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 vibrator is a piezoelectric vibrator including a vibration portion. The vibration portion has an n-type Si layer which is a degenerated semiconductor and which has a resistivity of not less than 0.5 mΩcm and not greater than 1.2 mΩcm and preferably not greater than 0.9 mΩcm.

An electronic component that includes an electronic element; a base member having an upper surface on which the electronic element is mounted; and a lid member bonded to the base member via a bonding member such that the electronic element is hermetically sealed therebetween. The bonding member is made of an insulating material containing a first metal. The lid member has an outermost layer formed on at least a surface of the lid member facing the base member. The outermost layer of the lid member has a solid solution layer of the first metal and a second metal at at least a portion of the outermost layer.

An electronic device according to an embodiment includes: an antenna, a filter configured to pass a signal of a specific frequency band among signals transmitted and received through the antenna, and a processor configured to control the filter to pass the signal of the specific frequency band. The filter includes: a first substrate, a second substrate facing the first substrate, a first group of electrodes disposed inside the first substrate, a second group of electrodes disposed inside the second substrate, a first transducer electrode including a first group of lines, a second transducer electrode including a second group of lines disposed to alternate with the first group of lines, and a power supply configured to apply voltages to the first group of electrodes and the second group of electrodes. The processor is configured to cause at least one of the second group of lines to be separated from the first substrate, by controlling the power supply based on a frequency of a signal to be passed through the filter.

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 package structure that includes a pair of substrates arranged to oppose each other so as to form an internal space; a bonding portion sealing the pair of substrates; an element is sealed in the internal space and surrounded by the pair of substrates; an adsorption layer within the internal space and opposing at least one substrate of the pair of substrates, the adsorption layer constructed to adsorbs at least hydrogen; and a diffusion-inhibiting layer between the at least one substrate and the adsorption layer, and in which hydrogen is more difficult to diffuse compared with in the at least one substrate.

A resonator that includes a vibrating portion that has a piezoelectric film, and a lower and upper electrodes that face each other with the piezoelectric film interposed therebetween. Moreover, a holding portion is provided at least around a maximum displacement region of the vibrating portion and has an insulating film. A holding arm connects the vibrating portion and the holding portion, and include a conductive portion that is in contact with the insulating film of the holding portion in at least a region that faces the maximum displacement region of the vibrating portion. In addition, the conductive portion is electrically connected to the lower electrode or the upper electrode or is grounded.

A RF antenna comprises a quartz resonator having electrodes disposed thereon with a magnetostrictive film disposed on the quartz resonator either on, partially under or adjacent at least one of the electrodes. A RF antenna having a magnetostrictive film may be made by patterning selected portions of a top surface of the quartz wafer for deposition of electrode metal and deposition of the magnetostrictive film and depositing the electrode metal and the magnetostrictive film; temporarily bonding the quartz wafer to a handle wafer; thinning the quartz wafer to a desired thickness; etching the quartz wafer to define the outlines of at least one quartz resonator bearing the electrode metal and the magnetostrictive film; patterning selected portions of a bottom surface the at least one quartz resonator for deposition of electrode metal and at least one bond pad and depositing the electrode metal and the at least one bond pad; bonding the at least one quartz resonator to a substrate wafer; and releasing the at least one quartz resonator from the handle wafer.

A laterally vibrating bulk acoustic wave (LVBAW) resonator includes a piezoelectric plate sandwiched between first and second metal layers. The second metal layer is patterned into an interdigital transducer (IDT) with comb-shaped electrodes having interlocking fingers. The width and pitch of the fingers of the electrodes determine the resonant frequency. A combined thickness of the first and second metal layers and the piezoelectric layer is less than the pitch of the interlocking fingers.

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.