Rotation in xy plane to suppress spurious modes in xbar devices

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, each suspended over a respective cavity of the one or more cavities;
• forming a conductor pattern on the front surface, the conductor pattern including one or more interdigital transducers (IDTs) of a respective one or more resonators, wherein interleaved fingers of the one or more IDTs are disposed on a respective diaphragm of the one or more diaphragms,
• wherein the piezoelectric plate and the one or more IDTs are configured such that radio frequency signals applied to the one or more IDTs excite respective primary shear acoustic modes in the respective one or more diaphragms,
• wherein the interleaved fingers of at least one of the one or more IDTs extend at an oblique angle to an Y crystalline axis of the piezoelectric plate,
• wherein forming one or more cavities comprises forming a plurality of cavities to form a plurality of respective diaphragms, and
• wherein the interleaved fingers of at least one of the IDTs disposed on a respective one of the plurality of diaphragms extend at an angle different from the interleaved fingers of at least one other of the IDTs disposed on a respective diaphragm of the plurality of diaphragms.