[17p-Z13-1~8] 1.6 Ultrasonics

△ [17p-Z13-2] BAW and SAW Characteristics of (K,Na)NbO₃ Films Deposited by RF Sputtering

〇Kazuma Yoshizawa¹, Masashi Suzuki¹, Shoji Kakio¹, Yoshiharu Ito², Akinori Tateyama², Hiroshi Funakubo², Tsuyoshi Wakabayashi³, Kenji Shibata⁴ (1.Univ. of Yamanashi, 2.Tokyo Inst. of Technology, 3.Koike Co., Ltd., 4.SCIOCS Co., Ltd.)

Keywords:surface acoustic wave, highovertone bulk acoustic resonator, RF sputtering

For high performance surface acoustic wave filters and piezoelectric thin film resonators, piezoelectric materials with high electromechanical coupling coefficient (Kt) and low propagation loss are desired. In this report, we evaluated the bulk wave response of a thin-film resonator with a substrate (HBAR) using a (K,Na)NbO₃ (KNN) film prepared by RF sputtering. We also fabricated the input and output interdigital transducers on a KNN film, and evaluated the SAW propagation characteristics for comparing with hydrothermal-synthesis KNN films. As a result of the experiments, we obtained similar Kt and faster phase velocity than that of hydrothermal synthesis films.