High-performance surface acoustic wave resonators in the 1 to 3 GHz range using a ScAlN/6H-SiC structure

This paper describes application of Sc-doped AlN (ScAlN) to wideband SAW devices in the 1 to 3 GHz range. First, it is shown theoretically that large SAW velocity and electromechanical coupling factor are simultaneously achievable when the ScAlN film is combined with a base substrate with extremely high acoustic wave velocities, such as diamond and SiC. Next, SAW delay lines are fabricated on the ScAlN/6H-SiC structure, and reasonable agreement between the theory and experiment is obtained. Finally, one-port SAW resonators are fabricated on the structure, and it is shown that high-performance is achievable in the 1 to 3 GHz range by use of the structure.