A cover for an infrared detector and a method of fabricating the cover are disclosed. The cover comprises a wafer comprising a material such as silicon that transmits infrared radiation. The wafer has a first surface and a second surface opposite the first surface. An antireflective region is formed in the wafer to enhance transmission of infrared radiation through the cover. The antireflective region comprises a first plurality of antireflective elements such as moth-eyes formed in the first surface. The first plurality of antireflective elements are sized and shaped and arranged relative to one another to form a region of graded refractive index at the first surface so as to reduce the amount of infrared radiation reflected by the cover at the antireflective region. The cover comprises a wall extending from the first surface and surrounding the antireflective region. The wall comprises a plurality of layers of material deposited on the wafer so that, when the cover is bonded to a sensor substrate via the wall, a cavity is formed that encapsulates a sensor region of the sensor substrate. The depth of the cavity may be adjusted by depositing the plurality of layers of material with a combined thickness equivalent to the desired depth of the cavity. A second plurality of antireflective elements may be formed in the second surface to enhance the antireflective properties of the antireflective region.

In described examples, apparatus includes a first substrate that delimits a surface of a cavity and a bondline structure arranged along a periphery of the cavity, where the bondline structure extends from the first substrate, and the bondline structure configured to bond with an interposer arranged on a second substrate. The apparatus also includes a diffusion barrier on the first substrate, the diffusion barrier configured to contact the interposer and impede a contaminant against migrating from the bondline structure and entering the cavity.

A method is provided that includes forming a first metal layer of a seal structure over a micro-electromechanical system (MEMS) structure and over a channel formed through the MEMS structure to an integrated circuit of a semiconductor structure. The first metal layer is formed at a first temperature. The method includes forming a second metal layer over the first metal layer. The second metal layer is formed at a second temperature less than the first temperature. The method includes performing a first cooling process to cool the semiconductor structure.

A method of fabricating a plurality of individual microelectromechanical transducer elements includes forming a plurality of microelectromechanical transducer elements on a wafer. Each microelectromechanical transducer element has a sensitive region with a membrane and a sensing element monitoring at least one measurand and generating an electrical signal correlated with the at least one measurand, and an electrical contact outputting the electrical signal. The method includes providing, for each microelectromechanical transducer element, a sealing structure around a sensitive region and an electrical connection connected to the electrical contact. The sealing structure and the electrical connection are made out of a reflow solder material. The method includes dicing the wafer to form individual microelectromechanical transducer elements.

A pressure sensor structure includes a sensor body including a diaphragm plate that functions as a sense electrode, a base electrode that faces the diaphragm plate, and a sidewall layer maintaining a gap between the diaphragm plate and the base electrode, and a conductive guard substrate to support the sensor body. The sidewall layer includes a guard electrode layer and upper and lower electrically insulating layers to electrically insulate the guard electrode layer. An electrically insulating layer is between the guard substrate and the sensor body to electrically insulate the guard substrate. The guard substrate is electrically connected to the guard electrode layer to function as a guard electrode together with the guard electrode layer.

A semiconductor layer having an opening and a MEMS resonator formed in the opening is disposed between first and second substrates to encapsulate the MEMS resonator. An electrical contact that extends from the opening to an exterior of the MEMS device is formed at least in part within the semiconductor layer and at least in part within the first substrate.

A MEMS device, e.g., a flexible MEMS pressure sensor, is formed by disposing a sacrificial layer, such as photoresist, on a substrate. A first flexible support layer is disposed on the substrate, and a first conductive layer is disposed over a portion of the first support layer. A liquid or gel separator, e.g., silicone oil, is disposed on an internal region of the first conductive layer. A second flexible support layer encapsulates the first conductive layer and the separator. A second conductive layer disposed over the second support layer at least partially overlaps the first conductive layer and forms a parallel plate capacitor. A third flexible support layer encapsulates the second conductive layer and second support layer. Soaking the sensor in hot water releases the sensor from the sacrificial layer.

A semiconductor sensor device is assembled using a lead frame having a flag surrounded by lead fingers. A pressure sensor die is mounted on the flag and electrically connected to the leads. Prior to encapsulation, a pre-formed block of gel material is placed over the sensor region on the die. Encapsulation is performed and mold compound covers the pressure sensor die and the bond wires. Mold compound covering the gel block may be removed. Additionally, a trench may be formed around an upper portion of the gel block so that the lateral sides of the gel block are at least partially exposed.

An electronic assembly, including an encasement joined from at least two casing parts, wherein at least one gap region between two mutually adjoining casing parts is hermetically sealed by a metal layer that is electrodeposited onto the sections of the adjoining casing parts abutting the gap region and bridges the gap region.

A surface mounting device has one body of semiconductor material such as an ASIC, and a package surrounding the body. The package has a base region carrying the body, a cap and contact terminals. The base region has a Young's modulus lower than 5 MPa. For forming the device, the body is attached to a supporting frame including contact terminals and a die pad, separated by cavities; bonding wires are soldered to the body and to the contact terminals; an elastic material is molded so as to surround at least in part lateral sides of the body, fill the cavities of the supporting frame and cover the ends of the bonding wires on the contact terminals; and a cap is fixed to the base region. The die pad is then etched away.