Structural Property Study for GeSn Thin Films

Liyao Zhang; Yuxin Song; Nils von den Driesch; Zhenpu Zhang; Dan Buca; Detlev Grützmacher; Shumin Wang

doi:10.3390/ma13163645

Materials (Aug 2020)

Structural Property Study for GeSn Thin Films

Liyao Zhang,
Yuxin Song,
Nils von den Driesch,
Zhenpu Zhang,
Dan Buca,
Detlev Grützmacher,
Shumin Wang

Affiliations

Liyao Zhang: Department of Physics, University of Shanghai for Science and Technology, Shanghai 200093, China
Yuxin Song: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Shanghai 200050, China
Nils von den Driesch: Jülich Aachen Research Alliance (JARA)-Institute Green IT, RWTH Aachen, 52074 Aachen, Germany
Zhenpu Zhang: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Shanghai 200050, China
Dan Buca: Peter Grünberg Institute 9 (PGI-9) and JARA-Fundamentals of Future Information Technologies (JARA-FIT), Forschungszentrum Jülich, 52425 Jülich, Germany
Detlev Grützmacher: Jülich Aachen Research Alliance (JARA)-Institute Green IT, RWTH Aachen, 52074 Aachen, Germany
Shumin Wang: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Shanghai 200050, China

DOI: https://doi.org/10.3390/ma13163645
Journal volume & issue: Vol. 13, no. 16
p. 3645

Abstract

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The structural properties of GeSn thin films with different Sn concentrations and thicknesses grown on Ge (001) by molecular beam epitaxy (MBE) and on Ge-buffered Si (001) wafers by chemical vapor deposition (CVD) were analyzed through high resolution X-ray diffraction and cross-sectional transmission electron microscopy. Two-dimensional reciprocal space maps around the asymmetric (224) reflection were collected by X-ray diffraction for both the whole structures and the GeSn epilayers. The broadenings of the features of the GeSn epilayers with different relaxations in the ω direction, along the ω-2θ direction and parallel to the surface were investigated. The dislocations were identified by transmission electron microscopy. Threading dislocations were found in MBE grown GeSn layers, but not in the CVD grown ones. The point defects and dislocations were two possible reasons for the poor optical properties in the GeSn alloys grown by MBE.

Published in Materials

ISSN: 1996-1944 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering; Technology: Engineering (General). Civil engineering (General); Science: Natural history (General): Microscopy; Science: Physics: Descriptive and experimental mechanics
Website: http://www.mdpi.com/journal/materials/

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