Abstract: In a method for manufacturing a piezoelectric oscillating circuit in thin film technology, wherein the oscillating circuit includes a predetermined natural frequency and a plurality of layers, first of all at least a first layer of the piezoelectric oscillating circuit is generated. Subsequently, by processing the first layer a frequency correction is performed. Subsequently, at least a second layer of the piezoelectric oscillating circuit is generated and processed for performing a second frequency correction.

Abstract: In accordance with a representative embodiment, a BAW resonator structure comprises: a first BAW resonator comprising a first lower electrode, a first upper electrode and a first piezoelectric layer disposed between the first lower electrode and the first upper electrode; and a second BAW resonator comprising a second lower electrode, a second upper electrode and a second piezoelectric layer disposed between the second lower electrode and the second upper electrode. The BAW resonator structure also comprises a single-material acoustic coupling layer disposed between the first and second BAW resonators. The single-material acoustic coupling layer comprises an inhomogeneous acoustic property across a thickness of the single-material acoustic coupling layer.

Abstract: In accordance with a representative embodiment, a BAW resonator structure comprises: a first BAW resonator comprising a first lower electrode, a first upper electrode and a first piezoelectric layer disposed between the first lower electrode and the first upper electrode; and a second BAW resonator comprising a second lower electrode, a second upper electrode and a second piezoelectric layer disposed between the second lower electrode and the second upper electrode. The BAW resonator structure also comprises a single-material acoustic coupling layer disposed between the first and second BAW resonators. The single-material acoustic coupling layer comprises an inhomogeneous acoustic property across a thickness of the single-material acoustic coupling layer.

Abstract: An apparatus includes a first bulk acoustic wave (BAW) device including a first impedance and a second BAW device including a second impedance, wherein the first and second impedances are different and the first and second BAW devices are acoustically coupled.

Abstract: In one embodiment, a method of producing a resonator in thin-film technology is described. The resonator comprises a piezoelectric layer arranged at least partially between a lower electrode and an upper electrode, the resonator being formed over a substrate. The method comprises: forming the lower electrode of the resonator over the substrate; depositing and patterning an insulating layer over the substrate, the insulating layer comprising a thickness substantially equal to a thickness of the lower electrode; removing a portion of the insulating layer to partially expose a surface of the lower electrode; removing a portion of the insulating layer over the surface of the lower electrode by chemical mechanical polishing; forming the piezoelectric layer over the lower electrode; and producing the upper electrode on the piezoelectric layer.

Abstract: In a method of producing an electrode for a resonator in thin-film technology, the electrode of the resonator is embedded in an insulating layer such that a surface of the electrode is exposed, and that a surface defined by the electrode and the insulating layer is substantially planar.

Abstract: An apparatus includes a first bulk acoustic wave (BAW) device including a first impedance and a second BAW device including a second impedance, wherein the first and second impedances are different and the first and second BAW devices are acoustically coupled.

Abstract: An acoustic resonator is described, the acoustic resonator comprising a stack of a first and a second piezoelectric body, wherein said first and second piezoelectric bodies have substantially the same spatial piezoelectric orientation, an intermediate intermediate electrode being arranged between said first and said second piezoelectric body forming a first terminal of said acoustic resonator, and first and second electrodes, wherein said first electrode is arranged such that said first piezoelectric body is arranged between said first electrode and said intermediate electrode, wherein said second electrode is arranged such that said second piezoelectric body is arranged between said second electrode and said intermediate electrode, and wherein said first and said second electrode are electrically connected to each other forming a second terminal of said acoustic resonator.

Abstract: In a method for manufacturing a piezoelectric oscillating circuit in thin film technology, wherein the oscillating circuit includes a predetermined natural frequency and a plurality of layers, first of all at least a first layer of the piezoelectric oscillating circuit is generated. Subsequently, by processing the first layer a frequency correction is performed. Subsequently, at least a second layer of the piezoelectric oscillating circuit is generated and processed for performing a second frequency correction.

Abstract: In a method for manufacturing a piezoelectric oscillating circuit in thin film technology, wherein the oscillating circuit includes a predetermined natural frequency and a plurality of layers, first of all at least a first layer of the piezoelectric oscillating circuit is generated. Subsequently, by processing the first layer a frequency correction is performed. Subsequently, at least a second layer of the piezoelectric oscillating circuit is generated and processed for performing a second frequency correction.

