A combined modeling and experimental analysis of GaN/AlGaN deposition in the commercial vertical high-speed rotating-disk reactors produced by EMCORE is performed with reference to the optimization of the growth rate and layer composition uniformity. It is demonstrated that for both GaN and AlGaN layers the non-uniformity of 2-3% can be achieved for the growth on 2 in wafers, and the optimized growth recipe can be used for the deposition on 3 in and even 4 in wafers with the non-uniformity about 5%. Modeling results are in good agreement with the experimental data. (C) 2003 Elsevier B.V. All rights reserved.