Study of in distribution on GaInSb:Al crystals by ion beam techniques

M. Streicher, V. Corregidor, N. Catarino, L. C. Alves, N. Franco, M. Fonseca, L. Martins, E. Alves, Eleani Maria da Costa, B. A. Dedavid

Research output: Contribution to journalConference articlepeer-review

4 Citations (Scopus)

Abstract

III-V ternary alloys semiconductor materials, in particular Ga1-xInxSb, are ideal candidates for device substrates because of the possibility to define the lattice constant as a function of the third element, indium. Aluminum, an isoelectric dopant for Ga and In, increases the carrier mobility in GaSb crystals and has influence over the concentration of native defects by passivating and/or compensating them. To understand the influence of Al on the distribution of indium in ternary alloys of Ga0.8In0.2Sb, pure and doped ingots were obtained with approximately 1020 atoms/cm3 of Al using a vertical Bridgman system. Analysis by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), particle induced X-ray emission (PIXE) and particle induced gamma ray emission (PIGE) were used to obtain information on the structure defects and chemical composition of the crystals. The doped ingots showed good structural homogeneity when compared with the undoped alloy, and they were free from cracks and micro cracks. All of the obtained ingots present precipitates, twins and grains with different concentrations of In. The small compositional variation observed in the doped ingots along the radial direction (measured by PIXE), may be related to the solid-liquid interface's quasi-equilibrium behavior. Regarding to the growth direction, it was observed that the undoped ingots exhibit a higher segregation phenomenon of the third element than the doped ingots. The obtained results indicate that aluminum influences the indium distribution in the ingots, thus ternary ingots with more homogeneous composition can be obtained and consequently electrical properties improved.

Original languageEnglish
Pages (from-to)278-282
Number of pages5
JournalNuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Volume371
DOIs
Publication statusPublished - 15 Mar 2016
Event22nd International Conference on Ion Beam Analysis (IBA) - Opatija, Croatia
Duration: 14 Jun 201519 Jun 2015

Keywords

  • Aluminum
  • Composition
  • PIGE
  • PIXE
  • Ternary alloy of GaInSb

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