The influence of Sb as a surfactant during the growth of GaN-rich GaNAs alloys, through the addition of triethyl antimony (TESb), was determined. Both the absolute growth rate and As content of the film decreased with TESb mole fraction. Atomic force microscopy observations revealed that a small amount of Sb did not significantly change the surface morphology, whereas a high TESb mole fraction led to a step-bunched surface with atomically flat terraces. No Sb incorporation was detected in the films by electron probe microanalysis. Surface-segregated Sb was detected by Xray photoelectron spectroscopy with the surface concentration increasing with TESb flow rate. (C) 2004 Elsevier B.V. All rights reserved.