Abstract: In accordance with a representative embodiment, a bulk acoustic wave (BAW) resonator comprises: a first electrode having a first electrode thickness; a second electrode having a second electrode thickness; and a piezoelectric layer having a piezoelectric layer thickness and being disposed between the first and second electrodes, the piezoelectric layer comprising a piezoelectric material doped with at least one rare earth element. For a particular acoustic coupling coefficient (kt2) value and a series resonance frequency (Fs) of the BAW resonator, the first electrode thickness and the second electrode thickness are each greater than a thickness of a first electrode and a thickness of a second electrode of a BAW resonator comprising an undoped piezoelectric layer.

Abstract: A bulk acoustic wave (BAW) resonator, comprises: a first electrode; a second electrode comprising a plurality of sides. At least one of the sides comprises a cantilevered portion. The bulk acoustic wave (BAW) resonator also comprises a piezoelectric layer disposed between the first and second electrodes. The piezoelectric layer comprises an undoped piezoelectric material and a doped piezoelectric material, and the cantilevered portion extends above the piezoelectric layer. The bulk acoustic wave (BAW) resonator comprises a gap between the cantilevered portion and the piezoelectric layer.

Abstract: A bulk acoustic wave (BAW) resonator device includes a bottom electrode on a substrate over one of a cavity and an acoustic mirror, a piezoelectric layer on the bottom electrode, a top electrode on the piezoelectric layer, and a temperature compensation feature having positive temperature coefficient for offsetting at least a portion of a negative temperature coefficient of the piezoelectric layer. At least one of the bottom electrode and the top electrode includes an integrated lateral feature configured to create at least one of a cut-off frequency mismatch and an acoustic impedance mismatch.

Abstract: A bulk acoustic wave (BAW) resonator device includes a bottom electrode on a substrate over one of a cavity and an acoustic reflector, a piezoelectric layer on the bottom electrode, and a top electrode on the piezoelectric layer. At one of the bottom electrode and the top electrode is a composite electrode having an integrated lateral feature, arranged between planar top and bottom surfaces of the composite electrode and configured to create a cut-off frequency mismatch.

Abstract: A bulk acoustic wave (BAW) resonator device includes a substrate defining a cavity, a bottom electrode formed over the substrate and at least a portion of the cavity, a piezoelectric layer formed on the bottom electrode, and a top electrode formed on the piezoelectric layer. An air-wing and an air-bridge are formed between the piezoelectric layer and the top electrode, the air-wing having an inner edge that defines an outer boundary of an active region of the BAW resonator device. The BAW resonator device further includes a temperature compensation feature having positive temperature coefficient for offsetting at least a portion of a negative temperature coefficient of the piezoelectric layer. The temperature compensation feature extends outside the active region by a predetermined length.

Abstract: A bulk acoustic wave (BAW) resonator structure comprises a first electrode disposed over a substrate, a first piezoelectric layer disposed over the first electrode, a second electrode disposed over the first piezoelectric layer, and a collar structure disposed around a perimeter of an active region defined by an overlap between the first electrode, the second electrode, and the piezoelectric layer.

Abstract: A bulk acoustic wave (BAW) resonator structure comprises a first electrode disposed over a substrate, a piezoelectric layer disposed over the first electrode, a second electrode disposed over the first piezoelectric layer, and a guard ring structure formed around a perimeter of an active region corresponding to an overlap of the first electrode, the first piezoelectric layer, and the second electrode.

Abstract: A bulk acoustic wave (BAW) resonator device includes a bottom electrode on a substrate over one of a cavity and an acoustic mirror, a piezoelectric layer on the bottom electrode, a top electrode on the piezoelectric layer, and a temperature compensation feature having positive temperature coefficient for offsetting at least a portion of a negative temperature coefficient of the piezoelectric layer. At least one of the bottom electrode and the top electrode includes an integrated lateral feature configured to create at least one of a cut-off frequency mismatch and an acoustic impedance mismatch.

Abstract: An acoustic resonator device includes a bottom electrode disposed on a substrate over an acoustic reflecting feature, a piezoelectric layer disposed on the bottom electrode and a top electrode disposed on the piezoelectric layer, where an overlap between the top electrode, the piezoelectric layer and the bottom electrode over the acoustic reflecting feature define an active region of the acoustic resonator device. The acoustic resonator device further includes at least one of a wing having an outer edge extending beyond at least a portion of an outer edge of the top electrode, and a first frame formed in one of an outer region or a center region of the top electrode. The at least one of the wing and the first frame has an apodized shape, such that no edges are parallel to one another, the apodized shape of the at least one of the wing and the first frame being different from an electrode shape defined by an outer edge of the top electrode.

