Enhancing elastic stress relaxation in SiGe/Si heterostructures by Si pillar necking

[1 ]Laboratory for Solid State Physics, ETH Zürich, Otto-Stern-Weg 1, Zürich CH-8093, Switzerland

[2 ]Electron Microscopy Center Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf CH-8600, Switzerland

[3 ]L-NESS and Department of Materials Science, Università di Milano-Bicocca, Via Cozzi 55, Milano I-20125, Italy

[4 ]Institute for Scientific Computing, Technische Universität Dresden, Willers-Bau B – Zellescher Weg 12-14, Dresden D-01062, Germany

[5 ]L-NESS and Department of Physics, Politecnico di Milano and IFN-CNR, Via Anzani 42, Como I-22100, Italy

[6 ]CSEM, Rue Jaquet-Droz 1, Neuchâtel CH-2002, Switzerland

[7 ]Advanced Materials and Surfaces Department Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf CH-8600, Switzerland