Abnormal residual stress state in ZnO films synthesized by planar magnetron sputtering system with two facing targets

The structure and residual stresses of ZnO films synthesized by a planar ma gnetron sputtering system with two facing targets were investigated by X-ra y diffraction. ZnO films were deposited onto a sheet of Coming 7059 glass. The X-ray diffraction pattern shows that the film has high {00.1} orientati on. Residual strains were measured on various diffraction lines that appear at special angles psi from the surface normal. The strains taken from posi tive and negative psi differed from each other. This behavior is deduced fr om the existence of a shear stress component in a cross-section of the film . The magnitude of the shear stress increased with increasing current densi ty of the Zn target as well as with decreasing argon gas pressure. (C) 1999 Elsevier Science S.A. All rights reserved.