Size Evolution of Ordered SiGe Islands Grown by Surface Thermal Diffusion on Pit-Patterned Si(100) Surface
1 CNISM and Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
2 CNR-Istituto di Fotonica e Nanotecnologie, via Anzani 42, 22100, Como, Italy
3 CNISM and LNESS, Dipartimento di Fisica, Politecnico di Milano (Polo Regionale di Como), Via Anzani 42, 22100, Como, Italy
4 Institute of Photonics Sciences, 08860, Barcelona, Spain
Nanoscale Research Letters 2010, 5:1921-1925 doi:10.1007/s11671-010-9781-0Published: 30 September 2010
The ordered growth of self-assembled SiGe islands by surface thermal diffusion in ultra high vacuum from a lithographically etched Ge stripe on pit-patterned Si(100) surface has been experimentally investigated. The total surface coverage of Ge strongly depends on the distance from the source stripe, as quantitatively verified by Scanning Auger Microscopy. The size distribution of the islands as a function of the Ge coverage has been studied by coupling atomic force microscopy scans with Auger spectro-microscopy data. Our observations are consistent with a physical scenario where island positioning is essentially driven by energetic factors, which predominate with respect to the local kinetics of diffusion, and the growth evolution mainly depends on the local density of Ge atoms.