Analog Devices,inc.

Invensense, Inc.

Li Chen

Kuang L Yang

Thomas Kieran Nunan

Thomas Chen

Christine H Tsau

Mitul Dalal

Jeffrey A Gregory

Chen Yang

Yumeng Liu

Integrated circuit substrates having through silicon vias (TSVs) are described. The TSVs are vias extending through the silicon substrate in which the integrated circuitry is formed. The TSVs may be formed prior to formation of the integrated circuitry on the integrated circuit substrate, allowing the use of via materials which can be fabricated at relatively small sizes. The integrated circuit substrates may be bonded with a substrate having a microelectromechanical systems (MEMS) device. In some such situations, the circuitry of the integrated circuit substrate may face away from the MEMS substrate since the TSVs may provide electrical connection from the circuitry side of the integrated circuit substrate to the MEMS device.

Through silicon via (TSV) formation in integrated circuits

A microfluidic ion detector for detecting heavy metal ions in liquid and particulate matter from gas samples is described. The microfluidic ion detector includes a sample extraction structure for extracting sample ions from a sample liquid or extracting sample ions from the particulate matter of a gas sample, a separation structure for separating sample ions of different types once extracted, and a detection structure for detecting the sample ions. The microfluidic ion detector also includes a reference reservoir providing a reference ion against which the sample may be calibrated based on the operation of the separation structure. A portable, self-calibrating ion detector may be realized by including the described components on a single substrate.

Self-calibrated heavy metal detector

One or more conductive shielding plates are formed in a standard ASIC wafer top metal layer, e.g., for blocking cross-talk from MEMS device structure(s) on the MEMS wafer to circuitry on the ASIC wafer when the MEMS device is capped directly by the ASIC wafer in a wafer-level chip scale package. Generally speaking, a shielding plate should be at least slightly larger than the MEMS device structure it is shielding (e.g., a movable MEMS structure such as an accelerometer proof mass or a gyroscope resonator), and the shielding plate cannot be in contact with the MEMS device structure during or after wafer bonding. Thus, a recess is formed to ensure that there is sufficient cavity space away from the top surface of the MEMS device structure. The shielding plate is electrically conductive and can be biased, e.g., to the same voltage as the opposing MEMS device structure in order to maintain zero electrostatic attraction force between the MEMS device structure and the shielding plate.

Apparatus and method for shielding and biasing in MEMS devices encapsulated by active circuitry

A capped micromachined device has a movable micromachined structure in a first hermetic chamber and one or more interconnections in a second hermetic chamber that is hermetically isolated from the first hermetic chamber, and a barrier layer on its cap where the cap faces the first hermetic chamber, such that the first hermetic chamber is isolated from outgassing from the cap.

MEMs device with outgassing shield

One or more stopper features (e.g., bump structures) are formed in a standard ASIC wafer top passivation layer for preventing MEMS device stiction vertically in integrated devices having a MEMS device capped directly by an ASIC wafer. A TiN coating may be used on the stopper feature(s) for anti-stiction. An electrical potential may be applied to the TiN anti-stiction coating of one or more stopper features.

Apparatus and method for preventing stiction of MEMS devices encapsulated by active circuitry

A microchip has a base die with a conductive interconnect and an isolation trench around at least a portion of the conductive interconnect, and a cap die secured to the base die. A seal, formed from a metal material, is positioned between the base die and the cap die to secure them together. The microchip also has a blocking apparatus, between the isolation trench and the metal seal, that at least in part prevents the metal material from contacting the interconnect.

Microchip with blocking apparatus

A dual backplate MEMS microphone system includes a flexible diaphragm sandwiched between two single-crystal silicon backplates. Such a MEMS microphone system may be formed by fabricating each backplate in a separate wafer, and then transferring one backplate from its wafer to the other wafer, to form two separate capacitors with the diaphragm.

Dual single-crystal backplate microphone system and method of fabricating same

A method of etching a plurality of cavities in a wafer provides a wafer having a patterned hard mask layer. The patterned hard mask has open areas defining locations for first cavities and second cavities. A mask is applied to cover the patterned hard mask layer. The mask is etched to remove wafer material from areas defined by the second cavities. The mask is removed and etching then removes wafer material except as prevented by the hard mask layer. This leaves the first cavities with a first depth and further deepens the second cavities to a depth greater than the first depth. By suitably configuring the second cavities, a capped die can be formed by securing the wafer to a second wafer and removing at least a portion of the unsecured side of the first wafer to expose the second cavities, thereby forming a plurality of caps on the second wafer.

Method of etching a wafer

A MEMS apparatus has a substrate, a cap forming first and second chambers with the base, and movable microstructure within the first and second chambers. To control pressures, the MEMS apparatus also has a first outgas structure within the first chamber. The first outgas structure produces a first pressure within the first chamber, which is isolated from the second chamber, which, like the first chamber, has a second pressure. The first pressure is different from that in the second pressure (e.g., a higher pressure or lower pressure).

Sealed MEMS devices with multiple chamber pressures

Manufactured capped MEMS device wafers are tested for hermeticity on a vacuum prober at differing pressures or on a wafer prober at differing temperatures. Resonant frequency testing is conducted. Leaking MEMS devices are distinguished from the remaining MEMS devices on the basis of quality factor ('Q') measurements obtained from the resonant frequency testing.

Method of manufacturing MEMS devices with reliable hermetic seal

A method of forming a capped die forms a cap wafer having a top side and a bottom side. The bottom side is formed with 1) a plurality of device cavities having a first depth, and 2) a plurality of second cavities that each have a greater depth than the first depth. At least some of the plurality of second cavities each generally circumscribe at least one of the device cavities. The method then secures the cap wafer to a device wafer in a manner that causes a plurality of the device cavities each to circumscribe at least one of circuitry and structure on the device wafer. Next, the method removes at least a portion of the top side of the cap wafer to expose the second cavities. This forms a plurality of caps that each protect the noted circuitry and structure.

Method of etching and singulating a cap wafer

Microchip with blocking apparatus and method of fabricating microchip

A dual backplate MEMS microphone system including a flexible diaphragm sandwiched between two single-crystal silicon backplates may be formed by fabricating each backplate in a separate wafer, and then transferring one backplate from its wafer to the other wafer, to form two separate capacitors with the diaphragm.

Method of fabricating a dual single-crystal backplate microphone

A MEMS device has a first member that is movable relative to a second member. At least one of the first member and the second member has exposed silicon carbide with a water contact angle of greater than about 70 degrees.

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Belmont, MA, United States of America

Li Chen