| abstract |
A method for manufacturing a flexural plate wave sensor includes the steps of depositing an etch-stop layer (34) over a substrate (32), depositing a membrane layer (36) over the etch stop layer, depositing a piezoelectric layer (38) over the membrane layer, forming a first transducer (44) on the piezoelectric layer and forming a second transducer (48) on the piezoelectric layer, spaced from the first transducer. The method further includes the steps of etching a cavity (52) through the substrate, the cavity having substantially parallel interior walls (54a, 54b), removing the portion of the etch stop layer between the cavity and the membrane layer to expose a portion (53) of the membrane layer, and depositing an absorptive coating (56) on the exposed portion of the membrane layer. |