Differences in sample quality and nitrogen incorporation in InGaAsN quantum well samples grown by metal-organic vapor phase epitaxy using either H-2 or N-2 as the carrier gas are studied by several ex situ methods. The nitrogen incorporation increases while the indium content and the growth rate of the quantum wells decrease when using N-2 as the carrier gas instead of H-2. Also, the hydrogen incorporation into the quantum well is reduced by one order of magnitude. In addition, the in situ reflectance monitoring technique is used to monitor the material quality of the sample and the slope of the reflectance change is shown to be linearly dependent on the quantum well nitrogen content. (c) 2006 Elsevier B.V. All rights reserved.