Elastic wave device and manufacturing method thereof

An elastic wave device comprising:

• a piezoelectric substrate;
• and
• an IDT electrode provided on the piezoelectric substrate;
• wherein
• the IDT electrode includes a first busbar, a second busbar separated from the first busbar, a plurality of first electrode fingers each including one end connected to the first busbar, and a plurality of second electrode fingers each including one end connected to the second busbar;
• the plurality of first electrode fingers and the plurality of second electrode fingers are interdigitated with each other, a portion in which the first electrode fingers and the second electrode fingers overlap with each other in an elastic wave propagation direction is defined as an intersection region, the intersection region includes, in a direction in which the first and second electrode fingers extend, a center region located on a central portion and first and second edge regions respectively disposed on both sides of the center region;
• in the first and second edge regions, recess portions are provided on the piezoelectric substrate, the first and second electrode fingers are provided in the recess portions, and are disposed on the piezoelectric substrate in the recess portions;
• and
• where an acoustic velocity of elastic waves in the center region is represented by V1, an acoustic velocity of elastic waves in the first and second edge regions is represented by V2, and an acoustic velocity of elastic waves in regions on sides of the first and second edge regions opposite from the center region is represented by V3, V3>V1>V2 is satisfied.