A device includes a substrate comprising a first standoff, a second standoff, a third standoff, a first cavity, a second cavity, and a bonding material covering a portion of the first, the second, and the third standoff. The first cavity is positioned between the first and the second standoffs, and the second cavity is positioned between the second and the third standoffs. The first cavity comprises a first cavity region and a second cavity region separated by a portion of the substrate extruding thereto, and wherein a depth associated with the first cavity region is greater than a depth associated with the second cavity. A surface of the first cavity is covered with a getter material.

A package structure of a micro speaker is provided. The package structure includes a substrate, a diaphragm, a coil, an etch stop layer, a carrier board, a permanent magnetic element, and package lid. The substrate has a hollow chamber. The diaphragm is suspended over the hollow chamber. The coil is embedded in the diaphragm. The etch stop layer is positioned below the coil and overlaps the coil in the direction that is perpendicular to the top surface of the diaphragm. The etch stop layer is made of a metal material. The carrier board is disposed on the bottom surface of the substrate. The permanent magnetic element is disposed on the carrier board and in the hollow chamber. The package lid is wrapped around the substrate and the diaphragm, and has a lid opening that exposes a portion of the top surface of the diaphragm.

A sensor membrane structure is provided. The sensor membrane structure includes a substrate, a first insulating layer, and a device layer. The substrate has a first surface and a second surface that is opposite to the first surface. A cavity is formed on the first surface, an opening is formed on the second surface, and the cavity communicates with the opening. The cavity and the opening penetrate the substrate in a direction that is perpendicular to the first surface. The first insulating layer is disposed on the first surface of the substrate. The device layer is disposed on the first insulating layer. The first insulating layer is disposed for protecting the sensor membrane structure from overetched and remain stable during the etching process, increasing the yield of the sensor membrane structure.

A piezoelectric microelectromechanical systems (MEMS) microphone is provided comprising a substrate including walls defining a cavity and at least one of the walls defining an anchor region, a piezoelectric film layer supported by the substrate at the anchor region such that the piezoelectric film layer is cantilevered, the piezoelectric film layer being formed to introduce differential stress between a front surface of the piezoelectric film layer oriented away from the cavity and a back surface of the piezoelectric film layer oriented towards the cavity such that the piezoelectric film layer is bent into the cavity, and an electrode disposed over the piezoelectric film layer and adjacent the anchor region. A method of manufacturing such a MEMS microphone is also provided.

A micromechanical component for a sensor device or microphone device. The micromechanical component includes a diaphragm with a diaphragm inner side to which an electrode structure is directly or indirectly connected; and a cavity that is formed at least in a volume that is exposed by at least one removed area of at least one sacrificial layer. At least one residual area made of at least one electrically insulating sacrificial layer material of the at least one sacrificial layer is also present at the micromechanical component, and including at least one insulation area made of at least one electrically insulating material that is not the same as the electrically insulating sacrificial layer material. The electrode structure is electrically insulated from the diaphragm, and/or the at least one residual area of the at least one sacrificial layer is delimited from the cavity, using the at least one insulation area.

A method includes forming an etch stop layer over a first side of a device wafer. The method also includes forming a polysilicon layer over the etch stop layer. A handle wafer is fusion bonded to the first side of the device wafer. A eutectic bond layer is formed on a second side of the device wafer. A micro-electro-mechanical system (MEMS) features are etched into the second side of the device wafer to expose the etch stop layer. The exposed etch stop layer is removed to expose the polysilicon layer. The exposed polysilicon layer is removed to expose a cavity formed between the handle wafer and the device wafer.

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.

In an embodiment, a method for manufacturing a micro-electro-mechanical systems (MEMS) transducer device includes providing a substrate body with a surface, depositing an etch-stop layer (ESL) on the surface, depositing a sacrificial layer on the ESL, depositing a diaphragm layer on the sacrificial layer and removing the sacrificial layer, wherein depositing the sacrificial layer includes depositing a first sub-layer of a first material and depositing a second sub-layer of a second material, and wherein the first material and the second material are different materials.

The disclosure relates to a method for manufacturing a planarized etch-stop layer, ESL, for a hydrofluoric acid, HF, vapor phase etching process. The method includes providing a first planarized layer on top of a surface of a substrate, the first planarized layer having a patterned and structured metallic material and a filling material. The method further includes depositing on top of the first planarized layer the planarized ESL of an ESL material with low HF etch rate, wherein the planarized ESL has a low surface roughness and a thickness of less than 150 nm, in particular of less than 100 nm.

In an embodiment, an integrated MEMS transducer device includes a substrate body having a first electrode on a substrate, an etch stop layer located on a surface of the substrate, a suspended micro-electro-mechanical systems (MEMS) diaphragm with a second electrode, an anchor structure with anchors connecting the MEMS diaphragm to the substrate body and a sacrificial layer in between the anchors of the anchor structure, the sacrificial layer including a first sub-layer of a first material, wherein the first sub-layer is arranged on the etch stop layer, a second sub-layer of a second material, wherein the second sub-layer is arranged on the first sub-layer, and wherein the first and the second material are different materials.