Film growth of c-axis tilted ScAlN on the sapphire substrate for SAW devices

Abstract

Recently, it was shown that heavily doped AlN film possess the high piezoelectricity by Akiyama et al [1]. On the other hand, SAW devices were widely used as filters and sensors. Among them, SAW in ScAlN film is attracting a lot of attention because this SAW devices have high electromechanical coupling coefficient K2. We analyzed the K2 value in Sc _0.4 Al _0.6 N was increased by c-axis tilted angle θ becoming bigger [2]. In this study, changing the angle of c-axis tilted ScAlN films, we have tried to improve the K2 value of SAWs in c-axis tilted ScAlN/R-sapphire.