The disclosure relates to a method for manufacturing recessed micromechanical structures in a MEMS device wafer. First vertical trenches in the device wafer define the horizontal dimensions of both level and recessed structures. The horizontal face of the device wafer and the vertical sidewalls of the first vertical trenches are then covered with a self-supporting etching mask which is made of a self-supporting mask material, which is sufficiently rigid to remain standing vertically in the location where it was deposited even as the sidewall upon which it was deposited is etched away. Recess trenches are then etched under the protection of the self-supporting mask. The method allows a spike-preventing aggressive etch to be used for forming the recess trenches, without harming the sidewalls in the first vertical trenches.

An embodiment of an integrated microphone structure. The integrated microphone structure includes a first silicon substrate patterned as a first plate. A silicon oxide layer formed on one side of the first silicon substrate. A second silicon substrate bonded to the first substrate through the silicon oxide layer such that the silicon oxide layer is sandwiched between the first and second silicon substrates. A diaphragm secured on the silicon oxide layer and disposed between the first and second silicon substrates such that the first plate and the diaphragm are configured to form a capacitive microphone.

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 micro electro mechanical system (MEMS) microphone includes a base including a port extending through the base, a shim assembly, an ingress protection element, and a MEMS device. The shim assembly is disposed on the base and over the port. The shim assembly has a plurality of walls that form a hollow interior cavity. The shim assembly also has a top surface and a bottom surface coupled to the base. The ingress protection element extends over and is coupled to the top of the shim assembly to enclose the cavity of the shim assembly. The shim assembly elevates the ingress protection element above the base and is effective to prevent the passage of contaminants there through. The MEMS device includes a diaphragm and a back plate and is disposed over the ingress protection element.

The invention provides a method for manufacturing a MEMS microphone, including the steps of: providing a base and preparing a first diaphragm on a first surface of the base; preparing a back plate on a surface of the first diaphragm opposite to the first surface; forming a first gap between the first diaphragm and the back plate; preparing a second diaphragm; forming a second gap between the second diaphragm and the back plate; preparing electrodes; forming a back cavity by etching the surface opposite to the first surface.

In described examples, a cavity is formed between a substrate and a cap. One or more access holes are formed through the cap for removing portions of a sacrificial layer from within the cavity. A cover is supported by the cap, where the cover is for occulting the one or more access holes along a perspective. An encapsulant seals the cavity, where the encapsulant encapsulates the cover and the one or more access holes.

Systems and methods that protect CMOS layers from exposure to a release chemical are provided. The release chemical is utilized to release a micro-electro-mechanical (MEMS) device integrated with the CMOS wafer. Sidewalls of passivation openings created in a complementary metal-oxide-semiconductor (CMOS) wafer expose a dielectric layer of the CMOS wafer that can be damaged on contact with the release chemical. In one aspect, to protect the CMOS wafer and prevent exposure of the dielectric layer, the sidewalls of the passivation openings can be covered with a metal barrier layer that is resistant to the release chemical. Additionally, or optionally, an insulating barrier layer can be deposited on the surface of the CMOS wafer to protect a passivation layer from exposure to the release chemical.

A micro electro mechanical system (MEMS) microphone includes a base including a port extending through the base, a shim assembly, an ingress protection element, and a MEMS device. The shim assembly is disposed on the base and over the port. The shim assembly has a plurality of walls that form a hollow interior cavity. The shim assembly also has a top surface and a bottom surface coupled to the base. The ingress protection element extends over and is coupled to the top of the shim assembly to enclose the cavity of the shim assembly. The shim assembly elevates the ingress protection element above the base and is effective to prevent the passage of contaminants there through. The MEMS device includes a diaphragm and a back plate and is disposed over the ingress protection element.

In described examples, a cavity is formed between a substrate and a cap. One or more access holes are formed through the cap for removing portions of a sacrificial layer from within the cavity. A cover is supported by the cap, where the cover is for occulting the one or more access holes along a perspective. An encapsulant seals the cavity, where the encapsulant encapsulates the cover and the one or more access holes.

A method for manufacturing a MEMS device includes a hole forming step of forming a plurality of holes concaved from a principal surface in a substrate material including a semiconductor, a connecting-hollow-portion forming step of forming a connecting hollow portion that connects the plurality of holes together, and a movable-portion forming step of, by partially moving the semiconductor of the substrate material so as to close at least one part of the plurality of holes, forming a hollow portion that exists inside the substrate material and a movable portion that coincides with the hollow portion when viewed in a thickness direction of the substrate material.