The composition, strain and surface morphology of (0001)InGaN layers are investigated as a function of growth temperature (460-645 degrees C) and impinging In flux. Three different growth regimes: nitrogen-rich, metal-rich and intermediate metal-rich, are clearly identified and found to be in correlation with surface morphology and strain relaxation. Best epilayers' quality is obtained when growing under intermediate metal-rich conditions, with 1-2 monolayers thick In ad-coverage. For a given In flux, the In incorporation decreases with increasing growth temperature due to InN thermal decomposition that follows an Arrhenius behavior with 1.84 +/- 0.12 eV activation energy. (C) 2012 Elsevier B.V. All rights reserved.