XBAR resonators with non-rectangular diaphragms

A method of fabricating a filter device on a piezoelectric plate having front and back surfaces, the back surface attached to a substrate, the method comprising:

• forming one or more cavities in the substrate such that respective portions of the piezoelectric plate form one or more diaphragms suspended over the one or more cavities, each diaphragm having a respective edge about a perimeter of a respective cavity;
• and
• forming a conductor pattern on the front surface, the conductor pattern including a plurality of interdigital transducers (IDTs) of a respective plurality of resonators including a shunt resonator and a series resonator, wherein interleaved fingers of each of the plurality of IDTs are disposed on a respective diaphragm of the one or more diaphragms, wherein the piezoelectric plate and all of the plurality of IDTs are configured such that radio frequency signals applied to the IDTs excite respective primary shear acoustic modes in the respective diaphragms, wherein at least a portion of the edge of at least one diaphragm is at an oblique angle to the respective fingers, and wherein the at least a portion of the edge of the at least one diaphragm is also at the oblique angle to an X crystalline axis of the piezoelectric plate.