Surface band bending at n-type and p-type InN by Auger Electron Spectroscopy

Volker Cimalla 2Merten Niebelschütz 2Gernot Ecke 2Oliver Ambacher Ruediger Goldhahn 3Hai Lu 1William J. Schaff 1

1. Cornell University, 425 Philips Hall, Ithaca, NY 14853, United States
2. Technical University Ilmenau, Center of Micro- and Nanotechnologies (ZMN), Gustav-Kirchhoff-Str. 7, Ilmenau 98693, Germany
3. Technische Universität Ilmenau, Institut für Physik, PF 100565, Ilmenau 98684, Germany

Abstract

Thin films of InN show high n-type conductivity, for which the origin is not completely identified up to date. InN layers with carrier concentrations down to 1017 cm-3 have been prepared, however, no p-type InN could be demonstrated. Electron accumulation at the surface was verified on air [1], and on clean InN surfaces in ultrahigh vacuum [2]. It was explained as an intrinsic property of InN layers ascribed to its band structure [2]. In a previous work [3] we showed by Auger electron spectroscopy (AES) depth profiling and simultaneous conductivity measurements the correlation between the oxygen content and the electron accumulation. In this work we extend this study by analyzing the peak energy shift in AES on both undoped and Mg-doped InN. The position of the Auger peaks is sensitive to the position of the Fermi level [4]. This capability was used to obtain information about the type of conductivity and the band bending. On all InN surfaces a strong increase of the resistivity within the first 5 nm confirms the existence of a highly conductive n-type surface layer. A strong Auger peak shift of about 2 eV was observed due to the formation of a wide band gap In2O3. After reaching equilibrium of the peak shift after the removal of about 50 nm a difference of 0.3 eV was observed between undoped and Mg-doped InN. Consequently, Mg-doped InN layers have indeed p-type conduction; however, the high n-type surface conductivity is overlaying it and the InN layer appears to be n-type.

[1] H. Lu, W.J. Schaff, et al, Appl. Phys. Lett. 82, 1736 (2003)

[2] I. Mahboob, T.D. Veal, et al, Phys. Rev. B 69, 201307 (R) (2004).

[3] V. Cimalla, et al, phys. stat. sol (c) 2,

[4] R. Kosiba, Thesis, Technical University Ilmenau, 2004

 

Related papers
  1. In-vacancies in Si-doped InN
  2. Irradiation-induced defects in InN and GaN studied with positron annihilation
  3. Study of Si doped AlGaN by synchrotron radiation x-ray microprobe techniques
  4. Compositional modulation in the InxGa1-xN layers; relation to their optical properties
  5. Recombination processes with and without momentum conservation in degenerate InN
  6. Optical properties of InN films and the influence of surface contaminations
  7. Conduction band anisotropy of InN and GaN studied by synchrotron ellipsometry
  8. Acceptor states in photluminescence of n-InN
  9. Band Structure and Properties of InN and In-rich In1-xGaxN Alloys
  10. Quantized Electron Accumulation, Inversion Layers and Fermi Level-Stabilization in Indium Nitride
  11. Valence band structure of InN from x-ray photoemission studies
  12. InN explained within chemical trends
  13. Resonant tunneling and intersubband absorption in AlN-GaN-superlattices
  14. AlGaN/GaN based optical and electrical sensors
  15. Alignment of SiC quantum dots on silicon substrates
  16. 3C-SiC:Ge alloys grown on Si (111) substrates by solid source MBE
  17. Kinetic Monte Carlo simulation of SiC nucleation on Si(111)
  18. The role of Ge predeposition temperature in the epitaxy of SiC on Silicon
  19. Studies on sub-band gap absorption in AlGaN photoconductors and solar-blind photodetectors

Presentation: oral at E-MRS Fall Meeting 2005, Symposium A, by Volker Cimalla
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-05-20 13:06
Revised:   2009-06-07 00:44