Temperature-Compensated High-Frequency Surface Acoustic Wave Device

We report high-frequency surface acoustic wave (SAW) devices with excellent temperature stability using a layered structure consisting of single-crystal LiNbO3 thin film on SiO2/LiNbO3 substrate. SAW devices with a wavelength of 2 mu m have been fabricated and several wave modes ranging from similar to 1.5 to 2.1 GHz have been obtained. With the SiO2 interlayer providing the temperature compensation and the top single-crystal Z-cut LiNbO3 piezoelectric thin film for acoustic wave excitation, the fabricated SAW devices exhibit excellent temperature coefficients of frequency. Theoretical calculations are presented to elucidate temperature compensation of the proposed layered structure.