%0 Journal Article %1 kormos2017surface %A Kormoš, L. %A Kratzer, M. %A Kostecki, K. %A Oehme, M. %A Šikola, T. %A Kasper, E. %A Schulze, J. %A Teichert, C. %B 4 %D 2017 %J Surface and Interface Analysis %K iht j.schulze.iht journal %P 297-302 %T Surface analysis of epitaxially grown GeSn alloys with Sn contents between 15% and 18% %U https://onlinelibrary.wiley.com/doi/abs/10.1002/sia.6134 %V 49 %X Abstract Metastable Germanium–tin (GeSn) layers with rather high Sn content between 15% and 18% grown on Si substrates by molecular beam epitaxy were analyzed for the morphological changes on a surface before and after reaching critical layer parameters (thickness, Sn content, and growth temperature) for surface roughening. Atomic-force microscopy investigations were performed as a function of thickness and separately for varying Sn concentrations in the GeSn layer. Epitaxial growth of metastable, uniform GeSn (15% Sn content) layers is obtained up to a critical thickness which increases from about 80 to above 200 nm by reducing the nominal growth temperature from 160 to 140 °C. Phase separation of the complete layer into tin-rich surface protrusions and a Ge-rich matrix takes place beyond the critical thickness. This surface roughening via phase separation was not observed in earlier investigations with lower Sn concentrations (<6%). Tin depletion in the GeSn matrix was confirmed by using energy-dispersive X-ray spectroscopy measurements showing residual Sn concentration below 5%. Additionally, creation of droplets with high concentration of tin on the surfaces was confirmed by energy-dispersive X-ray spectroscopy. Copyright © 2016 John Wiley & Sons, Ltd.

@article{kormos2017surface, abstract = {Abstract Metastable Germanium–tin (GeSn) layers with rather high Sn content between 15% and 18% grown on Si substrates by molecular beam epitaxy were analyzed for the morphological changes on a surface before and after reaching critical layer parameters (thickness, Sn content, and growth temperature) for surface roughening. Atomic-force microscopy investigations were performed as a function of thickness and separately for varying Sn concentrations in the GeSn layer. Epitaxial growth of metastable, uniform GeSn (15% Sn content) layers is obtained up to a critical thickness which increases from about 80 to above 200 nm by reducing the nominal growth temperature from 160 to 140 °C. Phase separation of the complete layer into tin-rich surface protrusions and a Ge-rich matrix takes place beyond the critical thickness. This surface roughening via phase separation was not observed in earlier investigations with lower Sn concentrations (<6%). Tin depletion in the GeSn matrix was confirmed by using energy-dispersive X-ray spectroscopy measurements showing residual Sn concentration below 5%. Additionally, creation of droplets with high concentration of tin on the surfaces was confirmed by energy-dispersive X-ray spectroscopy. Copyright © 2016 John Wiley & Sons, Ltd. }, added-at = {2018-11-19T10:58:26.000+0100}, author = {Kormoš, L. and Kratzer, M. and Kostecki, K. and Oehme, M. and Šikola, T. and Kasper, E. and Schulze, J. and Teichert, C.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2aa83832996688fe0e11b83b5237cf1d3/ihtpublikation}, interhash = {8630a0bbe91eb687b55137097902c9ba}, intrahash = {aa83832996688fe0e11b83b5237cf1d3}, journal = {Surface and Interface Analysis}, keywords = {iht j.schulze.iht journal}, pages = {297-302}, series = 4, timestamp = {2018-11-19T09:58:36.000+0100}, title = {Surface analysis of epitaxially grown GeSn alloys with Sn contents between 15% and 18%}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/sia.6134}, volume = 49, year = 2017 }