The effect of energetic nitrogen ion bombardment during growth may have a deleterious effect on the material quality. To avoid the bombardment effect of energetic nitrogen ions, a modified mode for GaAsN growth using dispersive nitrogen is reported. High quality GaAsN epilayers and good GaAsN/GaAs interface were achieved using this growth mode. The results suggest that the surface of samples grown using dispersive nitrogen has fewer defects than those grown using direct nitrogen beam. The optical property of GaAsN samples grown using the dispersive nitrogen technique was found to improve, due to the lower ion bombardment effect. This growth technique is expected to be advantageous for growing high quality GaAsN materials for optoelectronic applications.