Acoustic wave device and acoustic wave device manufacturing method

An acoustic wave device manufacturing method comprising:

• forming a film of a first intermediate layer on a principal surface of a support substrate including a first crystal axis;
• forming a film of a second intermediate layer on a principal surface of the first intermediate layer after the forming the film of the first intermediate layer;
• forming a film of a piezoelectric layer including a second crystal axis on a principal surface of the second intermediate layer after the forming the film of the second intermediate layer;
• and
• forming a functional electrode on the piezoelectric layer;
• wherein
• the first crystal axis is inclined at a first inclination angle with respect to a direction normal to the support substrate;
• the second crystal axis is inclined at a second inclination angle with respect to a direction normal to the piezoelectric layer;
• the second inclination angle is equal to the first inclination angle;
• and
• rotational symmetry of the piezoelectric layer with respect to the second crystal axis is equal to rotational symmetry of the support substrate with respect to the first crystal axis.