Abstract: An optical filter comprising a first substrate, a first mirror formed on the first substrate, a second substrate coupled to the first substrate, the second substrate including a concave portion, and a second mirror formed on the concave portion and facing the first mirror, wherein the first substrate includes a first portion located on the first mirror, a second portion located around the first portion, a third portion located around the second portion, and a fourth portion located around the third portion, wherein both a thickness of the second portion and a thickness of the fourth portion are equal to or smaller than a thickness of the first portion.

Abstract: A vibrator element includes a base section, vibration arms, and excitation electrodes provided to the respective vibration arms, the excitation electrodes each include a first electrode disposed on a principal surface side of the vibration arm, a second electrode disposed so as to be opposed to the first electrode, and a piezoelectric body extending between the first electrode and the second electrode, and ITO is used as at least one of the first electrode and the second electrode.

Abstract: A sensor element (a vibrator element) includes a base portion; a vibrating arm extended from the base portion; a drive unit that is provided in the vibrating arm and has a first electrode layer, a second electrode layer, and a piezoelectric body layer; a wiring having a portion that is drawn from the second electrode layer and is provided along a side surface of the piezoelectric body layer; and a terminal that is provided in the base portion and is electrically connected to the second electrode layer via the wiring.

Abstract: A vibrating piece manufacturing method includes: (a) preparing a supporting body having first and second surfaces, the first and second surfaces defining a thickness while being directed toward opposite directions, the supporting body including a base and a plurality of arms, the arms extending side-by-side in a direction orthogonal to a direction of the thickness from the base, a lower electrode film being disposed on the first surface of each of the arms, a piezoelectric film being disposed on the lower electrode films, at least one upper electrode film being disposed on the piezoelectric film, at least a part of the second surface of each of the arms being an exposed area; and (b) etching the exposed area of the second surface so as to reduce the thickness to reduce flexural rigidity of the arms with respect to the thickness direction.

Abstract: A resonator element includes: three or more resonating arms, each of the resonating arms including; a lower electrode provided on a first surface of the resonating arm, a piezoelectric film formed on the lower electrode, an upper electrode formed on the piezoelectric film, a first wiring line coupled to the lower electrode, and a second wiring line coupled to the upper electrode; and a base to which the resonating arms are connected. In the resonator element, the resonating arm vibrates in a thickness direction of the resonating arm. The resonating arms adjacent to each other vibrate in opposite directions from each other. The first surface is opposed to a second surface in the thickness direction. The second wiring line is drawn out to the second surface through side surfaces of the resonating arm so as to surround the resonating arm.

Abstract: A vibrating piece manufacturing method includes: (a) preparing a supporting body having first and second surfaces, the first and second surfaces defining a thickness while being directed toward opposite directions, the supporting body including a base and a plurality of arms, the arms extending side-by-side in a direction orthogonal to a direction of the thickness from the base, a lower electrode film being disposed on the first surface of each of the arms, a piezoelectric film being disposed on the lower electrode films, at least one upper electrode film being disposed on the piezoelectric film, at least a part of the second surface of each of the arms being an exposed area; and (b) etching the exposed area of the second surface so as to reduce the thickness to reduce flexural rigidity of the arms with respect to the thickness direction.

Abstract: A vibrator element includes a base section, vibration arms, and excitation electrodes provided to the respective vibration arms, the excitation electrodes each include a first electrode disposed on a principal surface side of the vibration arm, a second electrode disposed so as to be opposed to the first electrode, and a piezoelectric body extending between the first electrode and the second electrode, and ITO is used as at least one of the first electrode and the second electrode.

Abstract: A vibrating piece manufacturing method includes: (a) preparing a supporting body having first and second surfaces, the first and second surfaces defining a thickness while being directed toward opposite directions, the supporting body including a base and a plurality of arms, the arms extending side-by-side in a direction orthogonal to a direction of the thickness from the base, a lower electrode film being disposed on the first surface of each of the arms, a piezoelectric film being disposed on the lower electrode films, at least one upper electrode film being disposed on the piezoelectric film, at least a part of the second surface of each of the arms being an exposed area; and (b) etching the exposed area of the second surface so as to reduce the thickness to reduce flexural rigidity of the arms with respect to the thickness direction.

