Characterization of ferroelectric LiNbO3thin film prepared by sol-gel process

Microstructures and optical properties of ferroelectric LiNbO3 thin films on Si and sapphire substrates are investigated. For the films on Si substrates, polycrystalline films with smooth surface were obtained. Most of voids were found to be formed at the interface between the film and Si substrate. Highly (001) and (012) oriented films can be fabricated on sapphire substrates. Decrease in the gap energy as increasing the annealing temperature was discussed in conjuction with the grain growth of the films.