The disclosure relates to the technical field of semiconductors, and discloses a method for manufacturing a resonator. The method includes: a substrate is pretreated to change a preset reaction rate of a preset region part of the substrate, so that the preset reaction rate of the preset region part is higher than that of a region outside the preset region part; a preset reaction is performed to the substrate to form a sacrificial material part including an upper half part above an upper surface of the substrate and a lower half part below a lower surface of the substrate; a multilayer structure is formed on the sacrificial material part, and includes a lower electrode layer, a piezoelectric layer and an upper electrode layer from bottom to top; and the sacrificial material part is removed.

The disclosure relates to the technical field of semiconductors, and discloses a method for manufacturing a resonator. The method includes: a substrate is pretreated to change a preset reaction rate of a preset region part of the substrate, so that the preset reaction rate of the preset region part is higher than that of a region outside the preset region part; a preset reaction is performed to the substrate to form a sacrificial material part including an upper half part above an upper surface of the substrate and a lower half part below a lower surface of the substrate; a multilayer structure is formed on the sacrificial material part, and includes a lower electrode layer, a piezoelectric layer and an upper electrode layer from bottom to top; and the sacrificial material part is removed.

A resonator includes a vibration portion with upper and lower electrodes with a piezoelectric film disposed therebetween. Moreover, a protective film is provided to face the piezoelectric film with the upper electrode interposed therebetween and is exposed in a first region in the vibration portion. A conductive film is provided to face the piezoelectric film with the protective film interposed therebetween and is exposed in a second region that is adjacent to the first region in the vibration portion. A connection electrode is formed in the protective film to electrically connect the conductive film to the lower electrode. The upper electrode is formed such that an area of a region overlapping the conductive film is equal to or smaller than half of a total area of the conductive film and/or avoids the region overlapping the conductive film.

Methods of fabricating acoustic resonators are disclosed. A back surface of a single-crystal piezoelectric plate is bonded to a surface of a substrate. A conductor pattern is formed on the front surface of the piezoelectric plate, the conductor pattern including a plurality of interdigital transducers (IDTs) of a plurality of resonators. A dielectric passivation/tuning layer is formed over the conductor pattern and the front surface of the piezoelectric plate. Electrical measurements are made on at least some of the plurality of resonators. Material is selectively removed from the dielectric passivation/tuning layer in accordance with the electrical measurements. After removing material from the dielectric passivation/tuning layer, cavities are formed in the substrate such that interleaved fingers of each IDT are disposed on a respective diaphragm spanning a respective cavity

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 directly bonded to a respective pad of the second plurality of contact pads. A ring-shaped seal is form between a perimeter of the piezoelectric plate and a perimeter of the base.

Filter devices and methods are disclosed. A filter device includes a substrate having a surface. A back surface of a single-crystal piezoelectric plate is attached to the surface of the substrate, portions of the single-crystal piezoelectric plate forming a plurality of diaphragms spanning respective cavities in the substrate. A conductor pattern is formed on a front surface of the piezoelectric plate, the conductor pattern including a plurality of interdigital transducers (IDTs) of a plurality of resonators. Interleaved fingers of at least a first IDT of the plurality of IDTs are disposed on a diaphragm having a first thickness, and interleaved fingers of at least a second IDT of the plurality of IDTs are disposed on a diaphragm having a second thickness less than the first thickness.

Methods of fabricating acoustic resonators are disclosed. A back surface of a piezoelectric plate is bonded to a surface of a substrate. Thickness measurements are made at a plurality of positions on the piezoelectric plate. Excess material is removed from the front surface of the piezoelectric plate in accordance with the thickness measurements to improve a thickness uniformity of the piezoelectric plate. A conductor pattern is formed on the front surface, the conductor pattern including a plurality of interdigital transducers (IDTs) of a plurality of resonators. Cavities are formed in the substrate such that portions of the single-crystal piezoelectric plate form a plurality of diaphragms spanning respective cavities, wherein interleaved fingers of each IDT of the plurality of IDTs are disposed on a respective one of the plurality of diaphragms.

Surface acoustic wave (SAW) resonator, SAW filters, and methods of fabricating SAW filters. A first plurality of parallel conductors extending from a first bus bar are formed on a surface of a 128-degree Y-cut lithium niobate substrate. A second plurality of parallel conductors extending from a second bus bar are formed on the surface of the substrate, the second plurality of parallel conductors interleaved with the first plurality of parallel conductors. An SiO2 layer overlays the first and second pluralities of parallel conductors. The first and second pluralities of parallel conductors are substantially copper and have a thickness D.sub.CU defined by 0.12PD.sub.CU0.24P, where P is a center-to-center spacing of adjacent parallel conductors. The SiO2 layer has a thickness D.sub.OX defined by 3.1D.sub.CUD.sub.OX4.5D.sub.CU.

There is disclosed acoustic resonators and filter devices. An acoustic resonator includes a single-crystal piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm. An interdigital transducer (IDT) is formed on the front surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm. The interleaved fingers of the IDT are substantially molybdenum. The diaphragm is contiguous with the piezoelectric plate around at least 50% of the IDT.

There is disclosed acoustic resonators and filter devices. An acoustic resonator includes a single-crystal piezoelectric plate having front and back surfaces, a portion of the piezoelectric plate forming a diaphragm. An interdigital transducer (IDT) is formed on the front surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm. The interleaved fingers of the IDT are substantially molybdenum. The diaphragm is contiguous with the piezoelectric plate around at least 50% of the IDT.