Alloying and Strain Relaxation in SiGe Islands Grown on Pit-Patterned Si(001) Substrates Probed by Nanotomography
1 Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstraße 20, 01069, Dresden, Germany
2 Institut für Halbleitertechnik, Pfaffenwaldring 47, 70569, Stuttgart, Germany
3 Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569, Stuttgart, Germany
Nanoscale Research Letters 2009, 4:1073-1077 doi:10.1007/s11671-009-9360-4Published: 6 June 2009
The three-dimensional composition profiles of individual SiGe/Si(001) islands grown on planar and pit-patterned substrates are determined by atomic force microscopy (AFM)-based nanotomography. The observed differences in lateral and vertical composition gradients are correlated with the island morphology. This approach allowed us to employ AFM to simultaneously gather information on the composition and strain of SiGe islands. Our quantitative analysis demonstrates that for islands with a fixed aspect ratio, a modified geometry of the substrate provides an enhancement of the relaxation, finally leading to a reduced intermixing.