Composite layer used e.g. for thin film bulk acoustic wave resonators, includes silicon oxide layer between piezoelectric layer and diamond-like carbon layer

摘要

A composite layer includes a piezoelectric layer (P) and a DLC (diamond-like carbon) layer (C), in which an SiO2 layer (S) is located between the piezoelectric layer and the DLC layer to increase the overall adhesion of the layers in the composite, the SiO2 layer having relatively low thickness compared with the other layers. An Independent claim is included for the preparation of a composite layer as above in which a DLC layer is deposited on the SiO2 layer by a PECVD process.