GaInNAs/GaAs quantum dots (QDs) were grown by solid-source molecular beam epitaxy equipped with a radio frequency nitrogen (N-2) plasma source for the first time. High-density (similar to10(10) cm(-2)) GaInNAs QDs with small sizes (similar to30nm) were achieved. Reflection high-energy electron diffraction observation revealed that the formation of GaInNAs QDs follows the Stranski-Krastanow growth mode. The evolution of GaInNAs QDs was investigated by atomic force microscopy, and the amount of GaInNAs coverage was found to have a significant effect on the dot density, average size and aspect ratio. Low temperature (5 K) photoluminescence measurement on the GaInNAs QDs showed that the incorporation of N into InGaAs effectively reduced the emission energy, and there is an optimal amount of GaInNAs coverage, which will produce QDs with maximum luminescence intensity. (C) 2002 Published by Elsevier Science B.V.