A method for adjusting a resonant frequency of a resonator without impairing piezoelectricity that includes preparing a lower lid; arranging a substrate with a lower surface that faces the lower lid and forming a first electrode layer, a piezoelectric film, and a second electrode layer on an upper surface of the substrate. Moreover, a vibration arm is formed that bends and vibrates from the first electrode layer, the second electrode layer, and the piezoelectric film and an upper lid faces the lower lid with the resonator interposed therebetween. The method further includes adjusting a frequency of the resonator before or after arranging the upper lid by exciting the vibration arm by applying a voltage between the first electrode layer and the second electrode layer and by causing a part of the vibration arm to collide with either or both of the lower lid and the upper lid.

A resonator includes a vibration portion that has a substrate having a main surface, a lower electrode on the main surface of the substrate, a piezoelectric film on the lower electrode, and an upper electrode on the piezoelectric film. A frame surrounds at least part of the vibration portion. Opening grooves having different widths in a first direction in a plan view of the main surface are provided in a periphery of the vibration portion. In a plan view of the main surface, the upper electrode is provided so as to be spaced from an outer edge of the substrate by a gap which is along the first direction, such that a length of the gap in a region where a width of the opening groove is large is larger than a length of the gap in a region where a width of the opening groove is small.

A resonance device includes a resonator, an upper lid, and a lower lid. The resonator includes a vibration portion, a frame, and holding arms. The vibration portion includes a base and a plurality of vibration arms. The lower lid has a protruding portion protruding between two adjacent vibration arms, the protruding portion has an insulating film, the vibration arms have a weight portion that has a conductive film formed on the insulating film, and in a direction in which the plurality of vibration arms extend, a first distance between the weight portion of any one of the two adjacent vibration arms and the holding portion is less than a second distance between the weight portion and the protruding portion.

A vibration element includes: a base; a first arm continuous with the base; a second arm that is continuous with the base and is adjacent to the first arm; a first electrode disposed on the first arm, the second arm, and the base; a first piezoelectric layer that has a first polarity and that is disposed on the first electrode on the first arm; a second piezoelectric layer that has a second polarity different from the first polarity and that is disposed on the first electrode on the second arm; an insulating layer disposed on the first electrode on the base; and a second electrode disposed on the first piezoelectric layer, the second piezoelectric layer, and the insulating layer.

A vibration element includes: a base; an arm continuous with the base; a first electrode that includes a first layer of titanium nitride and a second layer containing nitrogen, titanium, and oxygen, and is disposed on the arm; an aluminum nitride layer in contact with the second layer; and a second electrode disposed on the aluminum nitride layer.

A resonator includes a vibration portion with upper and lower electrodes with a piezoelectric film disposed therebetween. Moreover, a protective film is provided to face the piezoelectric film with the upper electrode interposed therebetween and is exposed in a first region in the vibration portion. A conductive film is provided to face the piezoelectric film with the protective film interposed therebetween and is exposed in a second region that is adjacent to the first region in the vibration portion. A connection electrode is formed in the protective film to electrically connect the conductive film to the lower electrode. The upper electrode is formed such that an area of a region overlapping the conductive film is equal to or smaller than half of a total area of the conductive film and/or avoids the region overlapping the conductive film.

A resonator includes a vibrator with a base, and multiple vibrating arms extending therefrom. Moreover, a frame surrounds a periphery of the vibrating part and a holding arm couples the vibrator to the frame. The holding arm includes a pair of first support arms that are connected to the base opposite the vibrating arms and a coupling portion that couples the support arms with one another and that is connected to the frame.

A micromechanical resonator is provided that enables a smaller total package size with an acceptable quality factor for timing applications. The MEMS resonator includes a vibration portion with a base and three or more vibrating beams extending therefrom. Moreover, the MEMS resonator includes a frame that surrounds a periphery of the vibration portion and a pair of anchor between the vibrating beams for stabilizing the vibration portion within the frame. Furthermore, support beams couple the base of the vibration portion to the pair of anchors.

In a resonator is provided that suppresses a shift of a resonant frequency. The resonator includes a vibration portion that has a base with front and rear ends and multiple vibration arms with fixed ends connected to the front end of the base and that extend away from the front end. Moreover, the resonator includes a frame that at least partially surrounds the vibration portion and one or more holding arms provided between the vibration portion and the frame with first ends connected to the base and the second ends connected to a region of the frame at the front end side relative to the rear end of the base portion.

A MEMS device is provided that includes a piezoelectric film, a first electrode and a second electrode sandwiching the piezoelectric film, a protective film that covers at least part of the second electrode and having a cavity that opens part of the second electrode, a third electrode that contacts the second electrode at least in the cavity and is provided so as to cover at least part of the protective film, and a first wiring layer having a first contact portion in contact with the third electrode.