A transducer includes a first piezoelectric layer; and a second piezoelectric layer that is above the first piezoelectric layer; wherein the second piezoelectric layer is a more compressive layer with an average stress that is less than or more compressive than an average stress of the first piezoelectric layer.

A method of forming at least one Micro-Electro-Mechanical System (MEMS) includes forming a beam structure and an electrode on an insulator layer, remote from the beam structure. The method further includes forming at least one sacrificial layer over the beam structure, and remote from the electrode. The method further includes forming a lid structure over the at least one sacrificial layer and the electrode. The method further includes providing simultaneously a vent hole through the lid structure to expose the sacrificial layer and to form a partial via over the electrode. The method further includes venting the sacrificial layer to form a cavity. The method further includes sealing the vent hole with material. The method further includes forming a final via in the lid structure to the electrode, through the partial via.

Provided is a method including at least the thermal treatment step of thermally treating a SOI substrate having a first silicon layer at a first temperature that the diffusion flow rate of an interstitial silicon atom in a silicon single crystal is higher than the diffusion flow rate of an interstitial oxygen atom and the processing step of processing the SOI substrate after the thermal treatment step to obtain a displacement enlarging mechanism.

A method of manufacturing a semiconductor structure includes providing a first substrate, disposing and patterning a plate over the first substrate, disposing a first sacrificial oxide layer over the plate, forming a plurality of recesses over a surface of the first sacrificial oxide layer, disposing and patterning a membrane over the first sacrificial oxide layer, disposing a second sacrificial oxide layer to surround the membrane and cover the first sacrificial oxide layer; and forming a plurality of conductive plugs passing through the plate or the membrane, wherein the plate includes a semiconductive member and a tensile member, and the semiconductive member is disposed within the tensile member.

A method for manufacturing a MEMS device is disclosed. Moreover a MEMS device and a module including a MEMS device are disclosed. An embodiment includes a method for manufacturing MEMS devices includes forming a MEMS stack over a first main surface of a substrate, forming a polymer layer over a second main surface of the substrate and forming a first opening in the polymer layer and the substrate such that the first opening abuts the MEMS stack.

A method of forming a Micro-Electro-Mechanical System (MEMS) includes forming a lower electrode on a first insulator layer within a cavity of the MEMS. The method further includes forming an upper electrode over another insulator material on top of the lower electrode which is at least partially in contact with the lower electrode. The forming of the lower electrode and the upper electrode includes adjusting a metal volume of the lower electrode and the upper electrode to modify beam bending.

A semiconductor structure includes a first device and a second device. The first device includes a plate including a plurality of apertures; a membrane disposed opposite to the plate and including a plurality of corrugations, and a conductive plug extending through the plate and the membrane. The second device includes a substrate and a bond pad disposed over the substrate, wherein the conductive plug is bonded with the bond pad to integrate the first device with the second device, and the plate includes a semiconductive member and a tensile member, and the semiconductive member is disposed within the tensile member.

A method of forming a Micro-Electro-Mechanical System (MEMS) includes forming a lower electrode on a first insulator layer within a cavity of the MEMS. The method further includes forming an upper electrode over another insulator material on top of the lower electrode which is at least partially in contact with the lower electrode. The forming of the lower electrode and the upper electrode includes adjusting a metal volume of the lower electrode and the upper electrode to modify beam bending.

A method of forming a Micro-Electro-Mechanical System (MEMS) includes forming a lower electrode on a first insulator layer within a cavity of the MEMS. The method further includes forming an upper electrode over another insulator material on top of the lower electrode which is at least partially in contact with the lower electrode. The forming of the lower electrode and the upper electrode includes adjusting a metal volume of the lower electrode and the upper electrode to modify beam bending.

A method of forming at least one Micro-Electro-Mechanical System (MEMS) includes patterning a wiring layer to form at least one fixed plate and forming a sacrificial material on the wiring layer. The method further includes forming an insulator layer of one or more films over the at least one fixed plate and exposed portions of an underlying substrate to prevent formation of a reaction product between the wiring layer and a sacrificial material. The method further includes forming at least one MEMS beam that is moveable over the at least one fixed plate. The method further includes venting or stripping of the sacrificial material to form at least a first cavity.