Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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).
Abstract:
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.
Abstract:
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.
Abstract:
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.