The diffusion of indium in single-crystal ZnO was studied by using an ion implantation technique (accelerating voltage of 170keV and dose of 1016/cm2) at 750 to 850C. The indium profiles have a characteristic tail with a constant concentration region due to the Fermi-level effect on the diffusion. The simulated profiles of indium diffusion in ZnO fitted well with the experimentally determined profiles. Possible models for indium diffusion, based upon an interstitialcy mechanism or a vacancy mechanism, were proposed.

Analysis of Indium Diffusion Profiles Based on the Fermi-Level Effect in Single-Crystal Zinc Oxide. Nakagawa, T., Matsumoto, K., Sakaguchi, I., Uematsu, M., Haneda, H., Ohashi, N.: Japanese Journal of Applied Physics, 2008, 47[10], 7848-50