A quartz crystal unit comprising a quartz crystal resonator having a base portion, and first and second tuning fork arms connected to the base portion, the base portion having a length less than 0.5 mm and greater than a spaced-apart distance between the first and second tuning fork arms, each of the first and second tuning fork arms having a width less than 0.1 mm and a length less than 1.56 mm, and a plurality of different widths including a first width and a second width greater than the first width, at least one groove being formed in at least one of opposite main surfaces of each of the first and second tuning fork arms so that a length of the at least one groove is within a range of 0.3 mm to 0.79 mm, the quartz crystal resonator being housed in a case, and a lid being connected to the case.

The present description concerns a clock signal generation device (902) comprising: a microelectromechanical resonant element (504); and at least one nanoelectromechanical transduction element (512).

MEMS based sensors, particularly capacitive sensors, potentially can address critical considerations for users including accuracy, repeatability, long-term stability, ease of calibration, resistance to chemical and physical contaminants, size, packaging, and cost effectiveness. Accordingly, it would be beneficial to exploit MEMS processes that allow for manufacturability and integration of resonator elements into cavities within the MEMS sensor that are at low pressure allowing high quality factor resonators and absolute pressure sensors to be implemented. Embodiments of the invention provide capacitive sensors and MEMS elements that can be implemented directly above silicon CMOS electronics.

The invention relates to a microelectromechanical resonator device comprising a support structure and a semiconductor resonator plate doped to a doping concentration with an n-type doping agent and being capable of resonating in a width-extensional resonance mode. In addition, there is at least one anchor suspending the resonator plate to the support structure and an actuator for exciting the width-extensional resonance mode into the resonator plate. According to the invention, the resonator plate is doped to a doping concentration of 1.2*10.sup.20 cm.sup.−3 or more and has a shape which, in combination with said doping concentration and in said width-extensional resonance mode, provides the second order temperature coefficient of frequency (TCF.sub.2) to be 12 ppb/C.sup.2 or less at least at one temperature. Several practical implementations are presented.

A bulk-acoustic-mode MEMS resonator has a first portion with a first physical layout, and a layout modification feature. The resonant frequency is a function of the physical layout, which is designed such that the frequency variation is less than 150 ppm for a variation in edge position of the resonator shape edges of 50 nm. This design combines at least two different layout features in such a way that small edge position variations (resulting from uncontrollable process variation) have negligible effect on the resonant frequency.

Embodiments of the invention include a filtering device that includes a first electrode, a piezoelectric material in contact with the first electrode, and a second electrode in contact with the piezoelectric material. The piezoelectric filtering device expands and contracts laterally in a plane of an organic substrate in response to application of an electrical signal between the first and second electrodes.

A method of making a temperature-compensated resonator is presented. The method comprises the steps of: (a) providing a substrate including a device layer; (b) replacing material from the device layer with material having an opposite temperature coefficient of elasticity (TCE) along a pre-determined region of high strain energy density for the resonator; (c) depositing a capping layer over the replacement material; and (d) etch-releasing the resonator from the substrate. The resonator may be a part of a micro electromechanical system (MEMS).

A resonator is provided that includes a vibration part, a frame, and a support arm. The vibration part includes an Si substrate that has a principal surface with a width W in an X-axis direction and a length L in a Y-axis direction. The vibration part is configured to vibrate mainly in a contour vibration mode. The support arm extends in the Y-axis direction and connects the frame to one of two ends in the Y-axis direction of the vibration part. When the principal surface of the Si substrate is viewed in a plan view, the width W is at its maximum Wmax at a point in the Y-axis direction and decreases with increasing proximity to the one of the two end portions in the Y-axis direction of the vibration part and with increasing proximity to the other end portion in the Y-axis direction of the vibration part.

A resonator that includes a rectangular vibrating portion having first and second pairs of sides that provides contour vibration. A frame surrounds a periphery of the vibrating portion and a first holding unit between the frame and one of the first sides and includes a first arm substantially in parallel to the vibrating portion, multiple second arms connecting the first arm with the vibrating portion, and a third arm connecting the first arm with the frame. A first connection line is on the first arm; a first terminal is on the frame; three or more electrodes are on the vibrating portion; and multiple first extended lines are on the second arms and connect first and second electrodes with the first connection line. The first extended lines are connected to the first connection line, which is electrically connected to the first terminal.

Embodiments of the invention include a filtering device that includes a first electrode, a piezoelectric material in contact with the first electrode, and a second electrode in contact with the piezoelectric material. The piezoelectric filtering device expands and contracts laterally in a plane of an organic substrate in response to application of an electrical signal between the first and second electrodes.