Influence of the substrate on the structural properties of sputter-deposited ZnO films

We have deposited ZnO films on various substrates using the r.f. magnetron sputtering method. X-ray diffraction and scanning electron microscopy coincidentally revealed that the larger grain size and the higher crystallinity were attained when the ZnO films were deposited on sapphire substrates, compared to the films on Si substrates. The XRD analysis revealed that the c-axis lattice constant decreased and increased, respectively, by thermal annealing for the ZnO films deposited on Si and sapphire substrates. Atomic force microscopy indicated that the surface roughness was higher for the films deposited on the sapphire substrates. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.