The calculation of electrical parameters of film bulk acoustic wave resonators from vibrations of layered piezoelectric structures

Abstract

Film bulk acoustic wave resonators (FBARs) are new generation of piezoelectric resonators with higher frequencies and manufacturing process compatible with existing semiconductor technology. With the successful development of FBAR products for wireless communication applications, the FBAR technology are being extensively studied for new technology, products, and applications. Due to the sophistication of the FBAR technology and demands for precision products, it is natural to make use of the full analysis of acoustic waves propagating in the FBAR structures for design and calculating electrical parameters before the fabrication. The analytical approach based on wave propagation in layered structures will be important in improving design and conceiving new products. The introduction of material viscosity will enable the formulation and calculation of FBAR properties with solutions of wave propagation. Current formulation based on one-dimensional approach can be easily extended to the finite structure of smaller FBARs for improved analysis and design. The formulation can also be extended to work with numerical methods which are widely adopted in the FBAR development.