Abstract
Electron accumulation at the oxidized surface of In- and N-polarity indium nitride is shown to exhibit no dependence on the growth conditions (varied from In- to N-rich), revealing the surface Fermi level to be pinned 1.4 +/- 0.1 eV above the valence band maximum for all cases. This is in contrast to the interpretation of recent multiple-field Hall effect measurements, which suggested almost an order of magnitude increase in the sheet density of the accumulation layer upon moving from In-rich to N-rich growth conditions, and sample thickness dependent single-field Hall effect measurements which suggested different surface sheet densities for In- and N-polarity samples. However, an increase in the electron density approaching the InN/GaN (buffer layer) interface was not considered in the analysis of these Hall effect measurements, and this is invoked here to reconcile the constant surface Fermi level with the variations in "excess" sheet density observed in the previous Hall effect studies.
Original language | English |
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Pages (from-to) | 103703 |
Number of pages | 5 |
Journal | Journal of Applied Physics |
Volume | 104 |
Issue number | 10 |
DOIs | |
Publication status | Published - 15 Nov 2008 |
Keywords
- buffer layers
- Fermi level
- gallium compounds
- Hall effect
- III-V semiconductors
- indium compounds
- semiconductor growth
- semiconductor thin films
- valence bands
- wide band gap semiconductors
- MOLECULAR-BEAM EPITAXY
- MULTIPLE CARRIER TRANSPORT
- INDIUM NITRIDE
- BAND-GAP
- SEMICONDUCTORS
- ACCUMULATION