Abstract: Embodiments described herein may provide a surface acoustic wave (SAW) device, methods of fabricating the SAW device, and a system incorporating the SAW device. The SAW device may include a piezoelectric substrate and individual resonators may be formed by a plurality of electrodes on the surface of the piezoelectric substrate. A dielectric layer having a positive thermal coefficient of frequency (TCF) may be formed on each of the plurality of electrodes. In various embodiments, temperature compensation may be achieved by providing more or less of the dielectric layer on at least one resonator than on the other resonators based on a configuration of the resonators. In various embodiments, temperature compensation may be achieved by providing at least one resonator with a different duty factor than the other resonators based on a configuration of the resonators.

Abstract: Embodiments described herein may provide a surface acoustic wave (SAW) device, methods of fabricating the SAW device, and a system incorporating the SAW device. The SAW device may include a piezoelectric substrate and individual resonators may be formed by a plurality of electrodes on the surface of the piezoelectric substrate. A dielectric layer having a positive thermal coefficient of frequency (TCF) may be formed on each of the plurality of electrodes. In various embodiments, temperature compensation may be achieved by providing more or less of the dielectric layer on at least one resonator than on the other resonators based on a configuration of the resonators. In various embodiments, temperature compensation may be achieved by providing at least one resonator with a different duty factor than the other resonators based on a configuration of the resonators.

Abstract: Lateral field excitation acoustic resonators and methods of manufacture are disclosed. In one aspect, an acoustically resonating material such as a piezoelectric film or membrane is spaced from a substrate by electrodes having an air gap therebetween. When current flows through the electrodes, lateral field acoustic waves are excited in the resonating material with relatively good coupling and adequate heat dissipation.

Abstract: A guided surface acoustic wave (SAW) device includes a substrate, a piezoelectric layer on the substrate, and a transducer on the piezoelectric layer. The substrate is silicon, and has a crystalline orientation defined by a first Euler angle (?), a second Euler angle (?), and a third Euler angle (?). The first Euler angle (?), the second Euler angle (?), and the third Euler angle (?) are chosen such that a velocity of wave propagation within the substrate is less than 6,000 m/s.

Abstract: Guided Surface Acoustic Wave (SAW) devices with improved quartz orientations are disclosed. A guided SAW device includes a quartz carrier substrate, a piezoelectric layer on a surface of the quartz carrier substrate, and at least one interdigitated transducer on a surface of the piezoelectric layer opposite the quartz carrier substrate. The quartz carrier substrate includes an orientation that provides improved performance parameters for the SAW device, including electromechanical coupling factor, resonator quality factor, temperature coefficient of frequency, and delta temperature coefficient of frequency.

Abstract: A device includes a die and an interdigital transducer on the die. The interdigital transducer includes a first bus bar, a second bus bar, and a number of electrode fingers. The first bus bar is parallel to the second bus bar. The electrode fingers are divided into a first set of electrode fingers and a second set of electrode fingers. The first set of electrode fingers extend obliquely from the first bus bar towards the second bus bar. The second set of electrode fingers extend obliquely from the second bus bar towards the first bus bar, and are parallel to and interleaved with the first set of electrode fingers. By providing the electrode fingers oblique to the bus bars, spurious transverse modes may be suppressed while maintaining the quality factor, electromechanical coupling coefficient, and capacitance of the device.

Abstract: A method of fabricating a bonded wafer with low carrier lifetime in silicon comprises providing a silicon substrate having opposing top and bottom surfaces, modifying a top portion of the silicon substrate to reduce carrier lifetime in the top portion relative to the carrier lifetime in portions of the silicon substrate other than the top portion, bonding a piezoelectric layer having opposing top and bottom surfaces separated by a distance T over the top surface of the silicon substrate, and providing a pair of electrodes having fingers that are inter-digitally dispersed on a top surface of the piezoelectric layer, the electrodes comprising a portion of a Surface Acoustic Wave (SAW) device. The modifying and bonding steps may be performed in any order. The modified top portion of the silicon substrate prevents the creation of a parasitic conductance within that portion during operation of the SAW device.

