For the growth of AlN single crystal with large diameter and low dislocation density on SiC substrate by physical vapor transport (PVT), a dislocation blocking buffer layer (DBBL) has been simply developed by optimizing the AlN growth parameters such as temperature gradient (Delta T), substrate temperature (T-sub), and N-2 partial pressure (P-N2) at the initial growth stage. Increase in Delta T resulted in the formation of an abrupt AlN/SiC interface due to the suppression of inhomogeneous thermal decomposition at the interface and the subsequent AlN unstable island growth. The well-defined AlN/SiC interface played an important role in controlling the two kinds of different AlN growth mode in-situ as functions of T-sub and P-N2. One is a continuous step-flow growth mode, and the other is a discontinuous platelet-like growth. The discontinuous AlN layer, consisting of thin AlN platelets and air-gaps inserted between the two adjacent platelets, acted as the DBBL. By introducing the DBBL at the initial growth stage, followed by the step-flow growth, continuous AlN layer with dislocation density of 1.7 x 10(6) cm(-2) was achieved at a total growth thickness of 60 mu m, which is two orders of magnitude lower than the previously reported value. (C) 2017 Elsevier B.V. All rights reserved.