Surface analysis of epitaxially grown GeSn alloys with Sn contents between 15% and 18%

Kormos L, Kratzer M, Kostecki K, Oehme M, Sikola T, Kasper E, Schulze J, Teichert C (2017)


Publication Type: Journal article

Publication year: 2017

Journal

Book Volume: 49

Pages Range: 297-302

Journal Issue: 4

DOI: 10.1002/sia.6134

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.

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How to cite

APA:

Kormos, L., Kratzer, M., Kostecki, K., Oehme, M., Sikola, T., Kasper, E.,... Teichert, C. (2017). Surface analysis of epitaxially grown GeSn alloys with Sn contents between 15% and 18%. Surface and Interface Analysis, 49(4), 297-302. https://dx.doi.org/10.1002/sia.6134

MLA:

Kormos, Lukas, et al. "Surface analysis of epitaxially grown GeSn alloys with Sn contents between 15% and 18%." Surface and Interface Analysis 49.4 (2017): 297-302.

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