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Oxidation of the GaAs semiconductor at the Al2O3/GaAs junction

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Author

  • Marjukka Tuominen
  • Muhammad Yasir
  • Jouko Lang
  • Johnny Dahl
  • Mikhail Kuzmin
  • Jaakko Makela
  • Marko Punkkinen
  • Pekka Laukkanen
  • Kalevi Kokko
  • Karina Schulte
  • Risto Punkkinen
  • Ville-Markus Korpijarvi
  • Ville Polojarvi
  • Mircea Guina
Show all

Summary, in English

Atomic-scale understanding and processing of the oxidation of III-V compound-semiconductor surfaces are essential for developing materials for various devices (e.g., transistors, solar cells, and light emitting diodes). The oxidation-induced defect-rich phases at the interfaces of oxide/III-V junctions significantly affect the electrical performance of devices. In this study, a method to control the GaAs oxidation and interfacial defect density at the prototypical Al2O3/GaAs junction grown via atomic layer deposition (ALD) is demonstrated. Namely, pre-oxidation of GaAs(100) with an In-induced c(8 x 2) surface reconstruction, leading to a crystalline c(4 x 2)-O interface oxide before ALD of Al2O3, decreases band-gap defect density at the Al2O3/GaAs interface. Concomitantly, X-ray photoelectron spectroscopy (XPS) from these Al2O3/GaAs interfaces shows that the high oxidation state of Ga (Ga2O3 type) decreases, and the corresponding In2O3 type phase forms when employing the c(4 x 2)-O interface layer. Detailed synchrotron-radiation XPS of the counterpart c(4 x 2)-O oxide of InAs(100) has been utilized to elucidate the atomic structure of the useful c(4 x 2)-O interface layer and its oxidation process. The spectral analysis reveals that three different oxygen sites, five oxidation-induced group-III atomic sites with core-level shifts between -0.2 eV and +1.0 eV, and hardly any oxygen-induced changes at the As sites form during the oxidation. These results, discussed within the current atomic model of the c(4 x 2)-O interface, provide insight into the atomic structures of oxide/III-V interfaces and a way to control the semiconductor oxidation.

Department/s

Publishing year

2015

Language

English

Pages

7060-7066

Publication/Series

Physical Chemistry Chemical Physics

Volume

17

Issue

10

Document type

Journal article

Publisher

Royal Society of Chemistry

Topic

  • Physical Sciences
  • Natural Sciences

Status

Published

ISBN/ISSN/Other

  • ISSN: 1463-9084