This article presents an investigation on the epitaxial growth of non-polar a-plane AlN thin films by low temperature sputtering using ZnO buffer layers. Prior to the deposition of the AlN films, epitaxial growth of a-plane ZnO thin films on r-plane sapphire substrates was performed by a metalorganic chemical vapor deposition (MOCVD). The effect of MOCVD growth conditions on surface morphology and crystallinity of ZnO epi-layer was examined to optimize the growth process of buffer layer. The resulting ZnO epi-layers were used as buffer layers to grow non-polar AlN by low temperature sputtering. The measurements of XRD 2theta/omega- and phi-scans indicate that the epitaxial relationship among AlN, ZnO and sapphire substrate is (11 (2) over bar0)(AlN)//(11 (2) over bar0)(ZnO)//(1 (1) over bar 02) and [1 (1) over bar 00](AlN)//[1 (1) over bar 00](ZnO)//[11 (2) over bar0](Al203). Cross-sectional transmission electron microscopy (XTEM) revealed that no reactive intermediate layers formed at the interfacial region between AlN film and ZnO buffer layer. The a-plane ZnO layers can be used as lattice matched templates for epitaxial growth of non-polar AlN by low temperature sputtering. (C) 2011 Elsevier B.V. All rights reserved.