A method of forming an ultrasonic transducer device includes forming and patterning a film stack over a substrate, the film stack comprising a metal electrode layer and a chemical mechanical polishing (CMP) stop layer formed over the metal electrode layer; forming an insulation layer over the patterned film stack; planarizing the insulation layer to the CMP stop layer; measuring a remaining thickness of the CMP stop layer; and forming a membrane support layer over the patterned film stack, wherein the membrane support layer is formed at thickness dependent upon the measured remaining thickness of the CMP stop layer, such that a combined thickness of the CMP stop layer and the membrane support layer corresponds to a desired transducer cavity depth.

The invention provides a MEMS microphone. The MEMS microphone includes a substrate, having a first opening. A dielectric layer is disposed on the substrate, wherein the dielectric layer has a second opening aligned to the first opening. A diaphragm is disposed within the second opening of the dielectric layer, wherein a peripheral region of the diaphragm is embedded into the dielectric layer at sidewall of the second opening. A backplate layer is disposed on the dielectric layer and covering over the second opening. The backplate layer includes a plurality of acoustic holes arranged into a regular array pattern. The regular array pattern comprises a pattern unit, the pattern unit comprises one of the acoustic holes as a center hole, and peripheral holes of the acoustic holes surrounding the center hole with a same pitch to the center hole.

A method produces a micromechanical sensor element having a first electrode and a second electrode, wherein electrode wall surfaces of the first and the second electrodes are situated opposite one another in a first direction and form a capacitance, wherein one of the first electrode or the second electrode is movable in a second direction, in response to a variable to be detected, and a second one of the first electrode and the second electrode is fixed. The method includes producing a cavity in a semiconductor substrate, the cavity being closed by a doped semiconductor layer; producing the first and the second electrodes in the semiconductor layer, including modifying the electrode wall surface of the first electrode in order to have a smaller extent in the second direction than the electrode wall surface of the second electrode.

A diaphragm for use in a transducer, the diaphragm including a flexible layer configured to deflect in response to changes in a differential pressure. The flexible layer includes a lattice grid. The lattice grid includes a first plurality of substantially elongate openings oriented along an axis and a second plurality of substantially elongate openings extending generally parallel to the axis. The second plurality of openings is substantially offset from the first plurality of openings in a direction substantially parallel to the axis. The first plurality of openings and the second plurality of openings define a first plurality of spaced apart grid beams extending between and substantially parallel to the axis and a second plurality of spaced apart grid beams extending substantially perpendicular to the axis. The second plurality of grid beams is configured to connect adjacent ones of the first plurality of grid beams.

A piezoelectric microelectromechanical systems device is provided, having a first piezoelectric layer, a first metal layer including a first metal, a second metal layer including a second metal, the first and second metals having different properties to compensate deflection due to thermal stress of any or all of the piezoelectric layer, the first metal layer, and second metal layer and a substrate including at least one wall defining a cavity and the at least one wall supporting the layers. The method for making the piezoelectric microelectromechanical systems device is also provided.

A semiconductor device and method of manufacturing the device that includes a capacitive micromachined ultrasonic transducer (CMUT). The CMUT includes an integrated circuit substrate, and a sensing electrode positioned on the integrated substrate. The sensing electrode includes a sidewall that forms a wall of an isolation trench adjacent to the sensing electrode, and is patterned before covering dielectric layers are deposited. After patterning of the sensing electrode, one or more dielectric layers are patterned, with one dielectric layer patterned on the sensing electrode and sidewall, and which has a thickness corresponding to the surface roughness of the sensing electrode. The CMUT further includes a membrane positioned above the sensing electrode forming a cavity therein.

A MEMS microphone according to an embodiment comprises a substrate including an air chamber in a central portion, a back-plate disposed above the substrate and including a plurality of penetration holes through which a sound wave passes, and a vibration membrane disposed between the back-plate and the substrate, forming compressive residual stress, having a base form convexly bent toward the back-plate, and configured to vibrate a sound pressure transferred through the plurality of penetration holes.

Various embodiments of the present disclosure are directed towards a microelectromechanical systems (MEMS) structure including an epitaxial layer overlying a MEMS substrate. The MEMS substrate comprises a moveable element arranged over a carrier substrate. The epitaxial layer has a higher doping concentration than the MEMS substrate. A plurality of contacts overlies the epitaxial layer. A first subset of the plurality of contacts overlies the moveable element. The plurality of contacts respectively has an ohmic contact with the epitaxial layer.

A ultrasonic transducer device includes a transducer bottom electrode layer disposed over a substrate, and a plurality of vias that electrically connect the bottom electrode layer with the substrate, wherein substantially an entirety of the plurality of vias are disposed directly below a footprint of a transducer cavity. Alternatively, the transducer bottom electrode layer includes a first metal layer in contact with the plurality of vias and a second metal layer formed on the first metal layer, the first metal layer including a same material as the plurality of vias.

An MEMS having a layered structure includes a cavity disposed in the layered structure and fluidically coupled to an external environment of the layered structure through at least one opening in the layered structure. The MEMS includes an interaction structure movably disposed in a first MEMS plane and in the cavity along a plane direction and configured to interact with a fluid in the cavity, wherein movement of the interaction structure is causally related to movement of the fluid through the at least one opening. The MEMS further includes an active structure disposed in a second MEMS perpendicular to the plane direction, the active structure mechanically coupled to the insulation structure and configured such that an electrical signal at an electrical contact of the active structure is causally related to a deformation of the active structure, wherein the deformation of the active structure is causally related to movement of the fluid.