Nonstoichiometric growth and cluster formation in low temperature grown GaAsSb for terahertz-applications Article

Sigmund, J, Pavlidis, D, Hartnagel, HL et al. (2006). Nonstoichiometric growth and cluster formation in low temperature grown GaAsSb for terahertz-applications . JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B, 24(3), 1556-1558. 10.1116/1.2190677

cited authors

  • Sigmund, J; Pavlidis, D; Hartnagel, HL; Benker, N; Fuess, H

authors

abstract

  • Nonstoichiometric low-temperature grown (LTG) Ga As0.6 Sb0.4 is epitaxially grown by molecular beam epitaxy on a lattice mismatched Al0.77 In0.23 As buffer layer. Ex situ annealing leads to an increase in the wafer sheet resistivity. Values as high as 1.7× 108 sq were measured. By high resolution transmission electron microscopy, clusters were observed in LTG-Ga As0.6 Sb0.4 after annealing, some of them attached to dislocation lines. Moreover, in a 600 °C annealed sample, the clusters have two different crystal structures and a spread in cluster size is present from an early formation state up to a diameter of 12.5 nm. Hence, the strain surrounding the clusters is not uniform, which leads to an asymmetry of the x-ray diffraction (XRD) peak. In addition to an increased peak asymmetry with increasing annealing temperature, the XRD peak is shifted towards higher 2θ values, resulting in a lattice constant shift of 0.24%. This lattice constant shift is due to a strain relaxation process by forming clusters. © 2006 American Vacuum Society.

publication date

  • May 1, 2006

published in

Digital Object Identifier (DOI)

start page

  • 1556

end page

  • 1558

volume

  • 24

issue

  • 3