A microelectromechanical device having a mobile structure including mobile arms formed from a composite material and having a fixed structure including fixed arms capacitively coupled to the mobile arms. The composite material includes core regions of insulating material and a silicon coating.

An acoustic resonator includes a piezoelectric stack including a piezoelectric layer having a top surface and a bottom surface, a top electrode layer disposed above the top surface, and a bottom electrode layer disposed below the bottom surface. A number of acoustic wave reflectors are disposed on a side of the bottom electrode layer opposite the piezoelectric layer. Each acoustic wave reflector includes a high acoustic impedance layer and may include a low acoustic impedance layer. The acoustic resonator may include a tether that extends laterally to a stacking direction of the layers of the piezoelectric stack. A supporting structure may be coupled to the tether opposite the acoustic resonator for anchoring the acoustic resonator. A mirror, one or more phononic crystals, or both may be positioned on proximate the tether opposite the acoustic resonator to avoid resonant waves from exiting the acoustic resonator in use.

A resonator is provided that includes a vibration portion having a first and second electrodes, a piezoelectric film disposed therebetween and having a first face opposing the first electrode, and at least two temperature characteristic adjustment films formed to oppose the first face of the piezoelectric film with the first electrode interposed therebetween. Moreover, the resonator includes a frame that surrounds at least part of the vibration portion; and a holding arm connecting the vibration portion to the holding portion. The vibration portion includes a surface opposing the first face of the piezoelectric film and having first and second regions in which an average amount of displacement is larger than an average amount of displacement in the first region when the vibration portion vibrates.

There is provided a dual-output microelectromechanical system (MEMS) resonator. The MEMS resonator can be operated selectively and concurrently in an in-plane mode of vibration and an out-of-plane mode of vibration to obtain respectively a first electrical signal having a first frequency, and a second electrical signal having a second frequency being less than the first frequency. The first and second electrical signals are mixed to obtain a third electrical signal having a third frequency, where the third frequency is proportional to a temperature of the MEMS resonator. The temperature is determined based on the third frequency. Values of the first and second frequencies can be adjusted based on the determined temperature to compensate for frequency deviations due to temperature deviations. There is also provided methods and systems for determining the temperature of the dual-output MEMS, for compensating the frequency, and a method of manufacturing the dual-output MEMS.

In examples, a device comprises a semiconductor die, a thin-film layer, and an air cavity positioned between the semiconductor die and the thin-film layer. The air cavity comprises a resonator positioned on the semiconductor die. A rib couples to a surface of the thin-film layer opposite the air cavity.

In examples, a device comprises a semiconductor die, a thin-film layer, and an air cavity positioned between the semiconductor die and the thin-film layer. The air cavity comprises a resonator positioned on the semiconductor die. A rib couples to a surface of the thin-film layer opposite the air cavity.

A MEMS resonator is described.

A vibrator element includes: a base; an arm that is made of silicon and continuous with the base; a silicon dioxide layer arranged on the arm and a continuous portion in which the arm and the base are continuous; a zirconium dioxide layer arranged on the silicon dioxide layer at least in the continuous portion; a first electrode arranged on the zirconium dioxide layer; a piezoelectric layer arranged on the first electrode; and a second electrode arranged on the piezoelectric layer.

A vibrator that includes a silicon substrate, an electrode facing a surface of the silicon substrate, and a piezoelectric body between the silicon substrate and the electrode and that produces contour vibration in a plane along the surface of the silicon substrate in accordance with a voltage applied to the electrode. The vibrator includes one or more substantially rectangular vibration regions each having a long side parallel to a node of the contour vibration of the piezoelectric body and a short side orthogonal to the node of the contour vibration of the piezoelectric body and corresponding to a half-wavelength of the contour vibration. The resonator satisfies W/T≥4 and y=−0.85×(1/T)+0.57±0.05 where T is the thickness of the silicon substrate, W is the width of the short side of the vibration region, and y is the resistivity of the silicon substrate.

There is provided a dual-output microelectromechanical system (MEMS) resonator. The MEMS resonator can be operated selectively and concurrently in an in-plane mode of vibration and an out-of-plane mode of vibration to obtain respectively a first electrical signal having a first frequency, and a second electrical signal having a second frequency being less than the first frequency. The first and second electrical signals are mixed to obtain a third electrical signal having a third frequency, where the third frequency is proportional to a temperature of the MEMS resonator. The temperature is determined based on the third frequency. Values of the first and second frequencies can be adjusted based on the determined temperature to compensate for frequency deviations due to temperature deviations. There is also provided methods and systems for determining the temperature of the dual-output MEMS, for compensating the frequency, and a method of manufacturing the dual-output MEMS.