Abstract: A device includes a piezoelectric layer on a substrate and including a portion included in an acoustic resonator, a first conductive layer on the piezoelectric layer and including a first electrode of the acoustic resonator on a first side of resonator portion of the piezoelectric layer, and a second conductive layer on the piezoelectric layer and including a second electrode of the acoustic resonator on a second side of the resonator portion of the piezoelectric layer. An insulating layer is disposed on the second conductive layer and an interconnection metal layer is electrically connected to the second conductive layer or the first conductive layer and has a portion extending onto the insulating layer and overlapping a portion of the second conductive layer to provide a capacitor electrode of a capacitor coupled to the first electrode and/or the second electrode.

Abstract: A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. Patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the electrodes and a planarized support layer is deposited over the sacrificial layer. The device can include a dielectric protection layer (DPL) that protects the piezoelectric layer from etching processes that can produce rough surfaces and reduces parasitic capacitance around the perimeter of the resonator when the DPL’s dielectric constant is lower than that of the piezoelectric layer. The DPL can be configured between the top electrode and the piezoelectric layer, between the bottom electrode and the piezoelectric layer, or both.

Abstract: A piezoelectric resonator device can be formed to include a piezoelectric film including an active area configured to provide a thickness excited mode of vibration, a first electrode on a first surface of the piezoelectric film positioned to electromechanically couple to the active area, a second electrode on a second surface of the piezoelectric film, opposite the first surface, the second electrode positioned to electromechanically couple to the active area, an energy confinement frame extending on the piezoelectric film embedded in the first or second electrode, an inner side wall of the energy confinement frame facing toward the active area and extending around the active area to define a perimeter that separates the active area located inside the perimeter from an outer area located outside the perimeter adjacent to the active area, an outer side wall of the energy confinement frame facing toward the outer area and aligned to an outer side wall of the first or second electrode and a conformal low-impedan

Abstract: A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. Patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the electrodes and a planarized support layer is deposited over the sacrificial layer. The device can include a dielectric protection layer (DPL) that protects the piezoelectric layer from etching processes that can produce rough surfaces and reduces parasitic capacitance around the perimeter of the resonator when the DPL's dielectric constant is lower than that of the piezoelectric layer. The DPL can be configured between the top electrode and the piezoelectric layer, between the bottom electrode and the piezoelectric layer, or both.

Abstract: Methods and systems for reducing stiction through roughening the surface and reducing the contact area in MEMS devices are disclosed. A method includes fabricating bumpstops on a surface of a MEMS device substrate to reduce stiction. Another method is directed to applying roughening etchant to a surface of a silicon substrate to enhance roughness after cavity etch and before removal of hardmask. Another embodiment described herein is directed to a method to reduce contact area between proof mass and UCAV (“upper cavity”) substrate surface with minimal impact on the cavity volume by introducing a shallow etch process step and maintaining high pressure in accelerometer cavity. Another method is described as to increasing the surface roughness of a UCAV substrate surface by depositing a rough layer (e.g. polysilicon) on the surface of the substrate and etching back the rough layer to transfer the roughness.

Abstract: A piezoelectric micromachined ultrasound transducer (PMUT) device may include a plurality of layers including a structural layer, a piezoelectric layer, and electrode layers located on opposite sides of the piezoelectric layer. Conductive barrier layers may be located between the piezoelectric layer and the electrodes to the prevent diffusion of the piezoelectric layer into the electrode layers.

Abstract: A device includes a piezoelectric layer on a substrate and including a portion included in an acoustic resonator, a first conductive layer on the piezoelectric layer and including a first electrode of the acoustic resonator on a first side of resonator portion of the piezoelectric layer, and a second conductive layer on the piezoelectric layer and including a second electrode of the acoustic resonator on a second side of the resonator portion of the piezoelectric layer. An insulating layer is disposed on the second conductive layer and an interconnection metal layer is electrically connected to the second conductive layer or the first conductive layer and has a portion extending onto the insulating layer and overlapping a portion of the second conductive layer to provide a capacitor electrode of a capacitor coupled to the first electrode and/or the second electrode.

Abstract: A BAW resonator ladder topology pass-band filter can include a plurality of series branches each including BAW series resonators. A plurality of shunt branches can each include BAW shunt resonators, wherein the plurality of series branches are coupled to the plurality of shunt branches to provide the BAW resonator ladder topology pass-band filter. A high-impedance shunt branch can include a plurality of high-impedance BAW shunt resonators coupled together in-series to provide an impedance for the high-impedance shunt branch that is greater the other shunt branches in the BAW resonator ladder topology pass-band filter.

Abstract: A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. Patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the electrodes and a planarized support layer is deposited over the sacrificial layer. The device can include a dielectric protection layer (DPL) that protects the piezoelectric layer from etching processes that can produce rough surfaces and reduces parasitic capacitance around the perimeter of the resonator when the DPL's dielectric constant is lower than that of the piezoelectric layer. The DPL can be configured between the top electrode and the piezoelectric layer, between the bottom electrode and the piezoelectric layer, or both.

Abstract: Methods and systems for reducing stiction through roughening the surface and reducing the contact area in MEMS devices are disclosed. A method includes fabricating bumpstops on a surface of a MEMS device substrate to reduce stiction. Another method is directed to applying roughening etchant to a surface of a silicon substrate to enhance roughness after cavity etch and before removal of hardmask. Another embodiment described herein is directed to a method to reduce contact area between proof mass and UCAV (“upper cavity”) substrate surface with minimal impact on the cavity volume by introducing a shallow etch process step and maintaining high pressure in accelerometer cavity. Another method is described as to increasing the surface roughness of a UCAV substrate surface by depositing a rough layer (e.g. polysilicon) on the surface of the substrate and etching back the rough layer to transfer the roughness.

Abstract: A piezoelectric micromachined ultrasound transducer (PMUT) device may include a plurality of layers including a structural layer, a piezoelectric layer, and electrode layers located on opposite sides of the piezoelectric layer. Conductive barrier layers may be located between the piezoelectric layer and the electrodes to the prevent diffusion of the piezoelectric layer into the electrode layers.