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 piezoelectric MEMS resonator is provided. The resonator comprises a single crystal silicon microstructure suspended over a buried cavity created in a silicon substrate and a piezoelectric resonance structure located on the microstructure. The resonator is designed and fabricated based on porous silicon related technologies including selective formation and etching of porous silicon in silicon substrate, porous silicon as scarified material for surface micromachining and porous silicon as substrate for single crystal silicon epitaxial growth. All these porous silicon related technologies are compatible with CMOS technologies and can be conducted in a standard CMOS technologies platform.

A piezoelectric MEMS resonator is provided. The resonator comprises a single crystal silicon microstructure suspended over a buried cavity created in a silicon substrate and a piezoelectric resonance structure located on the microstructure. The resonator is designed and fabricated based on porous silicon related technologies including selective formation and etching of porous silicon in silicon substrate, porous silicon as scarified material for surface micromachining and porous silicon as substrate for single crystal silicon epitaxial growth. All these porous silicon related technologies are compatible with CMOS technologies and can be conducted in a standard CMOS technologies platform.

Acoustic resonator devices are disclosed. An acoustic resonator device includes a plurality of cells electrically connected in parallel. Each cell includes an interdigital transducer (IDT) on a piezoelectric plate, the IDT having at least 15 and not more than 35 interleaved fingers.

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 resonant member of a MEMS resonator oscillates in a mechanical resonance mode that produces non-uniform regional stresses such that a first level of mechanical stress in a first region of the resonant member is higher than a second level of mechanical stress in a second region of the resonant member. A plurality of openings within a surface of the resonant member are disposed more densely within the first region than the second region and at least partly filled with a compensating material that reduces temperature dependence of the resonant frequency corresponding to the mechanical resonance mode.

An electronic device package comprises an electrical device disposed on a base substrate, a conductive column in electrical communication with the electrical device and having a first end bonded to the base substrate, a cap substrate disposed over the electrical device and bonded to a second end of the conductive column, a layer of dielectric material disposed on the lower surface of the base substrate, a through substrate via in electrical communication with the conductive column and passing through the base substrate and the layer of dielectric material, a redistribution layer disposed on the layer of dielectric material, and a contact pad formed on the redistribution layer and in electrical communication with the through substrate via through the redistribution layer, the contact pad being horizontally displaced from a position directly below the through substrate via.

A microelectromechanical resonator includes a support structure, a resonator element suspended to the support structure, and an actuator for exciting the resonator element to a resonance mode. The resonator element includes a plurality of adjacent sub-elements each having a length and a width and a length-to-width aspect ratio of higher than 1 and being adapted to a resonate in a length-extensional, torsional or flexural resonance mode. Further, each of the sub-elements is coupled to at least one other sub-element by one or more connection elements coupled to non-nodal points of the of said resonance modes of the sub-elements for exciting the resonator element into a collective resonance mode.

A bulk-acoustic-mode MEMS resonator has a first portion with a first physical layout, and a layout modification feature. The resonant frequency is a function of the physical layout, which is designed such that the frequency variation is less than 150 ppm for a variation in edge position of the resonator shape edges of 50 nm. This design combines at least two different layout features in such a way that small edge position variations (resulting from uncontrollable process variation) have negligible effect on the resonant frequency.

An electronic package includes a die mounted on a first substrate; a second substrate disposed over the first substrate; a pillar wall extending between a surface of the die and an opposing surface of the second substrate to provide separation between the die and the second substrate, the pillar wall extending about a perimeter bounding the die and enclosing a cavity between the first and second substrates; and an encapsulating layer disposed over the first and second substrates and around the pillar wall. Substantially none of the encapsulating layer ingresses into the cavity.