A sensor system with a first semiconductor die part and with a second semiconductor die part is proposed, wherein the first semiconductor die part has a microelectromechanical sensor element, wherein the second semiconductor die part covers the microelectromechanical sensor element, wherein the second semiconductor die part has a via for electrically contacting the microelectromechanical sensor element, in particular directly. A method for producing a sensor system is also proposed.

In a first aspect, the invention relates to a method for producing a gas-filled reference chamber which is hermetically sealed. Thereby, the gas with which the reference chamber is filled is introduced via an opening in a separate coating chamber only after bonding of the wafers forming the reference chamber. The reference chamber preferably contains MEMS devices.

In another aspect, the invention relates to a photoacoustic gas sensor comprising such a reference chamber within which a MEMS sensor is present.

Micromachined ultrasonic transducers integrated with complementary metal oxide semiconductor (CMOS) substrates are described, as well as methods of fabricating such devices. Fabrication may involve two separate wafer bonding steps. Wafer bonding may be used to fabricate sealed cavities in a substrate. Wafer bonding may also be used to bond the substrate to another substrate, such as a CMOS wafer. At least the second wafer bonding may be performed at a low temperature.

A microelectromechanical device having a first substrate of semiconductor material and a second substrate of semiconductor material having a bonding recess delimited by projecting portions, monolithic therewith. The bonding recess forms a closed cavity with the first substrate. A bonding structure is arranged within the closed cavity and is bonded to the first and second substrates. A microelectromechanical structure is formed in a substrate chosen between the first and second substrates. The device is manufactured by forming the bonding recess in a first wafer; depositing a bonding mass in the bonding recess, the bonding mass having a greater depth than the bonding recess; and bonding the two wafers.

A sensor device is constructed to maintain a high glass strength to avoid the glass failure at low burst pressure, resulting from the sawing defects located in the critical high stress area of the glass pedestal as one of the materials used for construction of the sensor. This is achieved by forming polished recess structures in the critical high stress areas of the sawing street area. The sensor device is also constructed to have a robust bonding with the die attach material by creating a plurality of micro-posts on the mounting surface of the glass pedestal.

Some embodiments are directed to techniques for building single layer or multi-layer structures on dielectric or partially dielectric substrates. Certain embodiments deposit seed layer material directly onto substrate materials while others use an intervening adhesion layer material. Some embodiments use different seed layer and/or adhesion layer materials for sacrificial and structural conductive building materials. Some embodiments apply seed layer and/or adhesion layer materials in what are effectively selective manners while others apply the materials in blanket fashion. Some embodiments remove extraneous material via planarization operations while other embodiments remove the extraneous material via etching operations. Other embodiments are directed to the electrochemical fabrication of multilayer mesoscale or microscale structures which are formed using at least one conductive structural material, at least one conductive sacrificial material, and at least one dielectric material. In some embodiments the dielectric material is a UV-curable photopolymer.

Micromachined ultrasonic transducers integrated with complementary metal oxide semiconductor (CMOS) substrates are described, as well as methods of fabricating such devices. Fabrication may involve two separate wafer bonding steps. Wafer bonding may be used to fabricate sealed cavities in a substrate. Wafer bonding may also be used to bond the substrate to another substrate, such as a CMOS wafer. At least the second wafer bonding may be performed at a low temperature.

A method of making a flowcell includes bonding a first surface of an organic solid support to a surface of a first inorganic solid support via a first bonding layer, wherein the organic solid support includes a plurality of elongated cutouts. The method further includes bonding a surface of a second inorganic solid support to a second surface of the organic solid support via a second bonding layer, so as to form the flowcell. The formed flowcell includes a plurality of channels defined by the surface of the first inorganic solid support, the surface of the second inorganic solid support, and walls of the elongated cutouts.

A method of fabricating a semiconductor device, includes, in part, growing a first layer of oxide on a surface of a first semiconductor substrate, forming a layer of insulating material on the oxide layer, patterning and etching the insulating material and the first oxide layer to form a multitude of oxide-insulator structures and further to expose the surface of the semiconductor substrate, growing a second layer of oxide in the exposed surface of the semiconductor substrate, and removing the second layer of oxide thereby to form a cavity in which a MEMS device is formed. The process of growing oxide in the exposed surface of the cavity and removing this oxide may be repeated until the cavity depth reaches a predefined value. Optionally, a multitude of bump stops is formed in the cavity.

MEMS device for low resistance applications are disclosed. In a first aspect, the MEMS device comprises a MEMS wafer including a handle wafer with one or more cavities containing a first surface and a second surface and an insulating layer deposited on the second surface of the handle wafer. The MEMS device also includes a device layer having a third and fourth surface, the third surface bonded to the insulating layer of the second surface of handle wafer; and a metal conductive layer on the fourth surface. The MEMS device also includes CMOS wafer bonded to the MEMS wafer. The CMOS wafer includes at least one metal electrode, such that an electrical connection is formed between the at least one metal electrode and at least a portion of the metal conductive layer.