Multiple degenerately-doped silicon layers are implemented within resonant structures to control multiple orders of temperature coefficients of frequency.

A semiconductor layer having an opening and a MEMS resonator formed in the opening is disposed between first and second substrates to encapsulate the MEMS resonator. An electrical contact that extends from the opening to an exterior of the MEMS device is formed at least in part within the semiconductor layer and at least in part within the first substrate.

Multiple degenerately-doped silicon layers are implemented within resonant structures to control multiple orders of temperature coefficients of frequency.

A micromechanical structure is described, including: at least one elastically deformable first area, which includes a defined piezoelectrically doped second area, at least in sections; at least one fourth area, into which the electrical charges generated in the second area may be conducted; and at least one third area connected electrically to the second and fourth area, in which an electrical current flowing through is convertible into thermal energy.

Multiple degenerately-doped silicon layers are implemented within resonant structures to control multiple orders of temperature coefficients of frequency.

A semiconductor layer having an opening and a MEMS resonator formed in the opening is disposed between first and second substrates to encapsulate the MEMS resonator. An electrical contact that extends from the opening to an exterior of the MEMS device is formed at least in part within the semiconductor layer and at least in part within the first substrate.

Multiple degenerately-doped silicon layers are implemented within resonant structures to control multiple orders of temperature coefficients of frequency.

A semiconductor layer having an opening and a MEMS resonator formed in the opening is disposed between first and second substrates to encapsulate the MEMS resonator. An electrical contact that extends from the opening to an exterior of the MEMS device is formed at least in part within the semiconductor layer and at least in part within the first substrate.

A method of fabricating a capacitive micromachined ultrasonic transducer (CMUT) according to one aspect of the present invention may include forming, on a semiconductor substrate, a first region implanted with impurity ions at a first average concentration and a second region implanted with no impurity ions or implanted with the impurity ions at a second average concentration lower than the first average concentration, forming an insulating layer by oxidizing the semiconductor substrate wherein the insulating layer includes a first oxide layer having a first thickness on at least a part of the first region and a second oxide layer having a second thickness smaller than the first thickness on at least a part of the second region, and forming a membrane layer on the insulating layer such that a gap is defined between the second oxide layer and the membrane layer.

A semiconductor layer having an opening and a MEMS resonator formed in the opening is disposed between first and second substrates to encapsulate the MEMS resonator. An electrical contact that extends from the opening to an exterior of the MEMS device is formed at least in part within the semiconductor layer and at least in part within the first substrate.