Electrical Properties of LiNbO 3 Thin Films by RF Magnetron Sputtering and Bias Sputtering

C-axis-oriented LiNbO3 thin films were prepared on Pt(111)/ SiO2 /Si substrates by rf magnetron sputtering. The LiNbO3 films grown showed pyroelectricity and piezoelectricity. The pyroelectric coefficient of the film was 71×10-6 C/(m2K) , which was 86% of the value of a LiNbO3 bulk crystal. The surface acoustic wave (SAW) velocity measured was 3980m/s. In order to control the polarization, bias sputtering was applied. When bias voltage was applied to the substrates during film growth, polarization reversal was observed. From these experimental results, it was found that bias sputtering effectively controls the polarization of LiNbO3 films.