The oxide semiconductor ZnO is of high interest for electrooptical applications due to its direct and wide band gap in the UV region. We present our results on pulsed laser deposition growth of ZnO on GaN-buffered Al(2)O(3) substrates. Using in-situ reflection high energy electron diffraction, intensity oscillations were recorded and used to apply the technique of interval deposition. A significant improvement of structural thin film quality was achieved due to the expansion of the high quality from the first layers to the whole film thickness. (C) 2011 Elsevier B.V. All rights reserved.