The present disclosure provides a resonator which resonates in a bulk acoustic wave mode. The resonator includes a resonator body, at least one transducer arm and a substrate. The resonator body is deformed at least along a first direction. The transducer arm is connected to the resonator body along the first direction and includes a base, a piezoelectric layer and an electrode layer. The base includes a first end connected to the resonator body. The piezoelectric layer is disposed above the base but not extended to the resonator body, and the electrode layer is disposed above the piezoelectric layer but not extended to the resonator body. The substrate is for securing the transducer arm such that the resonator body is suspended.

Embodiments of the present disclosure relate generally to MEMS resonators. An exemplary MEMS resonator comprises a resonator beam having a length and a width. The length can be an integer multiple of the width. The integer multiple can be at least two. The resonator is configured to resonate at a frequency upon application of an input signal. The TCF of this resonator can be made close to zero, thus providing a temperature stable resonator. The exemplary MEMS resonator thereby has the advantages of high Q, low polarization voltage, low motional impedance and temperature stability of low frequency resonators while being able resonate at high frequencies of 30 MHz to 30 GHz.

MEMS based sensors, particularly capacitive sensors, potentially can address critical considerations for users including accuracy, repeatability, long-term stability, ease of calibration, resistance to chemical and physical contaminants, size, packaging, and cost effectiveness. Accordingly, it would be beneficial to exploit MEMS processes that allow for manufacturability and integration of resonator elements into cavities within the MEMS sensor that are at low pressure allowing high quality factor resonators and absolute pressure sensors to be implemented. Embodiments of the invention provide capacitive sensors and MEMS elements that can be implemented directly above silicon CMOS electronics.

A bulk acoustic wave resonator apparatus includes a resonator member having an annulus shape, and at least one anchor structure coupling the resonator member to a substrate. A perimeter of the resonator member is at least partially defined by respective sidewalls that are slanted at an angle relative to a plane defined by a surface of the resonator member. The surface of the resonator member may be defined by a (100) crystal plane, and the angle of the respective sidewalls may be defined by a (111) crystal plane. Related fabrication methods are also discussed.

A micro-electromechanical system (MEMS) frequency divider apparatus having one or more MEMS resonators on a substrate is presented. A first oscillator frequency, as an approximate multiple of the parametric oscillation frequency, is capacitively coupled from a very closely-spaced electrode (e.g., 40 nm) to a resonant structure of the first oscillator, thus inducing mechanical oscillation. This mechanical oscillation can be coupled through additional MEMS resonators on the substrate. The mechanical resonance is then converted, in at least one of the MEMS resonators, by capacitive coupling back to an electrical signal which is a division of the first oscillation frequency. Output may be generated as a single ended output, or in response to a differential signal between two output electrodes.

A resonator includes an anchor, an outer stiffener ring on an outer perimeter of the resonator, and a plurality of curved springs between the anchor and the outer stiffener ring.

MEMS based sensors, particularly capacitive sensors, potentially can address critical considerations for users including accuracy, repeatability, long-term stability, ease of calibration, resistance to chemical and physical contaminants, size, packaging, and cost effectiveness. Accordingly, it would be beneficial to exploit MEMS processes that allow for manufacturability and integration of resonator elements into cavities within the MEMS sensor that are at low pressure allowing high quality factor resonators and absolute pressure sensors to be implemented. Embodiments of the invention provide capacitive sensors and MEMS elements that can be implemented directly above silicon CMOS electronics.

A MEMS resonator is equipped with a substrate, a moving structure suspended above the substrate in a horizontal plane formed by first and second axes, having first and second arms, parallel to one another and extending along the second axis, coupled at their respective ends by first and second transverse joining elements, forming an internal window. A first electrode structure is positioned outside the window and capacitively coupled to the moving structure. A second electrode structure is positioned inside the window. One of the first and second electrode structures causes an oscillatory movement of the flexing arms in opposite directions along the first horizontal axis at a resonance frequency, and the other electrode structure has a function of detecting the oscillation. A suspension structure has a suspension arm in the window. An attachment arrangement is coupled to the suspension element centrally in the window, near the second electrode structure.

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.

A MEMS device may include: (i) a lower cavity, including a first island, formed within a first layer of the MEMS device; (ii) an upper cavity, including a second island, formed within a second layer of the MEMS device; (iii) a MEMS resonating element arranged in a device layer of the MEMS device and anchored via the first and second islands; (iv) a first set of electrodes for electrostatic actuation and sensing of the MEMS resonating element in an in-plane mode that is arranged in the device layer of the MEMS device; and (v) a second set of electrodes for electrostatic actuation and sensing of the MEMS resonating element in an out-of-plane mode that is electrically isolated from the first set of electrodes and located in the first or second layer of the MEMS device, and wherein the out-of-plane mode is a torsional mode or a saddle mode.