X-ray photoelectron spectroscopy evaluation on surface chemical states of GaN, InGaN and AIGaN heteroepitaxial thin films grown on sapphire by MOCVD

K. Li*, A. T.S. Wee, J. Lin, Z. C. Feng, S. J. Chua

*Corresponding author for this work

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5 Scopus citations

Abstract

The surface chemical states of MOCVD grown GaN, A1GaN and InGaN, and the influence of different dopants have been studied with x-ray photoelectron spectroscopy (XPS). The results show that for most of the samples the N ls peak can be fitted with a dominant GaN peak at the binding energy of 397.2 ± 0.2 eV and a small N-H peak at the binding energy of 398.5 ± 0.2 eV, while Ga 3d can be deconvoluted into three peaks, i.e., elemental Ga at 18.5 ± 0.1 eV, GaN at 19.7 ± 0.1 eV, and Ga2O3 at 20.4±0.1 eV. Si-doping appears to have small influence on the surface chemical states of GaN. Compared with Sidoping, the influence of Mg-doping appears to be larger. In addition to a change in the component intensities, Mg-doping also causes the N ls and Ga 3d peaks to broaden. The ternary AlxGal-xN (x ∼0.025) sample shows aluminum surface segregation, while the undoped InxGal-xN (x ∼0.12) shows indium surface deficiency.

Original languageEnglish (US)
Pages (from-to)303-308
Number of pages6
JournalMaterials Research Society Symposium - Proceedings
Volume618
StatePublished - 2000
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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