Abstract: A method of fabricating a bonded wafer with low carrier lifetime in silicon comprises providing a silicon substrate having opposing top and bottom surfaces, modifying a top portion of the silicon substrate to reduce carrier lifetime in the top portion relative to the carrier lifetime in portions of the silicon substrate other than the top portion, bonding a piezoelectric layer having opposing top and bottom surfaces separated by a distance T over the top surface of the silicon substrate, and providing a pair of electrodes having fingers that are inter-digitally dispersed on a top surface of the piezoelectric layer, the electrodes comprising a portion of a Surface Acoustic Wave (SAW) device. The modifying and bonding steps may be performed in any order. The modified top portion of the silicon substrate prevents the creation of a parasitic conductance within that portion during operation of the SAW device.

Abstract: The present disclosure relates to acoustic wave devices, and particularly to high quality factor (Q) transducers for surface acoustic wave (SAW) devices. An exemplary SAW device includes an interdigital transducer (IDT) between two reflective gratings to form a resonator. The resonator operates through shear horizontal mode acoustic waves, and therefore suppression of transverse modes (parallel to electrode fingers of the IDT) is desired. A piston mode can be formed in the resonator to suppress transverse modes, which may also increase energy leakage and result in a lower Q. A higher Q is achieved by adding a fast region at an end of one or more of the electrode fingers of the IDT.

Abstract: Embodiments of a Surface Acoustic Wave (SAW) device having a guided SAW structure that provides spurious mode suppression and methods of fabrication thereof are disclosed. In some embodiments, a SAW device includes a non-semiconductor support substrate, a piezoelectric layer on a surface of the non-semiconductor support substrate, and at least one interdigitated transducer on a surface of the piezoelectric layer opposite the non-semiconductor support substrate. A thickness of the piezoelectric layer, a SAW velocity of the piezoelectric layer, and an acoustic velocity of the non-semiconductor support substrate are such that a frequency of spurious modes above a resonance frequency of the SAW device is above a bulk wave cut-off frequency of the SAW device. In this manner, the spurious modes above the resonance frequency of the SAW device are suppressed.

Abstract: Guided Surface Acoustic Wave (SAW) devices with improved quartz orientations are disclosed. A guided SAW device includes a quartz carrier substrate, a piezoelectric layer on a surface of the quartz carrier substrate, and at least one interdigitated transducer on a surface of the piezoelectric layer opposite the quartz carrier substrate. The quartz carrier substrate includes an orientation that provides improved performance parameters for the SAW device, including electromechanical coupling factor, resonator quality factor, temperature coefficient of frequency, and delta temperature coefficient of frequency.

Abstract: Guided Surface Acoustic Wave (SAW) devices with improved quartz orientations are disclosed. A guided SAW device includes a quartz carrier substrate, a piezoelectric layer on a surface of the quartz carrier substrate, and at least one interdigitated transducer on a surface of the piezoelectric layer opposite the quartz carrier substrate. The quartz carrier substrate includes an orientation that provides improved performance parameters for the SAW device, including electromechanical coupling factor, resonator quality factor, temperature coefficient of frequency, and delta temperature coefficient of frequency.

Abstract: A device includes a die and an interdigital transducer on the die. The interdigital transducer includes a first bus bar, a second bus bar, and a number of electrode fingers. The first bus bar is parallel to the second bus bar. The electrode fingers are divided into a first set of electrode fingers and a second set of electrode fingers. The first set of electrode fingers extend obliquely from the first bus bar towards the second bus bar. The second set of electrode fingers extend obliquely from the second bus bar towards the first bus bar, and are parallel to and interleaved with the first set of electrode fingers. By providing the electrode fingers oblique to the bus bars, spurious transverse modes may be suppressed while maintaining the quality factor, electromechanical coupling coefficient, and capacitance of the device.

