MG-DOPED P-TYPE GAN GROWN BY REACTIVE MOLECULAR-BEAM EPITAXY

P-type conductivity in as-grown Mg-doped GaN films grown by reactive m olecular beam epitaxy technique which employs ammonia as the nitrogen source is reported. Doping level and mobility of the films up to 4.5 X 10(17) cm(-3) and 6 cm(2)/V s, respectively, have been achieved witho ut any post-growth treatments. The photoluminescence spectra show both band edge and high-related emission at room temperature. Neither anne aling in nitrogen ambient furnace nor rapid thermal annealing was foun d to have any discernible influence on the electrical properties of th e films. More than 6% of incorporated Mg was activated For the samples with relatively low Mg concentration. The measured activation energy of Mg acceptor was 160+/-5 meV. (C) 1996 American Institute of Physics .