Abstract: Deterioration of the Q value caused by the thermoelastic effect is suppressed. Since a first depth of a first groove and a second depth of a second groove are smaller than a distance between a surface including a third surface and a surface including a fourth surface, the first and second grooves do not penetrate between the surface including the third surface and the surface including the fourth surface. In addition, the sum of the first depth of the first groove and the second depth of the second groove is greater than the distance between the third and fourth surfaces, a heat transfer path between a first expandable portion (the first surface) and a second expandable portion (the second surface) cannot be formed as a straight line. As such, the heat transfer path between the first expandable portion (the first surface) and a second expandable portion (the second surface) is made to detour to the first and second grooves and and thus be lengthened.

Abstract: A resonator element includes: three or more resonating arms, each of the resonating arms including; a lower electrode provided on a first surface of the resonating arm, a piezoelectric film formed on the lower electrode, an upper electrode formed on the piezoelectric film, a first wiring line coupled to the lower electrode, and a second wiring line coupled to the upper electrode; and a base to which the resonating arms are connected. In the resonator element, the resonating arm vibrates in a thickness direction of the resonating arm. The resonating arms adjacent to each other vibrate in opposite directions from each other. The first surface is opposed to a second surface in the thickness direction. The second wiring line is drawn out to the second surface through side surfaces of the resonating arm so as to surround the resonating arm.

Abstract: An optical filter comprising a first substrate, a first mirror formed on the first substrate, a second substrate coupled to the first substrate, the second substrate including a concave portion, and a second mirror formed on the concave portion and facing the first mirror, wherein the first substrate includes a first portion located on the first mirror, a second portion located around the first portion, a third portion located around the second portion, and a fourth portion located around the third portion, wherein both a thickness of the second portion and a thickness of the fourth portion are equal to or smaller than a thickness of the first portion.

Abstract: A vibrating piece manufacturing method includes: (a) preparing a supporting body having first and second surfaces, the first and second surfaces defining a thickness while being directed toward opposite directions, the supporting body including a base and a plurality of arms, the arms extending side-by-side in a direction orthogonal to a direction of the thickness from the base, a lower electrode film being disposed on the first surface of each of the arms, a piezoelectric film being disposed on the lower electrode films, at least one upper electrode film being disposed on the piezoelectric film, at least a part of the second surface of each of the arms being an exposed area; and (b) etching the exposed area of the second surface so as to reduce the thickness to reduce flexural rigidity of the arms with respect to the thickness direction.

Abstract: An acoustic wave device capable of exhibiting good characteristics for a prolonged period of time and a method of manufacturing an acoustic wave device are provided. An acoustic wave device of the invention includes a piezoelectric body layer having piezoelectricity and one surface, a pair of electrodes for, when electrified, inducing acoustic vibration in the piezoelectric body layer, the electrodes arranged on the one surface of the piezoelectric body layer, and a silicon dioxide layer provided in contact with the piezoelectric body layer and/or the electrodes, the silicon dioxide layer composed of silicon dioxide as its major component, wherein the silicon dioxide layer is formed by performing sputtering with a silicon dioxide target in an atmosphere of an oxygen flow rate ratio of 60% or more.

Abstract: An acoustic wave device capable of exhibiting good characteristics for a prolonged period of time and a method of manufacturing an acoustic wave device are provided. An acoustic wave device of the invention includes a piezoelectric body layer having piezoelectricity and one surface, a pair of electrodes for, when electrified, inducing acoustic vibration in the piezoelectric body layer, the electrodes arranged on the one surface of the piezoelectric body layer, and a silicon dioxide layer provided in contact with the piezoelectric body layer and/or the electrodes, the silicon dioxide layer composed of silicon dioxide as its major component, wherein the silicon dioxide layer is formed by performing sputtering with a silicon dioxide target in an atmosphere of an oxygen flow rate ratio of 60% or more.