Growth of LiNbO3 films on single crystal sapphire substrates using pulsed laser deposition

We report on the epitaxial growth of LiNbO3 (11(2) over bar 0) films on sap phire (11(2) over bar 0) substrates using pulsed laser deposition. We have used a Li-enriched target of Li2NbO3 to compensate for the loss of Li at hi gh deposition temperatures of 600-800 degrees C, X-ray theta-2 theta scans reveal that the crystal orientation of our LiNbO3 films is very sensitive t o the deposition temperature and oxygen pressure. To obtain a single (11(2) over bar 0) orientation, we need to use a deposition temperature of 800 de grees C and an oxygen pressure of 10(-5) Torr. Otherwise, an extra (0001) o rientation of LiNbO3 always occurs. From a rocking curve of the (11(2) over bar 0) peak, we have measured a full width at half maximum of 0.3 degrees, implying that our LiNbO3 (11(2) over bar 0) film is highly oriented. The m easured dielectric constants of the LiNbO3 (0001) and (11(2) over bar 0) fi lms at 1 MHz are 80 and 70, respectively.