[23p-D113-1~19] 1.6 Ultrasonics

△ [23p-D113-19] Numerical simulation of Rayleigh-mode SAW propagating in c-axis zigzag ScAlN film/silicon substrate layered structure

〇Takumi Tominaga¹, Shinji Takayanagi¹, Takahiko Yanagitani² (1.Doshisha Univ., 2.Waseda Univ.)

Keywords:SAW, ScAlN films, Silicon

SAW devices with a high frequency, high electromechanical coupling factor K², and high Q factor are required for filters and duplexers in smartphones for next-generation mobile networks. ScAlN films are important candidates for piezoelectric layers due to their high piezoelectricity. We have reported that the K² value of SAW propagating in the ScAlN film/silicon substrate structure increases due to the ScAlN film c-axis tilt. In this study, we performed a numerical simulation of SAW propagating in the c-axis zigzag ScAlN film/silicon substrate structure to further increase the K² values of SAW devices. As a result of SAW analysis, the maximum K² value of Rayleigh-mode SAW was 9.56%. This value is approximately 2.4 times the maximum K² of the c-axis tilted ScAlN film/silicon substrate structure. These results indicate that the c-axis zigzag ScAlN film/silicon substrate structure is suitable for Rayleigh-mode SAW devices with high electromechanical coupling factor.