Excitation of acoustic waves at the interface between lithium niobate and silicon plates

We discuss the fabrication and characterization of IAW resonators made by indirect bonding of lithium niobate onto silicon. In our fabrication process, IDTs are first patterned over the surface of a Y-cut lithium niobate wafer. A thin layer of SU-8trade photo-resist is then spun over the IDTs and lithium niobate to a final thickness below one micron. The SU-8trade covered lithium niobate wafer is then bonded to a silicon wafer using a wafer bonding machine. Measurements of resonators are presented and compared with theoretical computations based on our periodic finite element/boundary element code allows for explaining the actual operation of the device.