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.

A piezoelectric microelectromechanical systems diaphragm microphone can be mounted on a printed circuit board. The microphone can include a substrate with an opening between a bottom end of the substrate and a top end of the substrate. The microphone can have two or more piezoelectric film layers disposed over the top end of the substrate and defining a diaphragm structure. Each of the two or more piezoelectric film layers can have a predefined residual stress that substantially cancel each other out so that the diaphragm structure is substantially flat with substantially zero residual stress. The microphone can include one or more electrodes disposed over the diaphragm structure. The diaphragm structure is configured to deflect when the diaphragm is subjected to sound pressure via the opening in the substrate.

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 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.

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.

An actuator includes a diaphragm, a lower electrode on the diaphragm, an electromechanical transducer film on the lower electrode, and an upper electrode on the electromechanical transducer film. The diaphragm includes a first silicon oxide film having a thickness of 0.5 m or more, a silicon layer on the first silicon oxide film, a thickness of which is 3 m or more, and a second silicon oxide film on the silicon layer, a thickness of which is 0.5 m or more. A volume resistivity of the silicon layer is 10.sup.3 .Math.cm or more and 10.sup.6 .Math.cm or less.

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.