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.

The application describes MEMS transducer having a flexible membrane and which seeks to alleviate and/or redistribute stresses within the membrane layer. A membrane having a first/active region and a second/inactive region is described.

A three dimensional (3D) micro-electro-mechanical system (MEMS) device is provided. The device comprises a central MEMS wafer, and top and bottom cap wafers. The MEMS wafer includes a MEMS structure, such as an inertial sensor. The 5 top cap wafer, the bottom cap wafer and the MEMS wafers are stacked along a stacking axis and together form at least one hermetic cavity enclosing the MEMS structure. At least one of the top cap wafer and the bottom cap wafer is a silicon-on- insulator (SOI) cap wafer comprising a cap device layer, a cap handle layer and a cap insulating layer interposed between the cap device layer and the cap handle layer. At 10 least one electrically conductive path extends through the SOI cap wafer, establishing an electrical convection between an outer electrical contact provided on the SOI cap wafer and the MEMS structure.

A MEMS sensor device package comprises a sensor assembly comprising a sensor device and a sensor circuit communicating coupled to the sensor device, The MEMS sensor device package further comprises an assembly package housing having a top member and a bottom member attached to the top member for encapsulating the sensor assembly. A passageway fluidly coupled the sensor device to attributes outside the package housing the passageway is embedded into the package housing, wherein the top member comprising a top wall and side walls, the side walls are attached to the bottom member, and the passageway is embedded into at least one of the side walls.

A coating for protecting a wafer from moisture and debris due to dicing, singulating, or handling the wafer is provided. A semiconductor sensor device comprises a wafer having a surface and at least one trench feature and the protective coating covering the trench feature. The trench feature comprises a plurality of walls and the walls are covered with the protective coating, wherein the walls of the trench feature are formed as a portion of the semiconductor sensor device. The semiconductor sensor device further comprises a patterned mask formed on the wafer before the trench feature is formed, wherein the protective coating is formed directly to the trench feature and the patterned mask. The semiconductor sensor device is selected from a group consisting of a MEMS die, a sensor die, a sensor circuit die, a circuit die, a pressure die, an accelerometer, a gyroscope, a microphone, a speaker, a transducer, an optical sensor, a gas sensor, a bolometer, a giant megnetoresistive sensor (GMR), a tunnel magnetoresistive (TMR) sensor, an environmental sensor, and a temperature sensor.

A process comprises bonding a semiconductor wafer to an inorganic wafer. The semiconductor wafer is opaque to a wavelength of light to which the inorganic wafer is transparent. After the bonding, a damage track is formed in the inorganic wafer using a laser that emits the wavelength of light. The damage track in the inorganic wafer is enlarged to form a hole through the inorganic wafer by etching. The hole terminates at an interface between the semiconductor wafer and the inorganic wafer. An article is also provided, comprising a semiconductor wafer bonded to an inorganic wafer. The semiconductor wafer is opaque to a wavelength of light to which the inorganic wafer is transparent. The inorganic wafer has a hole formed through the inorganic wafer. The hole terminates at an interface between the semiconductor wafer and the inorganic wafer.

Micro-electromechanical (MEMS) devices and methods of forming are provided. The MEMS device includes a first substrate including a first conductive feature, a first movable element positioned over the first conductive feature, a second conductive feature, and a second movable element positioned over the second conductive feature. The MEMS device also includes a cap bonded to the first substrate, where the cap and the first substrate define a first sealed cavity and a second sealed cavity. The first conductive feature and the first movable element are disposed in the first sealed cavity and the second conductive feature and the second movable element are disposed in the second sealed cavity. A pressure of the second cavity is higher than a pressure of the first sealed cavity, and an out gas layer is disposed in a recess of the cap that partially defines the second sealed cavity.

The application describes MEMS transducer structures comprising a membrane structure having a flexible membrane layer and at least one electrode layer. The electrode layer is spaced from the flexible membrane layer such that at least one air volume extends between the material of the electrode layer and the membrane layer. The electrode layer is supported relative to the flexible membrane by means of a support structure which extends between the first electrode layer and the flexible membrane layer.

A micromechanical structure in accordance with various embodiments may include: a substrate; and a functional structure arranged at the substrate; wherein the functional structure includes a functional region which is deflectable with respect to the substrate responsive to a force acting on the functional region; and wherein at least a section of the functional region has an elastic modulus in the range from about 5 GPa to about 70 GPa.

According to one embodiment, a strain and pressure sensing device includes a semiconductor circuit unit and a sensing unit. The semiconductor circuit unit includes a semiconductor substrate and a transistor. The transistor is provided on a semiconductor substrate. The sensing unit is provided on the semiconductor circuit unit, and has space and non-space portions. The non-space portion is juxtaposed with the space portion. The sensing unit further includes a movable beam, a strain sensing element unit, and first and second buried interconnects. The movable beam has fixed and movable portions, and includes first and second interconnect layers. The fixed portion is fixed to the non-space portion. The movable portion is separated from the transistor and extends from the fixed portion into the space portion. The strain sensing element unit is fixed to the movable portion. The first and second buried interconnects are provided in the non-space portion.