Accelerometer including a decoupling structure for fixing the accelerometer on a package and a MEMS sensor chip for measuring an acceleration. The chip is supported by the decoupling structure and includes a sensor wafer layer of a semiconductor material. The decoupling structure forms a bottom portion for fixing the decoupling structure on the package and a top portion fixed to the sensor wafer layer so that the chip is arranged above the decoupling structure. A width of the top portion in a planar direction is smaller than a width of the bottom portion and/or the sensor wafer layer in the planar direction. The decoupling structure is made of the same semiconductor material as the sensor wafer layer. The centre point of the top portion is arranged in a central region of the bottom portion. The chip includes a hermetically closed cavity which includes a seismic mass of the chip.

A method of manufacturing a dielectric barrier discharge (DBD) structure includes forming a patterned electrode layer around an outer perimeter of a substrate composed of a dielectric material. The patterned electrode layer includes multiple electrodes around the outer perimeter of the substrate and gaps between adjacent electrodes. The method further includes depositing a dielectric layer over at least a first region of the patterned electrode layer to form a DBD region of the DBD structure.

An ultrasonic transducer device includes a patterned film stack disposed on first regions of a substrate, the patterned film stack including a metal electrode layer and a bottom cavity layer formed on the metal electrode layer. The ultrasonic transducer device further includes a planarized insulation layer disposed on second regions of the substrate layer, a cavity formed in a membrane support layer and a CMP stop layer, the CMP stop layer including a top layer of the patterned film stack and the membrane support layer formed over the patterned film stack and the planarized insulation layer. The ultrasonic transducer device also includes a membrane bonded to the membrane support layer. The CMP stop layer underlies portions of the membrane support layer but not the cavity.

A method including fusion bonding a handle wafer to a first side of a device wafer. The method further includes depositing a hardmask on a second side of the device wafer, wherein the second side is planar. An etch stop layer is deposited over the hardmask and an exposed portion of the second side of the device wafer. A dielectric layer is formed over the etch stop layer. A via is formed within the dielectric layer. The via is filled with conductive material. A eutectic bond layer is formed over the conductive material. Portions of the dielectric layer uncovered by the eutectic bond layer is etched to expose the etch stop layer. The exposed portions of the etch stop layer is etched. A micro-electro-mechanical system (MEMS) device pattern is etched into the device wafer.

A preclean process may be omitted from a eutectic bonding sequence. To remove oxide from one or more surfaces of a device wafer of a micro-electromechanical-system (MEMS) structure, a duration of an acid-based etch process in the eutectic bonding sequence may be increased relative to the duration of the acid-based etch process when the preclean process is performed. The increased duration of the acid-based etch process enables the acid-based etch process to remove the oxide from the one or more surfaces of the device wafer without the use of a preceding preclean process. This reduces the complexity and cycle time of the eutectic bonding sequence, reduces the risk of stiction between suspended mechanical components of the MEMS structure, and/or reduces the likelihood that the MEMS structure may be rendered defective or inoperable during manufacturing, which increases process yield.

Representative implementations of techniques and devices provide seals for sealing the joints of bonded microelectronic devices as well as bonded and sealed microelectronic assemblies. Seals are disposed at joined surfaces of stacked dies and wafers to seal the joined surfaces. The seals may be disposed at an exterior periphery of the bonded microelectronic devices or disposed within the periphery using the various techniques.

An ultrasound transducer device includes an electrode, a membrane, and vias. The membrane is separated from the electrode by a cavity between the membrane and the electrode. The vias electrically connect the electrode to a substrate disposed on an opposite side of the electrode from a side facing the membrane. The vias are disposed in the ultrasound transducer device such that greater than 50% of the vias overlap with the cavity in a plan view.

The present disclosure provides a packaging method, including: providing a first semiconductor substrate; forming a bonding region on the first semiconductor substrate, wherein the bonding region of the first semiconductor substrate includes a first bonding metal layer and a second bonding metal layer; providing a second semiconductor substrate having a bonding region, wherein the bonding region of the second semiconductor substrate includes a third bonding layer; and bonding the first semiconductor substrate to the second semiconductor substrate by bringing the bonding region of the first semiconductor substrate in contact with the bonding region of the second semiconductor substrate; wherein the first and third bonding metal layers include copper (Cu), and the second bonding metal layer includes Tin (Sn). An associated packaging structure is also disclosed.

An ultrasound transducer device includes an electrode, a membrane, and vias. The membrane is separated from the electrode by a cavity between the membrane and the electrode. The vias electrically connect the electrode to a substrate disposed on an opposite side of the electrode from a side facing the membrane. The vias are disposed in the ultrasound transducer device such that greater than 50% of the vias overlap with the cavity in a plan view.

Certain embodiments of the present disclosure relate to a sensor assembly including a substrate having an outer region, an inner region, and a middle region between the outer region and the inner region. The substrate further includes electrical contact pads on at least the inner region. The sensor assembly further includes a housing coupled to the substrate at the middle region or the outer region to provide a hermetic seal. The sensor assembly further includes a sensor die bonded to the substrate at the inner region. A metal bond bonds electrodes of the sensor die to the electrical contact pads. The metal bond includes platinum, and/or one or more metals selected from tin, indium, copper, aluminum, and/or nickel.