Peak separation method for sub-lattice strain analysis at atomic resolution: Application to InAs/GaSb superlattice.
We report on a direct measurement of cation and anion sub-lattice strain in an InAs/GaSb type-II strained layer superlattice (T2SLs) using atomic resolution imaging and advanced image processing. Atomic column positions in InAs and GaSb are determined by separating the cation and anion peak intensities. Analysis of the InAs/GaSb T2SLs reveals the compressive strain in the nominal GaSb layer and tensile strain at interfaces between constituent layers, which indicate In incorporation into the nominal GaSb layer and the formation of GaAs like interfaces, respectively. The results are compared with the model-dependent X-ray diffraction measurements in terms of interfacial chemical intermixing and strain. Together, these techniques provide a robust measurement of atomic-scale strain which is vital to determine T2SL properties.
Dept of Materials Science and Engineering, University of Illinois, Urbana, IL 61801, USA; Seitz Materials Research Laboratory, University of Illinois, Urbana, IL 61801, USA.
Honggyu
H
Kim
Dept of Materials Science and Engineering, University of Illinois, Urbana, IL 61801, USA; Seitz Materials Research Laboratory, University of Illinois, Urbana, IL 61801, USA.
Yifei
Y
Meng
CEA/INAC/SP2M/LEMMA, 19 rue des Martyrs, 38 054 Grenoble, France.
Jean-Luc
JL
Rouviére
Dept of Materials Science and Engineering, University of Illinois, Urbana, IL 61801, USA; Seitz Materials Research Laboratory, University of Illinois, Urbana, IL 61801, USA. Electronic address: jianzuo@illinois.edu.
Jian-Min
JM
Zuo