Requirements for Piezoelectric Thin Film Applications to Radio Frequency Acoustic Wave Devices

Abstract

This paper discusses the requirements for piezoelectric thin film applications to radio frequency (RF) surface and bulk acoustic wave (SAW/BAW) devices. First, we survey the basic properties of RF SAW/BAW devices. We then discuss how device performances depend on the acoustic and piezoelectric properties of the piezoelectric thin films. Next, we discuss the effects of crystal grains and their boundaries within the thin films, and show how the binding strength of crystal grains affects the excitation and propagation of acoustic waves. Finally, we present basic design and characterization procedures for an SAW transversal filter employing an AlN/diamond structure.

Keywords:

• SAW
• BAW
• piezoelectric thin film
• AlN
• diamond

Acknowledgments

The authors thank their present and former lab members of Chiba University for their dedication to the work.