In a microelectromechanical system (MEMS) device, a CMOS die is affixed to a die-mounting surface and wire-bonded to electrically conductive leads, and a MEMS die is stacked on and electrically coupled to the CMOS die in a flip-chip configuration. A package enclosure envelopes the MEMS die, CMOS die and wire bonds, and exposes respective regions of the electrically conductive leads.

A pressure sensor using the MEMS device comprises an airtight ring surrounding a chamber defined by the first substrate and the second substrate. The airtight ring extends from the upper surface of the second substrate to the interface between the first substrate and the second substrate and further breaks out the interface. The pressure sensor utilizes the airtight ring to retain the airtightness of the chamber.

A method of bonding of germanium to aluminum between two substrates to create a robust electrical and mechanical contact is disclosed. An aluminum-germanium bond has the following unique combination of attributes: (1) it can form a hermetic seal; (2) it can be used to create an electrically conductive path between two substrates; (3) it can be patterned so that this conduction path is localized; (4) the bond can be made with the aluminum that is available as standard foundry CMOS process. This has the significant advantage of allowing for wafer-level bonding or packaging without the addition of any additional process layers to the CMOS wafer.

A pressure sensor using the MEMS device comprises an airtight ring surrounding a chamber defined by the first substrate and the second substrate. The airtight ring extends from the upper surface of the second substrate to the interface between the first substrate and the second substrate and further breaks out the interface. The pressure sensor utilizes the airtight ring to retain the airtightness of the chamber.

Sensor packages and manners of formation are described. In an embodiment, a sensor package includes a supporting die characterized by a recess area and a support anchor protruding above the recess area. A sensor die is bonded to the support anchor such that an air gap exists between the sensor die and the recess area. The sensor die includes a sensor positioned directly above the air gap.

A pressure sensor using the MEMS device comprises an airtight ring surrounding a chamber defined by the first substrate and the second substrate. The airtight ring extends from the upper surface of the second substrate to the surface between the first substrate and the second substrate and further breaks out the surface. The pressure sensor utilizes the airtight ring to retain the airtightness of the chamber. The manufacture method of the pressure sensor is also disclosed.

A method of bonding of germanium to aluminum between two substrates to create a robust electrical and mechanical contact is disclosed. An aluminum-germanium bond has the following unique combination of attributes: (1) it can form a hermetic seal; (2) it can be used to create an electrically conductive path between two substrates; (3) it can be patterned so that this conduction path is localized; (4) the bond can be made with the aluminum that is available as standard foundry CMOS process. This has the significant advantage of allowing for wafer-level bonding or packaging without the addition of any additional process layers to the CMOS wafer.

A MEMS device is disclosed. The MEMS device includes a first substrate. At least one structure is formed within the first substrate. The first substrate includes at least one first conductive pad thereon. The MEMS device also includes a second substrate. The second substrate includes a passivation layer. The passivation layer includes a plurality of layers. A top layer of the plurality of layers comprises an outgassing barrier layer. At least one second conductive pad and at least one electrode are coupled to the top layer. At least one first conductive pad is coupled to the at least one second conductive pad.

Sensor packages and manners of formation are described. In an embodiment, a sensor package includes a supporting die characterized by a recess area and a support anchor protruding above the recess area. A sensor die is bonded to the support anchor such that an air gap exists between the sensor die and the recess area. The sensor die includes a sensor positioned directly above the air gap.

A low-profile packaging structure for a microelectromechanical-system (MEMS) resonator system includes an electrical lead having internal and external electrical contact surfaces at respective first and second heights within a cross-sectional profile of the packaging structure and a die-mounting surface at an intermediate height between the first and second heights. A resonator-control chip is mounted to the die-mounting surface of the electrical lead such that at least a portion of the resonator-control chip is disposed between the first and second heights and wire-bonded to the internal electrical contact surface of the electrical lead. A MEMS resonator chip is mounted to the resonator-control chip in a stacked die configuration and the MEMS resonator chip, resonator-control chip and internal electrical contact and die-mounting surfaces of the electrical lead are enclosed within a package enclosure that exposes the external electrical contact surface of the electrical lead at an external surface of the packaging structure.