A moveable micromachined member of a microelectromechanical system (MEMS) device includes an insulating layer disposed between first and second electrically conductive layers. First and second mechanical structures secure the moveable micromachined member to a substrate of the MEMS device and include respective first and second electrical interconnect layers coupled in series, with the first electrically conductive layer of the moveable micromachined member and each other, between first and second electrical terminals to enable conduction of a first joule-heating current from the first electrical terminal to the second electrical terminal through the first electrically conductive layer of the moveable micromachined member.

A resonator has a resonator body and a frame at least partially surrounding the resonator body, the resonator body being coupled to the frame by at least one tether. The resonator body, frame and at least one tether comprise silicon carbide. A plurality of interdigitated electrodes are disposed on the silicon carbide resonator body. The resonator body preferably comprises 6H silicon carbide and preferably has a crystalline c-axis oriented generally parallel to a thickness direction of the resonator body.

Techniques are disclosed for forming high frequency film bulk acoustic resonator (FBAR) devices having multiple resonator thicknesses on a common substrate. A piezoelectric stack is formed in an STI trench and overgrown onto the STI material. In some cases, the piezoelectric stack can include epitaxially grown AlN. In some cases, the piezoelectric stack can include single crystal (epitaxial) AlN in combination with polycrystalline (e.g., sputtered) AlN. The piezoelectric stack thus forms a central portion having a first resonator thickness and end wings extending from the central portion having a different resonator thickness. Each wing may also have different thicknesses. Thus, multiple resonator thicknesses can be achieved on a common substrate, and hence, multiple resonant frequencies on that same substrate. The end wings can have metal electrodes formed thereon, and the central portion can have a plurality of IDT electrodes patterned thereon.

Techniques are disclosed for forming high frequency film bulk acoustic resonator (FBAR) devices having multiple resonator thicknesses on a common substrate. A piezoelectric stack is formed in an STI trench and overgrown onto the STI material. In some cases, the piezoelectric stack can include epitaxially grown AlN. In some cases, the piezoelectric stack can include single crystal (epitaxial) AlN in combination with polycrystalline (e.g., sputtered) AlN. The piezoelectric stack thus forms a central portion having a first resonator thickness and end wings extending from the central portion having a different resonator thickness. Each wing may also have different thicknesses. Thus, multiple resonator thicknesses can be achieved on a common substrate, and hence, multiple resonant frequencies on that same substrate. The end wings can have metal electrodes formed thereon, and the central portion can have a plurality of IDT electrodes patterned thereon.

A MEMS resonator is operated at its parallel resonance frequency. An acoustic wave is propagated laterally away from a central region of the MEMS resonator through a piezoelectric layer of the MEMS resonator. The propagating acoustic wave is attenuated with concentric confiners that surround and are spaced apart from a perimeter of an electrode that forms the MEMS resonator.

A MEMS resonator is operated at its parallel resonance frequency. An acoustic wave is propagated laterally away from a central region of the MEMS resonator through a piezoelectric layer of the MEMS resonator. The propagating acoustic wave is attenuated with concentric confiners that surround and are spaced apart from a perimeter of an electrode that forms the MEMS resonator.

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film provided on the substrate; a lower electrode and an upper electrode that sandwich at least a part of the piezoelectric film and face with each other; and an inserted film that is inserted in the piezoelectric film, is provided on an outer circumference region in a resonance region in which the lower electrode and the upper electrode sandwich the piezoelectric film and face with each other, is not provided in a center region of the resonance region, and has a cutout in the resonance region.

An elastic wave apparatus includes a piezoelectric substrate, an IDT electrode on the piezoelectric substrate and includes first electrode fingers, second electrode fingers, a first busbar, and a second busbar, a capacitive electrode including third electrode fingers, fourth electrode fingers, a third busbar, and a fourth busbar, an insulating film laminated on the capacitive electrode, a first wiring line including a first portion facing the capacitive electrode via the insulating film, and a second wiring line that connects the first busbar and the third busbar. The capacitive electrode extends in a lateral direction with respect to the IDT electrode in a surface acoustic wave propagation direction.

An elastic wave apparatus includes a piezoelectric substrate, an IDT electrode on the piezoelectric substrate and includes first electrode fingers, second electrode fingers, a first busbar, and a second busbar, a capacitive electrode including third electrode fingers, fourth electrode fingers, a third busbar, and a fourth busbar, an insulating film laminated on the capacitive electrode, a first wiring line including a first portion facing the capacitive electrode via the insulating film, and a second wiring line that connects the first busbar and the third busbar. The capacitive electrode extends in a lateral direction with respect to the IDT electrode in a surface acoustic wave propagation direction.

An acoustic resonator structure comprises a first electrode disposed on a substrate, a piezoelectric layer disposed on the first electrode, a second electrode disposed on the piezoelectric layer, and an air cavity disposed in the substrate below at least a portion of a main membrane region defined by an overlap between the first electrode. The acoustic resonator structure may further comprise various integrated structures at or around the main membrane region to improve its electrical performance.