Abstract: An acoustic resonator includes a bottom electrode disposed over a substrate, a piezoelectric layer disposed over the bottom electrode, a top electrode disposed over the piezoelectric layer, and a cavity disposed beneath the bottom electrode. An overlap of the bottom electrode, the piezoelectric layer and the top electrode defines a main membrane region of the acoustic resonator structure. The acoustic resonator further includes an acoustic reflector disposed over the substrate adjacent to the cavity, the acoustic reflector including a layer of low acoustic impedance material stacked on a layer of high acoustic impedance material.

Abstract: A bulk acoustic wave (BAW) resonator structure includes a first electrode disposed over a substrate, a piezoelectric layer disposed over the first electrode and a second electrode disposed over the first piezoelectric layer. The piezoelectric layer is formed of a piezoelectric material doped with one of erbium or yttrium at an atomic percentage of greater than three for improving piezoelectric properties of the piezoelectric layer.

Abstract: A bulk acoustic wave (BAW) resonator, comprises: a first electrode; a second electrode comprising a plurality of sides. At least one of the sides comprises a cantilevered portion. The bulk acoustic wave (BAW) resonator also comprises a piezoelectric layer disposed between the first and second electrodes. The piezoelectric layer comprises a piezoelectric material doped with a plurality of rare earth elements, and the cantilevered portion extends above the piezoelectric layer. The bulk acoustic wave (BAW) resonator comprises a gap between the cantilevered portion and the piezoelectric layer.

Abstract: An electrical resonator comprises a substrate comprising a cavity. The electrical resonator comprises a resonator stack suspended over the cavity. The resonator stack comprises a first electrode; a second electrode; a piezoelectric layer; and a temperature compensating layer comprising borosilicate glass (BSG).

Abstract: A film bulk acoustic resonator (FBAR) structure includes a first electrode disposed over a substrate, a piezoelectric layer disposed over the first electrode, and a second electrode disposed over the first piezoelectric layer. A bridge is disposed between the first electrode and the piezoelectric layer.

Abstract: An acoustic resonator comprises a substrate comprising a cavity. The electrical resonator comprises a resonator stack suspended over the cavity. The resonator stack comprises a first electrode; a second electrode; a piezoelectric layer; and a temperature compensating layer comprising borosilicate glass (BSG).

Abstract: A bulk acoustic wave (BAW) resonator having a first electrode, a second electrode, and a piezoelectric layer between the first electrode and the second electrode. The first electrode is of a first electrode material. The second electrode is of a second electrode material. The piezoelectric layer is of a piezoelectric material doped with at least one rare earth element. The BAW resonator has a resonant frequency dependent at least in part on respective thicknesses and materials of the first electrode, the second electrode and the piezoelectric layer. The resonant frequency has a temperature coefficient. At least one of the first electrode and the second electrode includes a niobium alloy electrode material that, relative to molybdenum as the electrode material, reduces the temperature coefficient of the resonant frequency of the BAW resonator.

Abstract: A bulk acoustic wave (BAW) resonator device includes a substrate defining a cavity, a bottom electrode formed over the substrate and at least a portion of the cavity, a piezoelectric layer formed on the bottom electrode, and a top electrode formed on the piezoelectric layer. An air-wing and an air-bridge are formed between the piezoelectric layer and the top electrode, the air-wing having an inner edge that defines an outer boundary of an active region of the BAW resonator device. The BAW resonator device further includes a temperature compensation feature having positive temperature coefficient for offsetting at least a portion of a negative temperature coefficient of the piezoelectric layer. The temperature compensation feature extends outside the active region by a predetermined length.

Abstract: A plasma vapor deposition (PVD) system and method for depositing a piezoelectric layer over a substrate are disclosed. A plasma is created in a reaction chamber creates from the sputtering gas supplied to the reaction chamber. The plasma sputters atoms from the sputtering target, which are deposited on the substrate for forming the thin film of the material.

Abstract: An acoustic resonator device including a piezoelectric layer, a first electrode disposed adjacent to a first surface of the piezoelectric layer, and a second electrode disposed adjacent to a second surface of the piezoelectric layer. At least one of the first electrode and the second electrode includes a first conductive layer disposed adjacent to the piezoelectric layer and having a first acoustic impedance, and a second conductive layer disposed on a side of the first conductive layer opposite the piezoelectric layer and having a second acoustic impedance greater than the first acoustic impedance. The acoustic resonator device further includes at least one lateral feature for increasing quality factor Q of the acoustic resonator structure. The at least one lateral feature includes at least one of an air-ring between the piezoelectric layer and the second electrode, and a frame on at least one of the first electrode and the piezoelectric layer.

Abstract: A bulk acoustic wave (BAW) resonator structure includes a first electrode disposed over a substrate, a piezoelectric layer disposed over the first electrode and a second electrode disposed over the first piezoelectric layer. The piezoelectric layer is formed of a piezoelectric material doped with multiple rare earth elements for improving piezoelectric properties of the piezoelectric layer.