Abstract: The present disclosure relates to acoustic wave devices, and particularly to high quality factor (Q) transducers for surface acoustic wave (SAW) devices. An exemplary SAW device includes an interdigital transducer (IDT) between two reflective gratings to form a resonator. The resonator operates through shear horizontal mode acoustic waves, and therefore suppression of transverse modes (parallel to electrode fingers of the IDT) is desired. A piston mode can be formed in the resonator to suppress transverse modes, which may also increase energy leakage and result in a lower Q. A higher Q is achieved by adding a fast region at an end of one or more of the electrode fingers of the IDT.

Abstract: A device includes a die and an interdigital transducer on the die. The interdigital transducer includes a first bus bar, a second bus bar, and a number of electrode fingers. The first bus bar is parallel to the second bus bar. The electrode fingers are divided into a first set of electrode fingers and a second set of electrode fingers. The first set of electrode fingers extend obliquely from the first bus bar towards the second bus bar. The second set of electrode fingers extend obliquely from the second bus bar towards the first bus bar, and are parallel to and interleaved with the first set of electrode fingers. By providing the electrode fingers oblique to the bus bars, spurious transverse modes may be suppressed while maintaining the quality factor, electromechanical coupling coefficient, and capacitance of the device.

Abstract: A guided acoustic wave device includes a substrate, a lithium tantalate layer on the substrate, and a transducer on the lithium tantalate film. The lithium tantalate has a crystalline orientation defined by (YXl)?°, where ? is between 10° and 37°. The inventors discovered that limiting the crystalline orientation of the lithium tantalate in this manner provides significant increases in the electromechanical coupling coefficient of the acoustic wave device, thereby increasing bandwidth and improving performance.

Abstract: A guided surface acoustic wave (SAW) device includes a substrate, a piezoelectric layer on the substrate, and a transducer on the piezoelectric layer. The substrate is silicon, and has a crystalline orientation defined by a first Euler angle (?), a second Euler angle (?), and a third Euler angle (?). The first Euler angle (?), the second Euler angle (?), and the third Euler angle (?) are chosen such that a velocity of wave propagation within the substrate is less than 6,000 m/s.

Abstract: A guided acoustic wave device includes a substrate, a lithium tantalate layer on the substrate, and a transducer on the lithium tantalate film. The lithium tantalate has a crystalline orientation defined by (YXl)?°, where ? is between 10° and 37°. The inventors discovered that limiting the crystalline orientation of the lithium tantalate in this manner provides significant increases in the electromechanical coupling coefficient of the acoustic wave device, thereby increasing bandwidth and improving performance.

Abstract: A device including a piezoelectric substrate, an interdigital transducer (IDT), and an antireflective structure is disclosed herein. The piezoelectric substrate has a front-side surface and a smoothed back-side surface. The IDT is on the front-side surface of the piezoelectric substrate. The antireflective structure is over at least a portion of the smoothed back-side surface of the piezoelectric substrate. By having the antireflective structure on at least a portion of the smoothed back-side surface of the piezoelectric substrate, reflection of spurious bulk acoustic waves toward the front-side surface of the piezoelectric substrate can be reduced and/or eliminated to lessen interference with surface acoustic waves.

Abstract: Embodiments of a Surface Acoustic Wave (SAW) device having a guided SAW structure that provides spurious mode suppression and methods of fabrication thereof are disclosed. In some embodiments, a SAW device includes a non-semiconductor support substrate, a piezoelectric layer on a surface of the non-semiconductor support substrate, and at least one interdigitated transducer on a surface of the piezoelectric layer opposite the non-semiconductor support substrate. A thickness of the piezoelectric layer, a SAW velocity of the piezoelectric layer, and an acoustic velocity of the non-semiconductor support substrate are such that a frequency of spurious modes above a resonance frequency of the SAW device is above a bulk wave cut-off frequency of the SAW device. In this manner, the spurious modes above the resonance frequency of the SAW device are suppressed.