Abstract: An acoustic resonator is described, the acoustic resonator comprising a stack of a first and a second piezoelectric body, wherein said first and second piezoelectric bodies have substantially the same spatial piezoelectric orientation, an intermediate intermediate electrode being arranged between said first and said second piezoelectric body forming a first terminal of said acoustic resonator, and first and second electrodes, wherein said first electrode is arranged such that said first piezoelectric body is arranged between said first electrode and said intermediate electrode, wherein said second electrode is arranged such that said second piezoelectric body is arranged between said second electrode and said intermediate electrode, and wherein said first and said second electrode are electrically connected to each other forming a second terminal of said acoustic resonator.

Abstract: A filter device and a method for fabricating filter devices can package filters, especially acoustic wave filters, by bonding a carrier (substrate) wafer carrying manufactured filters to another wafer referred to as a capping wafer. A capping wafer/substrate eliminates the need for a conventional package to protect the sensitive filters, which reduces both product size and product costs significantly. Even though additional packaging is possible (i.e. in plastic molded packages, or in glob-top packages), it is not required for the reliability of the filters.

Abstract: The invention relates to bulk acoustic wave filters including at least two bulk acoustic wave resonators. Each of these resonators includes at least one first electrode, a piezoelectric layer, and a second electrode. At least two of the bulk acoustic wave resonators have effective resonator surfaces which differ in their surface form and/or surface content. The inventive design of the bulk acoustic wave resonators enables optimal suppression of interference modes without influencing the impedance level of the filter.

Abstract: A semiconductor component is provided having a layer sequence for conversion of acoustic to thermal signals and electrical voltage changes to one another, as well as a process for its production. The layer sequence has a lower electrode, an upper electrode and a layer which is arranged between them and is piezoelectrical or pyroelectrical. An auxiliary layer is arranged between the lower electrode and the layer and is used for homogeneously oriented growth of the layer during the production process. The auxiliary layer preferably consists essentially of amorphous silicon, amorphous silicon oxide or amorphous silicon nitride.

Abstract: In a method for manufacturing a piezoelectric oscillating circuit in thin film technology, wherein the oscillating circuit includes a predetermined natural frequency and a plurality of layers, first of all at least a first layer of the piezoelectric oscillating circuit is generated. Subsequently, by processing the first layer a frequency correction is performed. Subsequently, at least a second layer of the piezoelectric oscillating circuit is generated and processed for performing a second frequency correction.

Abstract: A resonator apparatus has a piezoelectric resonator as well as an acoustic reflector which has a layer having a high acoustic impedance and a layer having a low acoustic impedance. The thickness of one layer is set different from a quarter of the wavelength in this layer at the operating frequency due to technological limitations in the manufacturing of this layer, and the thickness of the other layer is set dependent from the one layer, such that a predetermined minimum quality of the acoustic reflector is attained.

Abstract: A resonator apparatus has a piezoelectric resonator as well as an acoustic reflector which has a layer having a high acoustic impedance and a layer having a low acoustic impedance. The thickness of one layer is set different from a quarter of the wavelength in this layer at the operating frequency due to technological limitations in the manufacturing of this layer, and the thickness of the other layer is set dependent from the one layer, such that a predetermined minimum quality of the acoustic reflector is attained.

Abstract: The resonator comprises a first electrode (E1), a second electrode (E2) and a piezoelectric layer (P) arranged between the above. A first acoustic compression layer (V1) is arranged between the piezoelectric layer (E1) and the first electrode (E1) with a higher acoustic impedance than the first electrode (E1).

Abstract: The layer sequence has a lower electrode (U), an upper electrode (O) and a layer (S) which is arranged between them and is piezoelectrical or pyroelectrical. An auxiliary layer (H) is arranged between the lower electrode (U) and the layer (S) and is used for homogeneously oriented growth of the layer (S) during the production process. The auxiliary layer (H) is preferably composed essentially of amorphous silicon, amorphous silicon oxide or amorphous silicon nitride.

Abstract: An acoustic mirror is described which is formed of at least one first insulating layer, a first metal layer disposed thereon, a second insulating layer disposed thereon and a second metal layer disposed thereon. An auxiliary layer is produced on the first insulating layer whereby a recess extending as far as the first insulating layer is created therein. The first metal layer is substantially deposited and removed by chemical/mechanical polishing until the parts of the first metal layer disposed outside the recess are no longer present. The second metal layer is also produced in a recess with the aid of chemical/mechanical polishing. More than two insulating layers and two metal layers can be provided. The first metal layer and the second metal layer can be produced in the same recess.