A method of manufacturing a plurality of resonators, each formed by a membrane sealing a cavity, includes forming a plurality of cavities starting from one face called the front face of a support substrate, the plurality of cavities comprising central cavities and peripheral cavities arranged around the assembly formed by the central cavities, and forming central membranes and peripheral membranes covering the central cavities and peripheral cavities, respectively, by the transfer of a coverage film on the front face of the support substrate. At least part of the peripheral membranes is removed.

A dual-output microelectromechanical system (MEMS) resonator can be operated selectively and concurrently in an in-plane mode of vibration and an out-of-plane mode of vibration to obtain, respectively, a first electrical signal having a first frequency and a second electrical signal having a second frequency that is less than the first frequency. The first and second electrical signals are mixed to obtain a third electrical signal having a third frequency, where the third frequency is proportional to a temperature of the MEMS resonator. The temperature is determined based on the third frequency. Values of the first and second frequencies can be adjusted based on the determined temperature to compensate for frequency deviations due to temperature deviations. Also described herein are methods and systems for determining the temperature of the dual-output MEMS and for performing frequency compensation, as well as a method of manufacturing the dual-output MEMS.

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.

Provided is a semiconductor chip, including: a semiconductor substrate; a thin film formed on the semiconductor substrate, the thin film having internal stress; and a semiconductor device formed on the semiconductor substrate that has the thin film formed thereon, wherein the semiconductor chip warps due to the internal stress of the thin film.

A piezoelectric micromachined ultrasonic transducer (PMUT) includes a substrate, a stopper, and a membrane, where the substrate and the stopper are composed of same single-crystalline material. The substrate has a cavity penetrating the substrate, and the stopper protrudes from a top surface of the substrate and surrounds the edge of the cavity. The membrane is disposed over the cavity and attached to the stopper.

Various embodiments of the present disclosure are directed towards a semiconductor device. The semiconductor device includes an interconnect structure disposed over a semiconductor substrate. A dielectric structure is disposed over the interconnect structure. A plurality of cavities are disposed in the dielectric structure. A microelectromechanical system (MEMS) substrate is disposed over the dielectric structure, where the MEMS substrate comprises a plurality of movable membranes, and where the movable membranes overlie the cavities, respectively. A plurality of fluid communication channels are disposed in the dielectric structure, where each of the fluid communication channels extend laterally between two neighboring cavities of the cavities, such that each of the cavities are in fluid communication with one another.

A method of forming an ultrasonic transducer device includes forming an insulating layer having topographic features over a lower transducer electrode layer of a substrate; forming a conformal, anti-stiction layer over the insulating layer such that the conformal layer also has the topographic features; defining a cavity in a support layer formed over the anti-stiction layer; and bonding a membrane to the support layer.

A method of manufacturing an ultrasound imaging device involves forming an interposer structure, including forming a first metal material within openings through a substate and on top and bottom surfaces of the substrate, patterning the first metal material, forming a dielectric layer over the patterned first metal material, forming openings within the dielectric layer to expose portions of the patterned first metal material, filling the openings with a second metal material, forming a third metal material on the top and bottom surfaces of the substrate, and patterning the third metal material. The method further involves forming a packaging structure for an ultrasound-on-chip device, including attaching a multi-layer flex substrate to a carrier wafer, bonding a first side of an ultrasound-on-chip device to the multi-layer flex substrate, bonding a second side of the ultrasound-on-chip device to a first side of the interposer structure, and removing the carrier wafer.

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 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.