The influence of AlN growth with a linear change of ammonia flux on the quality of AlN epilayers grown by low pressure metalorganic vapor phase epitaxy was studied, It was shown that by using this method it was possible to complete the coalescence of the grown AlN epilayer and eliminate pits from the surface as well as to prevent growth of nanocolumns. It was shown that decreasing ammonia flux has the most significant influence on the course of the coalescence process of the layer. The epilayers were analyzed using atomic force microscopy (AFM) to investigate their morphological properties and by high resolution X-ray diffraction (HRXRD) to study their structural properties. The etch pit density was examined by defect-selective etching. (C) 2014 Elsevier B.V. All rights reserved.