Structural Property Study for GeSn Thin Films

Materials, vol. 13, pp. 3645

Abstract

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.

Authors 7

1. Liyao Zhang corresponding

   University of Shanghai for Science and Technology

   Affiliation as printed

   Department of Physics, University of Shanghai for Science and Technology, Shanghai 200093, China

2. Yuxin Song

   Shanghai Institute of Microsystem and Information Technology · State Key Laboratory of Functional Materials for Informatics

   Affiliation as printed

   State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Shanghai 200050, China

3. Nils von den Driesch Aachen

   RWTH Aachen University · Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   Jülich Aachen Research Alliance (JARA)-Institute Green IT, RWTH Aachen, 52074 Aachen, Germany

   Peter Grünberg Institute 9 (PGI-9) and JARA-Fundamentals of Future Information Technologies (JARA-FIT), Forschungszentrum Jülich, 52425 Jülich, Germany

4. Zhenpu Zhang

   Shanghai Institute of Microsystem and Information Technology · State Key Laboratory of Functional Materials for Informatics

   Affiliation as printed

   State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Shanghai 200050, China

5. Dan Buca

   Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   Peter Grünberg Institute 9 (PGI-9) and JARA-Fundamentals of Future Information Technologies (JARA-FIT), Forschungszentrum Jülich, 52425 Jülich, Germany

6. Detlev Grützmacher Aachen

   RWTH Aachen University · Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   Jülich Aachen Research Alliance (JARA)-Institute Green IT, RWTH Aachen, 52074 Aachen, Germany

   Peter Grünberg Institute 9 (PGI-9) and JARA-Fundamentals of Future Information Technologies (JARA-FIT), Forschungszentrum Jülich, 52425 Jülich, Germany

7. Shumin Wang corresponding

   Chalmers University of Technology · Shanghai Institute of Microsystem and Information Technology · State Key Laboratory of Functional Materials for Informatics

   Affiliation as printed

   Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Goteborg, Sweden

   State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Shanghai 200050, China