The deposition of lithium niobate (LiNbO3) films on sapphire substrates (001) and (110) using pulsed excimer-laser ablation has been investigated. The effect of several experimental parameters. Li/Nb ratio of the target, the substrate temperature, and the pressure and composition of the gas during the deposition, on the resulting film quality are examined. Under optimized conditions, epitaxial LiNbO3 films of high quality are deposited. The as-grown LiNbO3 films are sufficiently piezoelectric to fabricate surface acoustic wave (SAW) devices without poling. Rayleigh and Love-type waves are observed on the films and these waves show high velocities of propagation (5300 to 6600 m/s) and good temperature coefficients (-34 to -80 ppm/deg). The chemical composition, microstructure, crystallographic orientation, crystallinity, and SAW properties of the films are evaluated. © 1995 American Institute of Physics.
