We investigated the effect of adding Sb in 1-mu m-thick InGaAsN layers grown by solid source molecular beam epitaxy (MBE) method on InP substrates. Secondary ion mass spectroscopy (SIMS) analysis of the InGaAsSbN layer showed that both the nitrogen and the Sb concentration are uniform in the growth direction. The X-ray rocking curve (XRC) of InGaAsSbN was narrower than that of the InGaAsN layer, which suggests that adding Sb improved the crystallographic quality of the thick InGaAsN layer. The surface morphology of the thick InGaAsSbN layer was as smooth as that of the lattice-matched InGaAs layer, while the surface of the thick InGaAsN layer was rough. These results indicate that the crystalline quality of thick InGaAsN layer can be improved by adding Sb. The photoluminescence (PL) peak wavelength became longer by adding Sb, but the PL intensity decreased. This is supposed to be due to the sensitivity of PL intensity to the growth condition. (c) 2006 Elsevier B.V. All rights reserved.