Beneficial defects: exploiting the intrinsic polishing-induced wafer roughness for the catalyst-free growth of Ge in-plane nanowires
1 Department of Materials, ETH Zurich, Hönggerbergring 64, Zürich 8093, Switzerland
2 Dipartimento di Fisica, Università di Roma ‘Tor Vergata’, Via della Ricerca Scientifica 1, Rome 0133, Italy
3 Dipartimento di Ingegneria dell’Impresa, ‘Mario Lucertini’, via del Politecnico 1, Rome 00133, Italy
4 Institute for Future Environments and School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane QLD 4001, Australia
Nanoscale Research Letters 2014, 9:358 doi:10.1186/1556-276X-9-358Published: 16 July 2014
We outline a metal-free fabrication route of in-plane Ge nanowires on Ge(001) substrates. By positively exploiting the polishing-induced defects of standard-quality commercial Ge(001) wafers, micrometer-length wires are grown by physical vapor deposition in ultra-high-vacuum environment. The shape of the wires can be tailored by the epitaxial strain induced by subsequent Si deposition, determining a progressive transformation of the wires in SiGe faceted quantum dots. This shape transition is described by finite element simulations of continuous elasticity and gives hints on the equilibrium shape of nanocrystals in the presence of tensile epitaxial strain.
81.07.Gf; 68.35.bg; 68.35.bj; 62.23.Eg