Microscopy and Microanalysis

Materials Applications

Compositional Analysis with Atomic Column Spatial Resolution by 5th-Order Aberration-Corrected Scanning Transmission Electron Microscopy

David Hernández-Maldonadoa1 c1, Miriam Herreraa1, Pablo Alonso-Gonzáleza2, Yolanda Gonzáleza2, Luisa Gonzáleza2, Jaume Gazqueza3, María Varelaa3, Stephen J. Pennycooka3, María de la Paz Guerrero-Lebreroa4, Joaquín Pizarroa4, Pedro L. Galindoa4 and Sergio I. Molinaa1

a1 Departamento de Ciencia de los Materiales e I.M. y Q.I., Facultad de Ciencias, Universidad de Cádiz, Campus Río San Pedro, s/n, 11510 Puerto Real, Cádiz, Spain

a2 Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8 (PTM), 28760-Tres Cantos (Madrid), Spain

a3 Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA

a4 Departamento de Lenguajes y Sistemas Informáticos, CASEM, Universidad de Cádiz, Campus Río San Pedro, s/n, 11510 Puerto Real, Cádiz, Spain

Abstract

We show in this article that it is possible to obtain elemental compositional maps and profiles with atomic-column resolution across an InxGa1−xAs multilayer structure from 5th-order aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images. The compositional profiles obtained from the analysis of HAADF-STEM images describe accurately the distribution of In in the studied multilayer in good agreement with Muraki's segregation model [Muraki, K., Fukatsu, S., Shiraki, Y. & Ito, R. (1992). Surface segregation of In atoms during molecular beam epitaxy and its influence on the energy levels in InGaAs/GaAs quantums wells. Appl Phys Lett 61, 557–559].

(Received August 04 2010)

(Accepted January 31 2011)

(Online publication May 27 2011)

Correspondence:

c1 Corresponding author. E-mail: david.hernandez@uca.es