Acoustic wave device

An acoustic wave device, comprising:

• a first acoustic wave resonator including:
• a piezoelectric substrate;
• and
• a first IDT electrode including a plurality of electrode fingers located on the piezoelectric substrate;
• and
• a second acoustic wave resonator sharing the piezoelectric substrate with the first acoustic wave resonator and including:
• a second IDT electrode including a plurality of electrode fingers located on the piezoelectric substrate;
• wherein
• an area in the first IDT electrode where adjacent ones of the plurality of electrode fingers overlap each other when viewed in a direction perpendicular to a direction in which the plurality of electrode fingers extend is a first apodization area;
• the first apodization area includes a first center area, and a first edge area and a second edge area with the first center area therebetween in the direction in which the plurality of electrode fingers extend;
• an area in the second IDT electrode where adjacent ones of the plurality of electrode fingers overlap each other when viewed in a direction perpendicular to the direction in which the plurality of electrode fingers extend is a second apodization area;
• the second apodization area includes a second center area, and a third edge area and a fourth edge area with the second center area therebetween in the direction in which the plurality of electrode fingers extend;
• the acoustic wave device further comprises:
• at least one first mass-adding film located in at least one of the first edge area and the second edge area, and overlapping the plurality of electrode fingers of the first IDT electrode in a plan view;
• and
• at least one second mass-adding film located in at least one of the third edge area and the fourth edge area, and overlapping the plurality of electrode fingers of the second IDT electrode in a plan view;
• wherein
• a thickness of the plurality of electrode fingers of the second IDT electrode is smaller than a thickness of the plurality of electrode fingers of the first IDT electrode;
• a thickness of the at least one first mass-adding film is equal to a thickness of the at least one second mass-adding film;
• and
• a width of the plurality of electrode fingers of the second IDT electrode at a portion overlapping the at least one second mass-adding film in a plan view is smaller than a width of the plurality of electrode fingers of the second IDT electrode in the second center area.