A monolithic integration of phase change material (PCM) switches with a MEMS resonator is provided to implement switching and reconfiguration functionalities. MEMS resonator includes a piezoelectric material to control terminal connections to the electrodes. The PCM is operable between an ON state and an OFF state by application of heat, which causes the phase change material to change from an amorphous state to a crystalline state or from a crystalline state to an amorphous state, the amorphous state and the crystalline state each associated with one of the ON state and the OFF state. A method of fabricating the MEMS resonator with phase change material is provided. A reconfigurable filter system using the MEMS resonators is also provided.

A method of making a SiC resonator includes forming a layer of an oxide material on a relatively thick wafer of SiC; bonding the layer of oxide material on the relatively thick wafer of SiC to a handle wafer having at least an oxide exterior surface, the resulting bond being substantially free of voids; planarizing the relatively thick wafer of SiC to a desired thickness; forming top and bottom electrodes on the wafer of SiC wafer to define a SiC wafer resonator portion; and forming a trench around the top and bottom electrodes, the tench completely penetrating the planarized wafer of SiC around a majority of a distance surrounding said top and bottom electrodes, except for one or more tether regions of the planarized wafer of SiC which remain physically coupled a remaining portion the SiC wafer resonator portion which defines a frame formed of the planarized wafer of SiC surrounding the SiC wafer resonator portion.

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.

A micro-electrical-mechanical system (MEMS) guided wave device includes a plurality of electrodes arranged below a piezoelectric layer (e.g., either embedded in a slow wave propagation layer or supported by a suspended portion of the piezoelectric layer) and configured for transduction of a lateral acoustic wave in the piezoelectric layer. The piezoelectric layer permits one or more additions or modifications to be made thereto, such as trimming (thinning) of selective areas, addition of loading materials, sandwiching of piezoelectric layer regions between electrodes to yield capacitive elements or non-linear elastic convolvers, addition of sensing materials, and addition of functional layers providing mixed domain signal processing utility.

A method of forming an integrated resonator apparatus includes depositing alternating dielectric layers of lower and higher acoustic impedance materials over a substrate. First and second resonator electrodes are formed over the alternating dielectric layers, with a piezoelectric layer located between the first and second resonator electrodes. A mass bias is formed over the first and second resonator electrodes. The mass bias, first and second electrodes, piezoelectric layer, and alternating dielectric layers may be encapsulated with a plastic mold fill.

Embodiments of the invention include microelectronic devices, resonators, and methods of fabricating the microelectronic devices. In one embodiment, a microelectronic device includes a substrate and a plurality of cavities integrated with the substrate. A plurality of vertically oriented resonators are formed with each resonator being positioned in a cavity. Each resonator includes a crystalline or single crystal piezoelectric film.

A micro-electrical-mechanical system (MEMS) guided wave device includes a single crystal piezoelectric layer and at least one guided wave confinement structure configured to confine a laterally excited wave in the single crystal piezoelectric layer. A bonded interface is provided between the single crystal piezoelectric layer and at least one underlying layer. A multi-frequency device includes first and second groups of electrodes arranged on or in different thickness regions of a single crystal piezoelectric layer, with at least one guided wave confinement structure. Segments of a segmented piezoelectric layer and a segmented layer of electrodes are substantially registered in a device including at least one guided wave confinement structure.

A multiplexer includes a first filter on a first path, a second filter on a second path, and a third filter on a third path. A frequency of intermodulation distortion generated by a transmission signal within a pass band of the first filter and a transmission signal within a pass band of the second filter is within a pass band of the third filter. The first filter includes one or more series resonators on the first path and one or more parallel resonators on one or more paths connecting one or more nodes on the first path to a ground. A relative permittivity of a resonator of the one or more series resonators and the one or more parallel resonators that is closest to a common terminal is lowest among relative permittivities of the resonators.

A microelectromechanical resonator device has: a main body, with a first surface and a second surface, opposite to one another along a vertical axis, and made of a first layer and a second layer, arranged on the first layer; a cap, having a respective first surface and a respective second surface, opposite to one another along the vertical axis, and coupled to the main body by bonding elements; and a piezoelectric resonator structure formed by: a mobile element, constituted by a resonator portion of the first layer, suspended in cantilever fashion with respect to an internal cavity provided in the second layer and moreover, on the opposite side, with respect to a housing cavity provided in the cap; a region of piezoelectric material, arranged on the mobile element on the first surface of the main body; and a top electrode, arranged on the region of piezoelectric material, the mobile element constituting a bottom electrode of the piezoelectric resonator structure.

A method of fabricating an FBAR filter device including an array of resonators, each resonator comprising a single crystal piezoelectric film sandwiched between a first metal electrode and a second metal electrode, wherein the first electrode is supported by a support membrane over an air cavity, the air cavity embedded in a silicon dioxide layer over a silicon handle, with through-silicon via holes through the silicon handle and into the air cavity, the side walls of said air cavity in the silicon dioxide layer being defined by perimeter trenches that are resistant to a silicon oxide etchant.