Thermal diffusion of nitrogen into ZnO film deposited on InN/sapphire substrate by metal organic chemical vapor deposition

ZnO film with high crystal quality was prepared on InN/sapphire substrate by metal organic chemical vapor deposition. The diffusion of nitrogen (N) into ZnO film was investigated via Auger electron spectroscopy (AES), x-ray photoelectron spectroscopy (XPS), and low-temperature photoluminescence (LT-PL). AES revealed that some N atoms out-diffused into ZnO film after a rapid thermal annealing (RTA) process, while most of the In atoms remained in InN layers, which was confirmed by XPS. LT-PL spectra at 10K further confirmed that N atoms diffused into the upper ZnO film and acted as acceptors after RTA. It might be an attractive way to obtain high-quality p-type ZnO: N on InN films by this thermal diffusion doping technique. (C) 2011 American Institute of Physics. [doi:10.1063/1.3665203]