[21a-P06-1~4] 1.6 Ultrasonics

[21a-P06-4] Fabrication of c-axis tilted ScAlN film/Si substrate layered structure for SAW devices

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

Keywords:ScAlN film, SAW, Sputtering deposition

ScAlN films are being actively researched for elastic wave device because of their strong piezoelectricity. Recently, ScAlN film/high BAW velocity substrate (e.g. diamond and SiC) structure was reported to have a high electromechanical coupling coefficient K² of surface acoustic wave (SAW) devices, whereas they have cost disadvantages. Si substrate is an inexpensive substrate widely used in integrated circuits. We have previously shown that in the crystal class (6mm) including ZnO and AlN, K² values increases with their c-axis tilt. In this study, we propose SAW devices with high K² using c-axis tilted ScAlN film/Si substrate layered structure, and introduce their fabrication method via RF magnetron sputtering.