
X-RAY DIFFRACTION