Sn-enriched Ge/GeSn nanostructures grown by MBE on (001) GaAs and Si wafers

• Published in: Semiconductors (Woodbury, N.Y.) Vol. 49; no. 12; pp. 1564 - 1570
• Main Authors: Sadofyev, Yu. G., Martovitsky, V. P., Klekovkin, A. V., Saraykin, V. V., Vasil’evskii, I. S.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2015; Springer
• Subjects: 2015; ANNEALING; CRACKS; CRYSTALS; DECOMPOSITION; DEFORMATION; GALLIUM ARSENIDES; GERMANIUM; LAYERS; Magnetic Materials; Magnetism; March 10–14; MATERIALS SCIENCE; MOLECULAR BEAM EPITAXY; MONOCLINIC LATTICES; NANOSTRUCTURES; Nizhny Novgorod; Physics; Physics and Astronomy; RELAXATION; SILICON; SOLID SOLUTIONS; STRESSES; SURFACES; TIN; XIX Symposium “Nanophysics and Nanoelectronics”; Germanium; Phase Decay; RHEED Pattern; Plastic Relaxation; GaAs
• ISSN: 1063-7826; 1090-6479
• DOI: 10.1134/S1063782615120179

Elastically stressed metastable GeSn layers with a tin molar fraction as large as 0.185 are grown on (001) Si and GaAs wafers covered with a germanium buffer layer. A set of wafers with a deviation angle in the range 0°–10° is used. It is established that the GeSn crystal undergoes monoclinic deformation with the angle β to 88° in addition to tetragonal deformation. Misorientation of the wafers surface results in increasing efficiency of the incorporation of tin adatoms into the GeSn crystal lattice. Phase separation in the solid solution upon postgrowth annealing of the structures begins long before the termination of plastic relaxation of elastic heteroepitaxial stresses. Tin released as a result of GeSn decomposition predominantly tends to be found on the surface of the sample. Manifestations of the brittle–plastic mechanism of the relaxation of stresses resulting in the occurrence of microcracks in the subsurface region of the structures under investigation are found.