Multilayer devices comprised of piezoceramic thin films on dielectric substrates

Nano-structures for telecommunications and sensing applications will continue to become increasingly more intricate [1]. They will operate at higher frequencies, and will incorporate various processing and actuation modalities in novel and very compact architectures. One of these modalities is anisotropic acoustics. To facilitate the progress of more sophisticated integrated structures, this paper discusses relevant bulk acoustic wave parameters and values for a variety of anisotropic materials considered most likely to play important parts as multi-mode substrates for piezoceramic drivers. The materials fall into the cubic (e.g., Si, Ge, C(d), and GaAs), tetragonal (e.g., single-crystal ferroelectrics), hexagonal (e.g., AIN, GaN, InN), and trigonal (e.g., Al2O3, LiNbO3, langasite and its isomorphs) crystal classes. The combination of cost-effective piezoceramic thin film epilayers with highly anisotropic substrates increases the gamut of multilayer device capabilities. Circuit descriptions are also provided.