A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.

A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.

A resonator comprising a piezoelectric film which creates an acoustic path that is slightly longer in a central region of the resonator than at an edge of the resonator.

A resonator comprising a piezoelectric film which creates an acoustic path that is slightly longer in a central region of the resonator than at an edge of the resonator.

Filter devices and methods of fabrication are disclosed. A filter device includes a piezoelectric plate attached to a substrate, portions of the piezoelectric plate forming diaphragms spanning respective cavities in the substrate. A conductor pattern formed on a surface of the piezoelectric plate includes a plurality of interdigital transducers (IDTs) of a respective plurality of acoustic resonators including a shunt resonator and a series resonator, interleaved fingers of each of the plurality of IDTs disposed on one of the diaphragms. Radio frequency signals applied to the IDTs excite respective primary shear acoustic modes in the respective diaphragms. A thickness of a first dielectric layer disposed on the front surface between the fingers of the IDT of the shunt resonator is greater than a thickness of a second dielectric layer disposed on the front surface between the fingers of the IDT of the series resonator.

Methods of fabricating acoustic filters. A back-side frequency setting layer is formed on a surface of a substrate and/or a back surface of a piezoelectric plate. The piezoelectric plate is attached to the substrate with the back-side frequency setting layer sandwiched between the substrate and the piezoelectric plate. Portions of the piezoelectric plate and backside frequency setting layer form diaphragms spanning respective cavities in the substrate. A conductor pattern defining a plurality of acoustic resonators is formed on a front surface of the piezoelectric plate. Each of the acoustic resonators includes an interdigital transducer (IDT) with interleaved fingers disposed on a respective diaphragm. A front-side frequency setting layer is formed over the interleaved fingers and the front surface of the diaphragms of one or more shunt resonators. The back-side frequency setting layer is removed from the back surfaces of the diaphragms of one or more series resonators.

Methods of fabricating acoustic filters. A back-side frequency setting layer is formed on a surface of a substrate and/or a back surface of a piezoelectric plate. The piezoelectric plate is attached to the substrate with the back-side frequency setting layer sandwiched between the substrate and the piezoelectric plate. Portions of the piezoelectric plate and backside frequency setting layer form diaphragms spanning respective cavities in the substrate. A conductor pattern defining a plurality of acoustic resonators is formed on a front surface of the piezoelectric plate. Each of the acoustic resonators includes an interdigital transducer (IDT) with interleaved fingers disposed on a respective diaphragm. A front-side frequency setting layer is formed over the interleaved fingers and the front surface of the diaphragms of one or more shunt resonators. The back-side frequency setting layer is removed from the back surfaces of the diaphragms of one or more series resonators.

Acoustic resonator devices and filters are disclosed. A piezoelectric plate is attached to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer disposed on the diaphragm, and a first plurality of contact pads. A second conductor pattern is formed on a surface of a base, the second conductor pattern including a second plurality of contact pads. Each pad of the first plurality of contact pads is connected to a respective pad of the second plurality of contact pads. A seal is formed between a perimeter of the piezoelectric plate and a perimeter of the base.

Acoustic filters are disclosed. An acoustic filter device includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces and a thickness ts, the back surface attached to the surface of the substrate except for portions of the piezoelectric plate forming a plurality of diaphragms that span respective cavities in the substrate. A conductor pattern is formed on the front surface of the piezoelectric plate, the conductor pattern comprising a plurality of interdigital transducers (IDTs) of a plurality of acoustic resonators, interleaved fingers of each IDT of the plurality of IDTs disposed on a respective diaphragm of the plurality of diaphragms. The interleaved fingers of all of the plurality of IDTs are substantially aluminum with a common thickness tm, where 0.12 tstm0.32 ts.

Acoustic filters are disclosed. An acoustic filter device includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces and a thickness ts, the back surface attached to the surface of the substrate except for portions of the piezoelectric plate forming a plurality of diaphragms that span respective cavities in the substrate. A conductor pattern is formed on the front surface of the piezoelectric plate, the conductor pattern comprising a plurality of interdigital transducers (IDTs) of a plurality of acoustic resonators, interleaved fingers of each IDT of the plurality of IDTs disposed on a respective diaphragm of the plurality of diaphragms. The interleaved fingers of all of the plurality of IDTs are substantially aluminum with a common thickness tm, where 0.12 tstm0.32 ts.