SURFACE ELASTIC WAVE RESONATOR, FILTER, DUPLEXER, AND COMMUNICATION APPARATUS

摘要

PURPOSE: A surface elastic wave resonator is provided to be capable of preventing a damage of electrode pattern and preventing a electrode of required part of the electrode pattern from etching. CONSTITUTION: A surface elastic wave resonator(1) is arranged to generate a shear horizontal wave. An IDT(interdigital transducer)(3) includes a electrode film made up of metal having W or Ta and a first AL thin film formed on the electrode film. A surface elastic wave filter includes the surface elastic wave resonator. A duplexer and communication apparatus include the surface elastic wave filter. A method for manufacturing the surface elastic wave resonator comprises the steps of: providing LiNbO3 substrate of Y-cut x-propagation materials; forming a electrode film made up of metal having Ta or W on the substrate; forming a first AL thin film on the electrode film; forming a resist film on the first AL thin film; and performing a reactive ion etching of the electrode film. Thereby, it is possible to prevent a damage of electrode pattern and to prevent a electrode of required part of the electrode pattern from etching.