Acoustic wave device and electronic apparatus including same

An acoustic wave device comprising:

• a piezoelectric substrate having an upper surface;
• an interdigital transducer (IDT) electrode disposed above the upper surface of the piezoelectric substrate, the IDT electrode including a plurality of electrode fingers configured to excite a main acoustic wave;
• a first dielectric film made of oxide disposed above the upper surface of the piezoelectric substrate, the first dielectric film covering the plurality of electrode fingers;
• and
• a second dielectric film made of non-oxide disposed on upper surfaces of the plurality of electrode fingers and between the first dielectric film and each of the plurality of electrode fingers,
• wherein the first dielectric film contacts the upper surface of the piezoelectric substrate at a position between electrode fingers out of the plurality of electrode fingers adjacent to each other.