Strong Correlation Between Oxygen Donor and Near-Surface Electron Accumulation in Undoped and Mg-Doped In-Polar InN Films

Abstract

A strong electron accumulation was observed in near-surface regions of undoped and Mg-doped In-polar InN films by analyzing the valence band maximum dependent on the take-off angles. The amount of oxygen correlated with electron carrier concentration drastically increased in both near-surface regions, suggesting that the oxygen atoms in both near-surface regions act as donors. For Mg-doped InN, the amount of oxygen in the near-surface region was almost twice that of undoped InN, indicating that much more oxygen atoms in the near-surface region were incorporated to compensate the Mg acceptors to contribute to the electron accumulation surface layer.

Investigation of the Effect of Oxygen on the Near-Surface Electron Accumulation in Nonpolar m-Plane (101̄0) InN Film by Hard X-ray Photoelectron Spectroscopy

“…For the spectra, fitting were performed using the Voigt function after subtracting the Shirley background. 20) The O 1s spectrum of the m-plane InN collected at TOA of 79 is shown in Fig. 3(a).…”

“…The position of the valence band maximum (VBM) was determined by extrapolating a linear fit to the leading edge of the valence-band spectrum to the background level. 20,25,26) Japanese Journal of Applied Physics 52 (2013) 08JD01 08JD01-1 # 2013 The Japan Society of Applied Physics REGULAR PAPER http://dx.doi.org/10.7567/JJAP.52.08JD01…”

“…19) Strong correlation between oxygen donor and near-surface electron accumulation in the undoped and Mg-doped In-polar InN films has been reported. 20) Therefore, the knowledge of the effect of the incorporated impurity oxygen on the electronic structure of as-grown m-plane InN is of crucial importance not only for the fundamental understanding of the material, but also for technological applications. Hard X-ray photoelectron spectroscopy (HXPES), which exhibits larger probing depths, is widely used for the investigation of the bulk electronic structure of materials.…”

Electrical characterization of atomic layer deposited Al2O3/InN interfaces

“…5,7,8 The presence of surface electron accumulation layer also makes it difficult to use conventional methods for determining the bulk carrier properties in p-type InN. 6,10 By optimizing the growth condition and by p-type doping, surface electron concentration at surface has been reduced; 6,11,12 however, the concentration is still high for device applications.…”