Acoustic wave device and method for fabricating the same

A method for fabricating an acoustic wave device, the method comprising the steps of:

• forming an insulating material layer on a piezoelectric substrate;
• forming a patterned photoresist on the insulating material layer, patterning the insulating material layer, and forming a piezoelectric-substrate exposed depression corresponding to a region where an interdigital transducer electrode is to be formed on a first insulator layer composed of the insulating material layer;
• depositing a metallic material on the piezoelectric substrate to form the interdigital transducer electrode in the piezoelectric-substrate exposed depression such that the interdigital transducer electrode is thinner than the first insulator layer and coating the photoresist with a metallic film;
• removing the photoresist and the metallic layer on the photoresist;
• and
• depositing a second insulator layer so as to cover the interdigital transducer electrode and the first insulator layer.