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.

A microelectromechanical (MEMS) resonator includes a spring-mass system having a first weight portion (M1), a second weight portion (M2), and a central spring portion (SP) in between the weight portions.

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.

A resonator that includes a substrate, an insulating film that is formed on the substrate, and vibration regions each of which is formed on the insulating film and includes lower electrodes that are formed on the insulating film, a piezoelectric film that is formed on the lower electrodes, and an upper electrode that is formed on the piezoelectric film. At least one lower electrode of the lower electrodes that are formed on the insulating film has an electric potential that differs from an electric potential of another lower electrode such that at least one vibration region vibrates in antiphase with another vibration region. Moreover, a package seals a resonator and includes the substrate, the insulating film, and the vibration regions and includes a ground terminal for grounding the substrate.

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.

A resonator that includes a substrate, an insulating film that is formed on the substrate, and vibration regions each of which is formed on the insulating film and includes lower electrodes that are formed on the insulating film, a piezoelectric film that is formed on the lower electrodes, and an upper electrode that is formed on the piezoelectric film. At least one lower electrode of the lower electrodes that are formed on the insulating film has an electric potential that differs from an electric potential of another lower electrode such that at least one vibration region vibrates in antiphase with another vibration region. Moreover, a package seals a resonator and includes the substrate, the insulating film, and the vibration regions and includes a ground terminal for grounding the substrate.

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.

A vibration device that includes a support member, vibration arms connected to the support member and each having an n-type Si layer which is a degenerate semiconductor, and electrodes provided so as to excite the vibration arms, and silicon oxide films containing impurities in contact with a respective lower surface of the n-type Si layers of each vibration arm.

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.

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.