To investigate mask effects on InGaN selective area metal-organic vapor-phase epitaxy (SA-MOVPE), in-plane thickness profiles of InGaN were investigated with various indium contents covering between InN and GaN. A numerical simulation employing vapor-phase diffusion (VPD) model was also carried out for the quantitative analysis of VPD effect. At the growth temperatures of 650 and 700 degrees C, the indium content in the vapor phase and that in the solid phase exhibited almost linear relationship, suggesting that the growth of InGaN can be approximated as the superposition of the growth of InN and GaN. The effective vapor-phase diffusion length D/k(s) of GaN was much smaller than InN. The profile of the InGaN growth rate in the selective area became more gradual as the solid indium content increased, and the trend seems to be the linear interpolation between the profiles of GaN and InN. However, as the indium content increases, deposition selectivity between mask and crystal surface become degenerated, and the VPD effect was almost canceled when the solid indium content exceeds 0.5. Although further improvement on the growth conditions is necessary to improve selectivity, basic information for the design of the SA-MOVPE of InGaN has been obtained, which will contribute to InGaN-based monolithically integrated multi-wavelength devices. (C) 2008 Elsevier B.V. All rights reserved.